class CommandRoot { protected:     string cmdString = "";     string title = "";     string tags = "";     string description = "";  public:     string getCmdString() {         return cmdString;     }     string getTitle() {         return title;     }     string getTags() {         return tags;     }     string getDescription() {         return description;     }      virtual bool onTrigger() {         return 1;     } };  class CmdFirst : public CommandRoot{     public:     CmdFirst() {         cmdString = "testing1";         title = "";         tags = "";         description = "";     }      bool onTrigger() {         cout << "C";         return 0;     } };  class Player {     NPC *target = NULL;     CommandRoot *cmdList[1];  public:     Player() {         cmdList[0] = new CmdFirst();     }      CommandRoot getCmdList(int n) {         return *cmdList[n];     }      NPC getTarget() {         return *target;     }      bool setTarget(NPC* t) {         target = t;         return 0;     }      string listen() {         string cmd = "";         cin >> cmd;         return cmd;     } };  int main() {     std::cout << "Hello World!\n";      Player* player = new Player();     NPC* firstNPC = new NPC();     player->setTarget(firstNPC);      bool exit = false;     do {         if (player->listen().compare(player->getCmdList(0).getCmdString()) == 0) {             cout << "A";             cout << player->getCmdList(0).onTrigger();         }         else         {             cout << "B";         }     } while (exit == false); }   The following line is calling the parent's virtual function instead of the derived class.  cout << player->getCmdList(0).onTrigger();   I have a feeling it's because the data type of the array is the parent class, but that shouldn't prevent the array element from being assigned the data type of the derived class, then calling that class's function.

Someone mentioned it in the IRC as the slicing problem.


As a new user, I've just installed Lubuntu 20.10 64bit alongside Windows7 on a Intel Core 2 laptop. I've managed to change the default boot to W7 by editing and updating the GRUB file. The displayed boot order is now Lubuntu, then a few options for mem test etc and then Windows 7 at the bottom. I'd like to have LU and W7 adjacent in the menu, with the options below - I'm probably not going to use them anyway.

So basically I have a pretty flooded Grub bootloader, with older linux versions, 3 operating systems and memtests. What I want is to leave the operating systems only. I need to know how to do it manually, and I need someone to tell me what should I be aware of when a new kernel is released. Thanks in advance.


Prove that $f(n)=n^5+n^4+1$ is composite for $n>1, n\in\mathbb{N}$.   This problem appeared on a local mathematics competition, however it looks like there is no simple method to solve it. I tried multiplying it by $n+1$ or $n-1$ and then tried factorizing it, but it was too tough for me.  Any help will be appreciated.

Find a prime factor of $A=14^7+14^2+1$. Obviously without just computing it.


I am using TeXnicCenter to write my latex document. I am formatting my section heading using following command:   \titleformat{\section}{\normalfont\fontsize{14pt}{14pt}\selectfont\bfseries\MakeUppercase}{\thesection}{1em}{}   This command is working fine, but when I include package "color" it starts giving me error. Please let me know, how to correct it.  Following is the error:   Missing number treated as zero Color stack action is missing   It also display "POP" in the section heading in pdf file.  Following is the sample code:    \documentclass[12pt]{report}   \usepackage{url}   \usepackage{color}    \usepackage{graphicx}    \usepackage{amsmath}     \usepackage{epstopdf}      \usepackage{cite}      \usepackage[T1]{fontenc}      \usepackage[a4paper]{geometry}     \geometry{verbose,tmargin=3cm,bmargin=2.5cm,lmargin=2.5cm,rmargin=2.5cm}      \usepackage{titlesec}        \titleformat{\section}{\normalfont\fontsize{14pt}{14pt}\selectfont\bfseries\MakeUppercase}{\thesection}{1em}{}        \begin{document}       \chapter{NewChap}      \section{Hello}      \end{document}

I would like to make colored, upper case section titles. But somehow, the translation for all section items fails with:   ! Missing number, treated as zero. <to be read again>  ! Color stack action is missing. <to be read again>  ! Package xcolor Error: Undefined color `BLUE'.   I figured out that the conflict occurs when I am trying to combine the \MakeUppercase command in the \titleformat environment together with the xcolor package.  A MWE of my problem:  \documentclass{article}   \usepackage{xcolor} \usepackage{titlesec}  \titleformat{\section}   {\normalfont\bfseries\MakeUppercase}{\thesection}{1em}{}  %this line does not work  %{\normalfont\bfseries}{\thesection}{1em}{}                %works perfectly well  \begin{document} \section{\color{blue} This is a blue, upper case section} \end{document}   I work with Texmaker/MikTeX 2.9. Any ideas how this issue can be solved?


I read the  and  on this topic, and the rules there do not seem correct.  I  an answer as a comment, and the owner thanked me without citing @Alex, and I got his comment as a notification.  I then replied, and he replied (without citing me again), and I got his comment again.  What are the full rules of who gets notified on comments?  I would like to avoid writing @Username whenever they would get my comment anyways.

How do the comment replies (aka "pinging users") work?  Who can I send an @reply to? How do I respond to a specific user when entering my comment? Will they be notified? What do people mean when they talk about "pinging" another user?  Related:


When I tried to search with site:spgeeks.devoworx.com I got only the below 4 results!    I am facing this issue 2 months ago and I can't trace my issue and there's no error in the search console! (only excluded URLs (not post URL)) Could you please help me to know why my site is not indexed in google?     P.S: I am not facing the same issue in bing and yahoo only in google!

This is a general, community wiki  question and answer pair intended to address any questions   concerning the reasons a site or specific site contents do not appear   in search engine results.      If your question was closed as a duplicate of this question and you   feel that the information provided here does not provide a sufficient   answer, please open a discussion on .   My site (or specific pages on my site) is not appearing in search engine results.  Why isn't my content indexed and what can I do about it?


I want to avoid repeating the following code many times since I use plenty VBOs:     glBindBuffer(GL_ARRAY_BUFFER, VBOs[0]);     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices1), vertices1, GL_STATIC_DRAW);      glBindBuffer(GL_ARRAY_BUFFER, VBOs[1]);     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices2), vertices2, GL_STATIC_DRAW);      glBindBuffer(GL_ARRAY_BUFFER, VBOs[2]);     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices3), vertices3, GL_STATIC_DRAW);      glBindBuffer(GL_ARRAY_BUFFER, VBOs[3]);     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices4), vertices4, GL_STATIC_DRAW);   I tried to simplify this code with a cycle. Here is what I tried to do: std::string aux = "vertices";     std::string aux2;     int aux3;     std::string aux4;      const void* aux5;     for (int i = 0; i <= 13; i++) {         aux3 = i++;         aux4 = std::to_string(aux3);         aux2 = aux + aux4;         aux5 = aux2.c_str();         glBindBuffer(GL_ARRAY_BUFFER, VBOs[i]);         glBufferData(GL_ARRAY_BUFFER, sizeof(aux2), aux5, GL_STATIC_DRAW);     }  It didn't work out. It still shows a figure with the last color I used but doesn't paint the other figures. Is there a way to make that cycle work or should I continue repeating the code like above? Thanks for the help. I also tried simplifying the VAOs section in the code with a cycle and it worked. Here is how I did it: glGenVertexArrays(14, VAOs);      for (int i = 0; i <= 13; i++) {          glBindVertexArray(VAOs[i]);         glBindBuffer(GL_ARRAY_BUFFER, VBOs[i]);         glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);         glEnableVertexAttribArray(0);     }

How do I determine the size of my array in C?   That is, the number of elements the array can hold?


So I started my computer and realized that I can no longer Fn+F2 or Fn+F3 to change my volume, after closer inspection I realized that the option to change my volume is somewhat corrupted.  I then went to the sound settings, and the menu is completely broken.  Last time I did something, I installed PulseAudio, but I just tried reinstalling it and its still not working. Update 1: Booted from the Unity Control Center and the problem still persists there, so its probably not an issue with gnome.

On my fully updated Ubuntu 18.04.3 system, audio doesn't work unless I switch between outputs. When I boot my PC, the right output (stereo speakers) is already selected by default, but there is no audio from Chromium, Firefox, VLC or any other program. However, the GNOME speakers test works. I can hear "front left" and "front right" from there, but no audio from other programs. In order to fix that, I can simply switch to another audio output (e.g. HDMI out) and then switch back to the stereo speakers, and the audio will magically work. Any idea why? It's not a big deal because it takes a couple of seconds to switch between outputs, but it's kind of annoying to do that after every reboot.


They changed Thanos' motivation for killing half the universe's population in the movies.  In the comics, he did it to impress Mistress Death.  In the movie, his reasoning was to reduce overpopulation in a universe of finite resources.  While halving the population keeps the number in line with the comics, it makes no sense.  Take Earth as an example.  Earth has a population of 7.4 billion people.  Reducing the population in half brings us to 3.7 billion people.  This was the population in 1970.  He set us back 50 years.  And in reality, it will not take 50 years to recover, as science has progressed since 1970.  This means people live longer, healthier lives.  People can have children later in their lives.  Diseases will have little to no affect as they did 50 years ago.  Childbirth is safer etc.  This being the case, Thanos would have to halve the population at least once every 50 years.    I doubt it, but is there any other explanation?  Perhaps in a tie-in comic?

If I had a gauntlet with essentially unlimited power, and my goal was to help make sure life in the universe was able to prosper, then my first thought toward this goal probably would not be      to extinguish half of all life.   This doesn't directly help anyone, and it is, at best, a temporary solution, since      populations will eventually grow back.   Assuming that I am not, in fact, secretly in love with an avatar of death itself, why would I choose to      commit universal genocide   instead of directly solving the limited resource problem?  So, to be specific, my question is: In-universe, what is Thanos's motivation for attempting to do this instead of more reasonable alternatives?


I know that there are several types of resurrection skills in LoL. What do I mean by the "resurrection" term?  Following skills and items can be categorized under the term "resurrection":   Champion Passive - Aatrox Passive  Item - Guardian Angel  Champion Skill - Yorick - Ulti  Champion Skill -Zilean - Ulti   To combine all of this, all of the other skills and items should be used on Aatrox. I'm just curious about what order these skills will take effect? Assuming;   Skills used just before first death  There is continuous damage that is applied on the champion Aatrox (say 3k true damage per second)   With above assumption what will happen? Has anybody ever tried this?  Note: If I forgot to mention any skill, passive or item that resurrects the applied champion please indicate them, too.

In League of Legends, there are a number of effects which revive a champion upon death.  The item  is the most well-known and widely used of these.  I was wondering, however, whether its effect would come before or after other revive effects?  I have two examples.  First, Zilean's ultimate  will provide a champion with a Guardian Angel -like buff for a limited time.  If a champion has this buff in addition to a Guardian Angel, which effect will happen first?  Second, Anivia's passive  allows her to come back to life if her egg is not destroyed after she is killed.  If she has a Guardian Angel, will her passive be triggered before or after it? How does this compare to  and ?  It seems like in one case it is more beneficial to have Guardian Angel's precedence be greater, and in the other it is more beneficial to have it be less.  In the first scenario, if the Guardian Angel was triggered first, then Zilean would have a good chance of simply wasting his ultimate.  On the other hand, if it is triggered after these revival effects, then Anivia could not get the full benefit of her passive.  Is there a set order of precedence, or does each revival effect have their own unique "priority level" that is explicitly detailed for each ability?


I know, there are a lot of peoples asking this, and I followed every single guide, but I REALLY DO NOT found the "calendars link" and so I can't keep following the guide...Has google changed the layout or something else, I don't know. But I really need to fix this mail problem, even apple support has said to me "There is no solution for this problem at the moment, keep your macbook up to date". Really thanks to those that can help me.

When I am doing some work on my macbook pro, Mail app's main window keeps popping up in the background, it even pops up when I watch movies by interrupting full screen. This is so frustrating, I can't find out solution to this, googled and went to many discussion forums, no luck, suggestions that I found are very old and outdated. Has anyone faced similar issues or does anyone knows solution to this?


In the sidebar in the iOS app, the "history" button keeps freezing the app for about thirty seconds, after which it either finally loads or the app crashes. I have been unable to find a pattern for when it does which.  I have tried closing the app from multitasking during that window, and the app takes a good 10-15 seconds to open afterwards.    App Version: 1.6.3.6 Device: iPhone SE OS Version: Version 10.2.1 (Build 14D27)

Trying to open recently viewed tab hangs iOS app for a several seconds.        Probably this occurred due retrieving too many items.   App Version: 1.6.3.6 Device: iPad Air 2 (Wi-Fi) OS Version: Version 10.2 (Build 14C92)


i am trying to setup a dropdown menu, that can be closed by clicking outside (the opened div) and by clicking the button/img (that opens the div).  Image with onclick funtion:     Dropdown list that should be opened and closed, class declares dropdown as display:none:

...

   This is my solution so far:  function hide() {     var x = document.getElementById("dropdown");      if (x.style.display === "none") {         x.style.display = "block";     } else {         x.style.display = "none";     } }   When i am trying to add a function that closes the dropdown when the user clicks outside the dropdown:  window.addEventListener('mouseup',function(event){         var dropd = document.getElementById('dropdown');          if(event.target != dropd && event.target.parentNode != dropd){             dropd.style.display = 'none';         } });   Then i end up with a opened dropdown because the onclick-function starts.  Can someone help me to combine those functions? Thank you!

I have some HTML menus, which I show completely when a user clicks on the head of these menus. I would like to hide these elements when the user clicks outside the menus' area.  Is something like this possible with jQuery?  $("#menuscontainer").clickOutsideThisElement(function() {     // Hide the menus });


I have created one Java Software in that I want to call .net webservice.   How to make it possible ?  I see some examples but I don't find any perfect solution.

I have a very simple SOAP web service that I need to consume from a Java client.  What is the easiest way to accomplish this without using any third party libraries?  A requirement is that the host and port is read from the web.xml before every call to the ws.


I am new to using Linux, I have always used Windows in the past. My question is regarding the Ubuntu Software station where you can download new software and stuff. I have yet to try to download anything, but when I have tried deleting certain programs it doesn't always work. Half the time I click "Installed" or "Updates" at the top it just continuously loads and goes nowhere. I have yet to be able to access the updates tab but I can see I have 14 available updates. When I have tried deleting programs they sometimes actually are deleted, but sometimes it just says removing and never changes, or it will finish but once I close the Ubuntu software program and return to it, the program I deleted is once again under the "Installed" tab. I am decent with computers but by no means a programmer or anything, I have never used anything like Terminal so any options with that will only get me lost, although I do hope to become better with Terminal.  Any tips or tricks to get the Ubuntu Software "Store" to work properly?

After upgrading to Ubuntu 16.04, I tried to use the new software center that came along with it, but I found it to have a few issues. One, it didn't detect all the applications I had previously installed and two, whenever I tried installing new software with it, a new icon on the launcher (saying "Waiting to Install") appears, but no progress is made and the icon is stuck on the launcher.   However, I don't encounter any of these issues in the older Software Center. Does anybody know why this may be?


I'm planning on setting a dual-boot machine with Windows (8.1) and Debian sitting on different partitions of an SSD.  The problem here is my 1.5TB storage drive. I'm planning to use Windows and Debian equally, so I need to format this drive in a way that it works as good as possible on both systems. There's also an additional requirement: Windows should be able to flawlessly work with user folders moved to the storage drive.  So far I'm only looking to the following options:  1) FAT32 is not actually an option, but worth mentioning for others to see, if your storage partition is 32GB or smaller than this is perfect;  2) NTFS. Both Windows and Linux can work with this filesystem, but Linux will probably show very high CPU usage while working with NTFS partitions;  3) Ext4 seems to be the best option, but I can't find any info about how well does Windows handle it. Ext2sd, as well as Paragon software, don't have any information on performance, I'm afraid of it being worse than NTFS in Linux. Also I have no idea how well does it combine with Windows user folders.  Are there any other options I've overlooked? Perhaps, NTFS isn't that bad on a fairly powerful machine? Is EXT4 perfect for this scenario, or it's going to a huge pain to make it work decently on Windows?

What is the best filesystem to use cross-platform (Linux, Windows, OS X) which supports disk sizes of at least 2TB and file sizes >4GB?  I'm planning to use it on a USB drive on different computers.  Are there any filesystems that can be used on all the named OSes without installing additional drivers?


I have both Japanese and Philippine passports, but my surname is different on each. I have never been to Japan; I was born and raised in the Philippines.   This is my first time traveling to Japan. Which passport should I use for my flight ticket? What should I do when I get to Japan?   I don't have any idea as this will be my first time traveling abroad.

I am a citizen of two different countries, and have two passports.  How should I use my passports when traveling?


I've been making a beauty and the beast animation for a school project. and I've created a particle system that sort of creates streaks coming from a single vertex however it will only show in 3D view solid mode. so it wont render in my final product could someone pls tell  me why? Sorry if it's obvious i am reasonably new to blender.

I am an inexperienced user of blender, and created a scene of a manikin using blender  2.69 and rendered it using cycles  to produce a .png image which I was very happy with. I wanted to progress further and incorporate the use of Halo particles with this scene, but discovered that cycles will not render halo particles. (I looked at the 'dupli'  option but this won't give the same effect as a BI halo particle when rendered).  Question 1 - will the new version of blender  - v 2.74  using Cycles render halo particles or do I have to retreat to Blender Internal - BI (Blender render).  Assuming it probably won't, I opened my blender file and attempted to render my scene using blender Internal.  The result was  a complete blacked out manikin and only a white floor visible.  Question 2.  Am I going to have to start all over again, because I need to use the halo features of BI and using cycles seemed to have put me up a blind alley, or is there something on my current file that I could change/focus on so I can get it to render (and therefore use the halo features) with BI.


In a sentence we find a word in inverted commas or a single letter. Why? Example 1: My 'first' experience of ... Example 2: The letter 'g' in the word gnaw is silent

I was reading an article   in 4th paragraph the author says     When I visit Cai (as everyone calls him, pronouncing it “Tsai”) in his spare East        Village Manhattan studio with a big red door and a feng shui stone lion guarding the        entrance within, we sit at a glass table flanked by wall-size wood screens: his gunpowder “drawings.”   I didn't understand why author puts drawings in double quotes. If you read the article, he has used it for many other words like  “signs”, “crop circle”.  My question is what the intends by putting the words in double quotes?


"He forgot his enmity to Manfred, whom he saw but little hope of dispossessing by force; "  I'm reading a novel called The castle of Otranto.   And I'm confused the usage of 'but' in the sentence above.   Does it have the same meaning without 'but' ,and 'but' can be removed?  Thank you for reading!

Every now and then I stumble about a construction like this:     It was but something....   and I understand it to be      It was nothing but....   or     It was only...   depending on the context.  I do know what this "but" means and I do know what else "but" can mean. My question is this?  Is the a difference between "but" and "nothing but" in this context, be it ever so small and hidden in tone or emphasis? Is there such a difference between "but" and "only"? And finally is "but" in this context something you can say or does that make you sound way out there? Thanks a lot


EDIT:  Object result = JSON.deserializeUntyped(payload);  if (result instanceof Map<String, Object>) {     Map<String, Object> resultMap = (Map<String, Object>)result;     system.debug('result: ' + resultMap.get('records')); //returns null }   //END EDIT  How to loop through the nested json key/value for an example how can I get the values for this attributes Records==>attributes==>url or Metadata=>formula  APEX Code:  String payload = '.... json...' Map<String, Object> jsonMap = (Map<String, Object>)JSON.deserializeUntyped(payload);       List<Object> records = (List<Object>) jsonMap.get('records'); //get the records if (records != null) {     for (Object r : records) {         //for (string r2 : r.get('url')) {  //error incorrect signature              system.debug(r.value);         //}     } } else {     system.debug('null.. : ' + records); }   JSON  {   "size": 1,   "totalSize": 1,   "done": true,   "queryLocator": null,   "entityTypeName": "CustomField",   "records": [     {       "attributes": {         "type": "CustomField",         "url": "/services/data/v46.0/tooling/sobjects/CustomField/00N6g00000TAlZNEA1"       },       "Metadata": {         "businessOwnerGroup": null,         "businessOwnerUser": null,         "formula": "IMAGE( \nCASE(Rating__c, \n\"Very Bad\", \"/img/samples/stars_100.gif\",\n\"Bad\", \"/img/samples/stars_200.gif\",\n\"Okay\", \"/img/samples/stars_300.gif\", \n\"Good\", \"/img/samples/stars_400.gif\", \n\"Very Good\", \"/img/samples/stars_500.gif\", \n\"/img/samples/stars_000.gif\"), \n\"rating\")",         "formulaTreatBlanksAs": "BlankAsZero"       }     }   ] }

This is a canonical question and answer developed by the community to help address common questions. If you've been directed here, or your question has been closed as a duplicate, please look through the resources here and use them to shape more specific questions. To browse all canonical questions and answers, navigate to the  tag.  This question and answer is owned by the community! If you can improve it and make it more useful, you're welcome to edit it.  I have a specific JSON structure in mind. I need to either deserialize this structure that's coming in from a web service, or I need to serialize data into this structure to transmit it to another system. How should I get started on this project in Apex?


So I'm stuck with the question: Find the radius of convergence for the power series:  $$f(z) = \sum^{ \infty}_{j=0} 2^{j} z^{j^2}$$  My issue is that there are two solutions depending if the $a_{n}$ is a perfect square or not, how should I approach this problem? Thanks in advance!

What is the radius of convergence of this power series here?   $$\sum_{n=1}^{\infty}2^n x^{n^2}$$


Find the number of ways to simultaneously select $3$ pebbles from $9$ pebbles that are arranged in a circle such that no two of the three selected pebbles are adjacent to each other, and one selection is the same as another rotation if the former can be rotated to form the latter.  My Solution: At first, we can pick any $9$ points. Then, any $6$ points. And at last, $4$ points. This turns out be $6\cdot4\cdot9$. However, we have over-counted. We divide this by $3$! because we do not care about the order. Lastly, we divide by $9$ to account for the last part of the problem. Answer: $4$  Is this correct? And is there an easier way using combinatorics?

0 choices for the 1st person.  17 choices for the 2nd person (must exclude 1st and his/her two neighbours)   For 2 of these choices of 2nd person, there is one shared neighbour, so 15 remaining choices. (e.g. if they are numbered 1 to 20 in a circle, 1st person is #1, 2nd is #3, then people 20,1,2,3,4 are excluded).  For the other 15 choices of 2nd person, there are no shared neighbors, so 14 remaining choices.   So if order matters, total is $20 \cdot (2 \cdot 15 + 15 \cdot 14) $ but since order does not matter, divide by $3! = 6$ to account for the permutations in order of the 3 people.  So total = $20 \cdot \frac{2 \cdot 15 + 15 \cdot 14}{6}$  just redid it; does this make any sense?


I’m using CentOS and can’t figure out how to:   Show list of current background processes/jobs (which I run). How to run process in background. How to stop background’s process.   My command that I want to run in background looks like this:  activator run   So far I found only this command (that runs process in background).  nohup activator run &

I'm trying to create a script which starts some programs  startup.sh  knetworkmanager emesene keepassx   The problem is that when I run the script, it only starts knetworkmanager. This is because it'll start it, then wait until it's finished. How can I start a program without waiting for it? I don't think I can just add "&" after each command, because all processes will still be killed when the script is finished.


It can either rain, or snow, or do both, or neither. There is a $15\%$ chance that it is snowing right now. There is a $10\%$ chance that it is raining right now. Each is independent of the other. What is the chance that it is either raining or snowing right now, but not both?

There's a 10% chance it will rain today. There's a 15% chance it will snow today.   What percentage chance is it that it will:   Both rain and snow (it can both rain and snow at the same time)? Neither rain nor snow? -   Raining and snowing are independent of each other.  EDIT: (ADDED)   Rain or snow but not both?


I stumbled over a strange thing.  I have a model class where you can get values of attributes via a model.get(attributeName) function.  So I did this in a view:  var mapModel = new Ex.Models.MapModel(model); var view = new Ex.Views.MapView(mapModel);  var d = this.model.get('layerIds'); d.mapLayer = view.getId();  console.log("layerIds", this.model.get('layerIds'));   The attributes layerIds.mapLayer is set to null by default. If I set it to the views id (e.g. 43) I'd expect that the console.log would still return {mapLayer: null} since I create varaible d to copy the value of this.model.get('layerIds') and work with that value independent from the models value.  But if I execute this piece of code the log says:  {mapLayer: 43}   Why is this? Why do Javascript variables keep track of their copied values and update their own value if one of the others changed?  And how can this be stopped?

What is the most efficient way to clone a JavaScript object? I've seen obj = eval(uneval(o)); being used, but . I've done things like obj = JSON.parse(JSON.stringify(o)); but question the efficiency.  I've also seen recursive copying functions with various flaws.  I'm surprised no canonical solution exists.


I've been following a lot of issues here that relates to this one - so it might be a possible duplicate, however since I didn't see it for 20.04 version, I think it's a new one. The issue is:  I have installed (via USB that contained a downloaded version from Official website) the Ubuntu 20.04 new OS. - Please note this is a fresh installation. After rebooting, the keyboard and mousepad are just not working. They are working if I am getting to tty (for example) / BIOS, however not in the login page / in the OS.  I have followed each and any guide here about installing / updating xserver-xorg-input-all again and again, however this isn't seems to solve the issue. Hardware: Architecture:        x86_64     product: Inspiron 7348 (0675)        product: 067RT2           product: Intel(R) Core(TM) i7-5500U CPU @ 2.40GHz              product: HMT41GS6BFR8A-PB           product: Broadwell-U Host Bridge -OPI              product: HD Graphics 5500              product: Broadwell-U Audio Controller              product: Broadwell-U Processor Thermal Subsystem              product: Wildcat Point-LP USB xHCI Controller                 product: xHCI Host Controller                    product: USB Receiver                    product: ST_SENSOR_HUB                    product: Integrated_Webcam_HD                    product: Touchscreen                 product: xHCI Host Controller              product: Wildcat Point-LP MEI Controller #1              product: Wildcat Point-LP High Definition Audio Controller              product: Wildcat Point-LP PCI Express Root Port #3                 product: Wireless 7265              product: Wildcat Point-LP USB EHCI Controller                 product: EHCI Host Controller             product: Wildcat Point-LP LPC Controller              product: Wildcat Point-LP SATA Controller [AHCI Mode]                 product: LITEONIT LCS-256              product: Wildcat Point-LP SMBus Controller              product: Wildcat Point-LP Thermal Management Controller           product: PnP device PNP0c02           product: PnP device PNP0b00           product: PnP device INT3f0d           product: PnP device PNP0c02           product: PnP device PNP0303           product: PnP device DLL065a           product: PnP device PNP0c02           product: PnP device PNP0c02        product: DELL 0WF28498        product: OEM Define 5  My questions:  Did anyone else suffer from this problem? Where you reboot - install the xserver using an external (for example) keyboard and mouse - then it works. Then after another reboot - it does not work? Specifically after upgrading to 20.04!  How can I solve it? Please assist as it is a critical issue!

I'm on an Acer Aspire E5 and I haven't been able to get my laptop's onboard keyboard and trackpad to work, although the trackpad is detected as a Synaptics, and the keyboard is showing as an AT Translated Set 2 keyboard. External mouse and keyboard works fine, and are what I am currently using. I already checked whether I'm on Synaptics or Libinput, although I was fairly certain that upgrade happened a few years ago, and I am definitely using libinput, which I reinstalled, to no avail. I've made sure that the trackpad is enabled in the system settings, and I've switched it from advanced mode to basic in the BIOS, which for some seemed to have been the solution I'd like to note that the onboard keyboard works fine on boot, and its only when X is loaded (i'm assuming) that it fails. I have just recently installed Kubuntu on this machine after grappling with the same issue on Arch, thinking i had done something wrong in the installation. On Arch, I had no trouble using the keyboard on the TTY and live-USB (Arch and Ubuntu), but when i installed X for a GUI, they both stopped working. What should my next steps be?


If I have 2 end points how can I generate values for the Sigmoid function?

Quick formulation of the problem: Given two points: $(x_l, y_l)$ and $(x_u, y_u)$ with: $x_l < x_u$ and $y_l < y_u$, and given lower asymptote=0 and higher asymptote=1, what's the logistic function that passes through the two points?  Explanatory image:   Other details: I'm given two points in the form of Pareto 90/10 (green in the example above) or 80/20 (blue in the example above), and I know that the upper bound is one and the lower bound is zero.  How do I get the formula of a sigmoid function (such as the logistic function) that has a lower asymptote on the left and higher asymptote on the right and passes via the two points?


I'm trying to install openvpn however I am running into a problem where Ubuntu is complaining about unmet dependencies:  [sudo] password for keith:  Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies:  linux-image-extra-4.4.0-71-generic : Depends: linux-image-4.4.0-71-generic but it is not going to be installed  linux-signed-image-4.4.0-71-generic : Depends: linux-image-4.4.0-71-generic (= 4.4.0-71.92) but it is not going to be installed  openvpn : Depends: libpkcs11-helper1 (>= 1.11) but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).   When I try to run apt-get -f install I'm met with these errors:  dpkg: error processing archive /var/cache/apt/archives/linux-image-4.4.0-71-generic_4.4.0-71.92_amd64.deb (--unpack): cannot copy extracted data for './boot/System.map-4.4.0-71-generic' to '/boot/System.map-4.4.0-71-generic.dpkg-new': failed to write (No space left on device) No apport report written because the error message indicates a disk full error   If I run df -h I see the below:  Filesystem                    Size  Used Avail Use% Mounted on udev                          208M     0  208M   0% /dev tmpfs                          46M  5.2M   41M  12% /run /dev/mapper/temptus--vg-root  8.3G  6.7G  1.2G  86% / tmpfs                         228M  4.0K  228M   1% /dev/shm tmpfs                         5.0M     0  5.0M   0% /run/lock tmpfs                         228M     0  228M   0% /sys/fs/cgroup /dev/sda2                     473M  470M     0 100% /boot /dev/sda1                     511M  3.6M  508M   1% /boot/efi tmpfs                          46M     0   46M   0% /run/user/1000 /home/keith/.Private          8.3G  6.7G  1.2G  86% /home/Keith   As you can see, /dev/sda2 (/boot) is 100% used. I tried following , which does free up space in /boot, however when I remove old kernels and finally run apt-get -f install, the space required always increases more than what I cleared.  For example, if I manage to run apt-get -f install before removing kernels it tells me I need 66.4mb of free space. But if I remove a kernel (4.4.31 for example), it increases to 122mb of free space and wants to reinstall whatever kernel I removed.  Is there a way to forcefully remove kernels and have Ubuntu not reinstall after running sudo apt-get -f install?  Thanks!

I got an error message explaining my /boot is full. trying to clean up old image files always seems to fail because of disk full errors or dependency errors. Could someone explain where I’m going wrong.   $ sudo apt-get autoremove Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run ‘apt-get -f install’ to correct these. The following packages have unmet dependencies.  linux-image-extra-3.13.0-44-generic : Depends: linux-image-3.13.0-44-generic but it is not installed  linux-image-extra-3.13.0-45-generic : Depends: linux-image-3.13.0-45-generic but it is not installed  linux-image-generic : Depends: linux-image-3.13.0-45-generic but it is not installed E: Unmet dependencies. Try using -f.  $ ls /boot abi-3.13.0-32-generic         initrd.img-3.13.0-43-generic abi-3.13.0-36-generic         lost+found abi-3.13.0-37-generic         memtest86+.bin abi-3.13.0-39-generic         memtest86+.elf abi-3.13.0-40-generic         memtest86+_multiboot.bin abi-3.13.0-43-generic         System.map-3.13.0-32-generic config-3.13.0-32-generic      System.map-3.13.0-36-generic config-3.13.0-36-generic      System.map-3.13.0-37-generic config-3.13.0-37-generic      System.map-3.13.0-39-generic config-3.13.0-39-generic      System.map-3.13.0-40-generic config-3.13.0-40-generic      System.map-3.13.0-43-generic config-3.13.0-43-generic      vmlinuz-3.13.0-32-generic grub                          vmlinuz-3.13.0-36-generic initrd.img-3.13.0-32-generic  vmlinuz-3.13.0-37-generic initrd.img-3.13.0-36-generic  vmlinuz-3.13.0-39-generic initrd.img-3.13.0-37-generic  vmlinuz-3.13.0-40-generic initrd.img-3.13.0-39-generic  vmlinuz-3.13.0-43-generic initrd.img-3.13.0-40-generic   I used   kernelver=$(uname -r | sed -r 's/-[a-z]+//') dpkg -l linux-{image,headers}-"[0-9]*" | awk '/ii/{print $2}' | grep -ve $kernelver   to get   linux-headers-3.13.0-32 linux-headers-3.13.0-32-generic linux-headers-3.13.0-36 linux-headers-3.13.0-36-generic linux-headers-3.13.0-37 linux-headers-3.13.0-37-generic linux-headers-3.13.0-39 linux-headers-3.13.0-39-generic linux-headers-3.13.0-40 linux-headers-3.13.0-40-generic linux-headers-3.13.0-44 linux-headers-3.13.0-44-generic linux-headers-3.13.0-45 linux-headers-3.13.0-45-generic linux-image-3.13.0-32-generic linux-image-3.13.0-36-generic linux-image-3.13.0-37-generic linux-image-3.13.0-39-generic linux-image-3.13.0-40-generic   Then picking the first image to remove   $ sudo apt-get purge linux-image-3.13.0-32-generic Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies.  linux-image-extra-3.13.0-32-generic : Depends: linux-image-3.13.0-32-generic but it is not going to be installed  linux-image-extra-3.13.0-44-generic : Depends: linux-image-3.13.0-44-generic but it is not going to be installed  linux-image-extra-3.13.0-45-generic : Depends: linux-image-3.13.0-45-generic but it is not going to be installed  linux-image-generic : Depends: linux-image-3.13.0-45-generic but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).


If not a bug, this at least is inconsistent behavior.   Go to any  or  page, say for 'bug'. Check the list of related tags, note 'bug' itself is not present. The  page, however, has 'bug' at the top of the list of related tags.     Similarly, any tag is listed at the top of the 'Related tags' list on the 'Top users' page, but not elsewhere.

Only seems to be for the "Top Users" page of a tag.  Confirmed for multiple sites and tags.


Ok, I have in mind that a picture P can be represented by a two dimensional matrix A where each element of A (aka every pixel) is a vector with four coordinates (Red,Green,Blue). What extra stuff is encoded in a RAW file except this matrix?

I know people use fancy software like Lightroom or Darktable to post-process their RAW files. But what if I don't? What does the file look like, just, y'know, RAW?


Is there a way to make the ‘send’ button get pressed automatically (programmatically)?

Does anybody know if it's possible, and how, to programmatically send a SMS from the iPhone, with the official SDK / Cocoa Touch?


I don't like the idea that my personal information are gathered and by some company that make profit out of processing and selling it (or even when it has a possibility to do so). And yes, that's the reason I don't use Facebook and gmail (after reading their TOC).  I wonder if it's possible to use the Android smartphone without Google account at all in a long time?  So far I know that:   I don't use gmail/google+/chrome, so I don't bother about it. I cannot download application from Google Play without Google account, but I can download most of them as .apk and install manually.   Did I miss something? Or it's possible to live with Android without Google account?  p.s. Does Google still collect any data about me, even when I just use Android, without Google account and without gmail/google+/youtube?

I have a Sony Xperia Z with version 4.1.2 running.  My question is about removing all of the Google baggage from the phone.  I have no Google account tied to my phone and would really like to get rid of all traces of Google from my phone for a few reasons:   Battery performance: Google services ranks in the top 3 of what uses up my battery Privacy: I try to minimize what Google siphons from my phone with the exception of Google maps Less Dependency: I don't want to be dependent on one company for all my needs.   So are there any Android versions out there that are minimalistic and do not invade your privacy?


I am still getting used to Javascript (I'm coming from C++) and would like to add a new function to String which mutates the string instance directly. Let's say that I want to add a new character at the midpoint of the string (ignoring any error checking). In C++ you could do something like this->value = .... Is that the way to do this in Javascript? TIA  String.prototype.mutateSelf = function(param1) {   // How do I mutate this specific string instance?   return this; };

Does javascript use immutable or mutable strings? Do I need a "string builder"?


A friend who is learning English asked me this question today and I was unable to give a definitive answer on grammar.  The phrase constructions below are quoted verbatim from them :   An English person generally has a pet  English people generally have a pet   English people generally have pets   Posibilities of tidying up the  phrase construction aside, specifically in terms of the grammar:  My thinking is:   (1) is incorrect, although I am toying with the idea that perhaps (at a push !) with a more specific subject it could be acceptable (e.g. a blind person generally has a guide dog) (2) and (3) are largely interchangeable, but if you were being strict about grammar, (3) would be the correct answer because of the plural subject.   However I would be interested to know what the specific grammar rules are in relation to generic constructs (both for my own interest and that of my friend).

In English, generic reference takes three possible forms:  A. Cats are cute. B. A cat is cute. C. The cat is cute.  But the names of nationalities seem to me to make an exception to this rule. As far as I know, when referring to all the members of a nation, you can only use the C version: The Italians are musical, or The French are posh, or The British are cold. Why is it that in this case only C is considered grammatically correct? If all the Italians, or all the French, or all the British are musical, posh, or cold, why can't we also say:  A. *Italians are... // *French are... // *British are...  or  B. *An Italian is... // *A French is... // *A British is...  ?


let $(X,\leq)$ and $(Y,\preceq)$ be well-order sets and they are isomorphic.  Prove that there is one isomorphism between $X$ and $Y$.   Notice that $X$ and $Y$ are sets, so by isomorphism I mean isomorphism between sets.

I need to show specifically using transfinite induction that given two well-ordered sets $\left(A,<_{1}\right)$   and $\left(B,<_{2}\right)$ there is only one isomorphism between them. To do this I want to show by induction that there is only one way to define the mapping and that is: $$\forall\, x\in A: \varphi\left(x\right)=\min\left(B\backslash\varphi\left(\left\{ a\in A\,:\, a<_{1}x\right\} \right)\right)$$ Showing the base of the induction is no problem and the induction hypothesis would be that $$\forall\, y<_{1}x\,:\,\varphi\left(y\right)=\min\left(B\backslash\varphi\left(\left\{ a\in A\,:\, a<_{1}y\right\} \right)\right)$$ My problem is that I can't seem to manage to use the hypothesis in order to prove the step. I've found a couple of ways to show this definition of the mapping is indeed necessary but none of those used the induction hypothesis. My plan was to mark $$c_{0}=\min\left(B\backslash\varphi\left(\left\{ a\in A\,:\, a<_{1}x\right\} \right)\right)$$ Using the fact $\varphi$ is surjective take $y\in A$ such that $\varphi\left(y\right)=c_{0}$ and show that it can't be that $y<_{1}x$ or $x<_{1}y$ and thus necessarily $y=x$. If someone could give me a way to show either one of these are false using the induction hypothesis it would solve my problem.  Thanks a lot!


Can time machine or iCloud backups overcome ransomeware encryption of your hard drive?

These days, malicious software seems to be infecting Windows computers, encrypting their data against their will, and asking for a Bitcoin ransom in exchange for the encryption key.   In order for such a software to run "successfully" on an OS X machine, would the user first have to run it and give the sudo password? Is such a threat conceivable on OS X without the user doing this?  Would FileVault protect against this? Could a ransomware program, if unwittingly installed by a user (who also confirmed with the sudo password), take your FileVault data hostage? Could it take hostage also your TimeMachine backups even if they are encrypted? In general, how (in)vulnerable is OS X to encryption ransomware, and how careless/unsavvy do the actions of a user have to be in order to actually have his or hers data taken hostage?


There are some abandoned PS1 oldies out there that I would love to see revamped with improved assets. I have some skills with some some modelling programs, so I was wondering if it would be possible to rip some models with or without their textures so that I could try to update them, and experience them on an emulator. Is this possible?  Even if the edited copies cannot be reinserted into the game, would it still be possible to rip the models out so that I could edit them?

Is it possible to modify Sony PlayStation 1 games?  For example I'm planning to modify a soccer game called Winning Eleven 3. What I'm exactly trying to modify is player properties such as speed, shot power and so on.


I had difficulty searching for this answer on google and debian documentation!  The FAQ page wasnt very clear either. I mean it wasnt 100% idiot-proof clear.

Say you're running a server and you don't want to upgrade to Testing (Squeeze) from Stable (Lenny) to just install a required package or two.  What's the best way of installing only certain packages from Testing?


If you go to GeoServer, layer preview, by clicking "KML" in the "Common formats" column you get a KML file that contains a URL that can be used to get all information for a layer. For example:    This is a WMS request (it contains service=WMS). I thought WMS requests only download images, but this request downloads the full data for the layer, including the coordinates of the lines (essentially the layer in vector format). I thought you'd need to use WFS for that.  The thing is that I want to permit a user to view the image of a layer (on a Leaflet map), but I don't want users to be able to download the data for the layer. I deactivated WFS for unauthorized users, but that isn't enough if they can get a KML with WMS.  What have I understood wrong? How can I fix this?

I have published a couple of layers on my Geoserver.  To be complaint with the T&C of my data provider, I need to block the access of some of those layers as Vector data. Hence I have already blocked the WFS services on these Layers.  I came to know that even on the WMS service, you can get Vector Data, if you use GeoRSS and some of the .   How do I block GeoRSS, SVG & UTFGrid as formats in the WMS Service?


I have heard from some of TV series. They are saying "suite your self", what does it mean?

I found this on SO and googled the idiom "suit yourself", but I couldn't find a matching translation. The context was that the questioner was nitpicking and the answerer lost his patience.


I have a practical visual problem.  I would like to mirror the results of the PCA. In other words, everything that is on the left should go to the right and vice-versa. In my current graph, PCA 1 (see image attached) ranges from more use of inputs (left side) to more ecological management (right side). Visually I just want to mirror the results, so everything that in on the right goes to the left and vice versa. So then, PC1 would range from more ecological management (left side) to more use of inputs (right side). It is basically turning the graph upside down, but I want a function that does that for me! Any thoughts?   I know this issue has already been theoretically covered in other topics. What I need (and can`t find somewhere else) is how to change the visual output in R?

I performed principal component analysis (PCA) with R using two different functions (prcomp and princomp) and observed that the PCA scores differed in sign. How can it be?  Consider this:  set.seed(999) prcomp(data.frame(1:10,rnorm(10)))$x              PC1        PC2  [1,] -4.508620 -0.2567655  [2,] -3.373772 -1.1369417  [3,] -2.679669  1.0903445  [4,] -1.615837  0.7108631  [5,] -0.548879  0.3093389  [6,]  0.481756  0.1639112  [7,]  1.656178 -0.9952875  [8,]  2.560345 -0.2490548  [9,]  3.508442  0.1874520 [10,]  4.520055  0.1761397  set.seed(999) princomp(data.frame(1:10,rnorm(10)))$scores          Comp.1     Comp.2  [1,]  4.508620  0.2567655  [2,]  3.373772  1.1369417  [3,]  2.679669 -1.0903445  [4,]  1.615837 -0.7108631  [5,]  0.548879 -0.3093389  [6,] -0.481756 -0.1639112  [7,] -1.656178  0.9952875  [8,] -2.560345  0.2490548  [9,] -3.508442 -0.1874520 [10,] -4.520055 -0.1761397   Why do the signs (+/-) differ for the two analyses? If I was then using principal components PC1 and PC2 as predictors in a regression, i.e. lm(y ~ PC1 + PC2), this would completely change my understanding of the effect of the two variables on y depending on which method I used! How could I then say that PC1 has e.g. a positive effect on y and PC2 has e.g. a negative effect on y?    In addition: If the sign of PCA components is meaningless, is this true for factor analysis (FA) as well? Is it acceptable to flip (reverse) the sign of individual PCA/FA component scores (or of loadings, as a column of loading matrix)?


Is there any Linq style syntax for "For each" operations?  For instance, add values based on one collection to another, already existing one:  IEnumerable<int> someValues = new List<int>() { 1, 2, 3 };  IList<int> list = new List<int>();  someValues.ForEach(x => list.Add(x + 1));   Instead of   foreach(int value in someValues) {   list.Add(value + 1); }

I'd like to do the equivalent of the following in LINQ, but I can't figure out how:  IEnumerable<Item> items = GetItems(); items.ForEach(i => i.DoStuff());   What is the real syntax?


I have two PDF files that look the same when viewed or printed, which diff says are binary and differ.  How can I find out what the differences are?  I prefer an answer that will run on Mac OS X or on OpenSUSE.

Do you know a good way to compare PDF files side-by-side and show the modifications between the two?  I'm looking for Windows software to accomplish this. It would be great if you can post both free and not-free products.


If  $X$ and $Y$ are independent random variables, then can I say that $X^2$ and $Y$ are independent?

When proving $\bar x$ and $S^2$ are independent in my noted it says that "functions of independent quantities are independent ". Can someone tell me how functions of independent quantities are independent happen?  Also let $X_1,X_2,X_3,\dots,X_n$ be a random sample.And suppose we want to estimate parameter $\theta$ using $T(x)$ as an estimator. In this I have a expression as $E\{ [  T(X)-E(T(X))][E(T(x)-\theta)]\}$.  I want to know if I can say that in $[T(X)-E(T(X))]$ since $E(T(X)$ (expected value is a one particular fixed value) and $T(X)$ are independent of one another. Also the expression $[E(T(x)-\theta)]$ is independent of $X$.  Hence the two expressions $[T(X)-E(T(X))]$ and $[E(T(x)-\theta)]$  are independent of one another. So that I can use if $a,b$ are independent $E(ab)=E(a)E(b)$ form


This question was asked in my topology quiz and I was unable to solve it and examiner don''t gave any solutions.  Question: Consider the following set of functions on $\mathbb{R}$.   A= The set of all functions on $\mathbb{R}$.  How can I prove that A has cardinality strictly greater than $\mathbb{R}$? I am unable to think of a reasoning and I will not be able to provide a attempt. Background: I have read set theory from 1st chapter of Munkres topology.

How does one compute the cardinality of the set of functions $f:\mathbb{R} \to \mathbb{R}$ (not necessarily continuous)?


If I have  in play and I want to cast , how does Ugin, the Ineffable's static ability interact with paying the cost?  Can I announce I want to cast Ugin's Conjurant for 5 and then only pay 3 mana because Ugin, the Ineffable's static abilit reads "Colorless spells you cast cost 2 less to cast"?

If I play a spell with {X} in the mana cost, and I have a card out that reduces the casting cost by 2 generic mana, what happens to the X? Does it start at -2?  For example: I have  in play. If I play  for just 1 blue mana, do we draw 2 cards?


so i'm female 18 and i was looking on a website for a sugar daddy, i started talking to one and we moved to texting, he then asked for my banking info which i turned down and asked if he used paypal. he said no and that he had been scammed threw that before so he doesn't use that anymore. after talking to him for a little i stupidly gave him my info. we had talked about amounts before and he was going to send me a couple hundred but then all of a sudden he said he was going to send me extra so that i could go buy him some gift cards and send him the codes. i said no, changed my password and told him i didn't want to be his sugar baby anymore and blocked him. he then made a new phone number and proceeded to somehow get back into my account and send me almost 1000 dollars and is now threatening me. saying that i need to go buy him some steam gift cards 450 dollars worth scratch off the back and send him the codes. i said no and told him that i would go to the police. he all of a sudden gave my a paypal email and said to send him the money back but i'm scared it'll be a fraud and it'll make my account go into the negatives. so i was stupid and panicking and i sent him 450 to get him to stop constantly calling my phone with new numbers and harassing me. i was only on the websites because my family is struggling to pay our bills. my paychecks have been going to my parents and my savings is almost wiped out because of it and im supposed to move in august.

I met a guy on a sugar daddy dating site and we talked, I told him my situation and he said he would help.   He asked for my bank account information and I told him you can use cash app or PayPal to go through. He said his account manager deals with his finances. So I set up an account with a bank that I don’t use so that my primary account isn’t used.  Eventually he was in the process of sending me money and we had agreed on a amount that wasn't crazy. But then he asked for my address and I asked why and he said just wondering. Then said he wanted to send me a surprise for being his baby. Which I didn’t give.  Then later on he sent the money and said he sent me a bonus and that I was supposed to use that to pay his mothers caregiver, which he didn’t mention until after.  I kept questioning him and he was saying that he works in construction and he’s trusting me to carry out the errand. Then he said don’t let him down and I asked him if he was threatening me and he kept saying I need this done but didn’t really answer my question.  Am I being scammed? I’m about to change my password but is this a scam?


Recently, I lost most of my drive content, and now I've succeed to retrieve my Curriculum_Vitae.pdf. I have a little problem if I want to modify this file, because I don't have the source code anymore. Is there exists a way to recover or to reload that source code from the pdf file?  Thanks for your help!

I know that hardly any information is passed to the PDF when a .tex file is compiled.  But is there a tool that can convert a PDF document back to (La)TeX?


Not as kinky as the my question suggests, but I'm trying to recall a short story I read about a couple, stranded on a planet.   If memory serves me correct, the somewhat timid wife/partner has to take medication regularly and is apparently not an intellectual match to the constantly researching male partner. Things start unraveling when she stops taking the medication though.  Turns out is that she used to be a he, and they were once colleagues on a mission together. Somehow through the drugs or some other procedure, the now husband/partner changed his colleagues sex and the medication she/he has been taking dutifully, serves to suppress any memories of her/his previous self and maintain a kind of docility in her.   I think she went back to taking the drugs after revealing that she remembered what happened, but I would love to get the title of the story and read that story again.

I'm trying to identify a short story that was probably written in the 1970s or 1980s—at least, well before today's more accepting attitude towards human sexuality and gender roles. It must have in part aimed for a shock value that has mostly dissipated today, leaving behind a sense of anger at the violation—at least in my memory.  Unfortunately, I don't recall if I read it in a magazine or an anthology. Here's what I do remember:  A woman is trying to get her domestic chores done, cooking, dishes, laundry, garden. There may be small children running around. But something is wrong. She is lonely and sad. Her husband pays no attention to her and she feels unloved. She is also very groggy, almost drugged.   Her husband tells her that she has emotional problems and that, other than her feelings, everything is fine. But as time goes on, it turns out that she is being drugged by her husband. Somehow, she finds a way to avoid the drugs without alerting him.  Spoilers below:      She realizes that she is actually a man and her "husband," perhaps a fellow crewman, has, without consent, surgically altered him with a uterus in order to bring to term frozen embryos.   As I remember it:      Their ship has crashed, with only the two of them left alive, and that their original mission had been the settlement of a habitable planet. I don't remember if they are on the same planet. Their ship had been stocked with the frozen embryos. The fellow crewman is trying to complete the mission the only way he knows how, but despises both of them as a result.     "She" realizes that her life has been changed forever and finds the only solution available to her. She drugs her fellow crewman into believing that the two of them are actually husband and wife, happily married. Thanks to WhatRoughBeast for suggesting: Her final act is to drug herself.   I'm not sure how much I got right and how much my memory has strayed, but I'm hoping there's enough here to help someone ID the story.


Prove that the diophantine equation $x^4-2(y^2)=1$ has only 2 solutions. Any hint on how to start and what to do .. I do not have a lot of experience on non linear diophantine equations and do not know how to approximate them. So far I can see that for $y=0$, $x=1$ is one solution.

The one of solution of $x^4 - 2y^2 = -1$ is $x = 1$ and $y = 1$. However, the solution $(1, 1)$  of $x^4 - 2y^2 = 1$ is failed. We know $x = 1$ and $y = 1$ is small integers and we can check by trail method. In case more solutions are existing or not how to check? What are the solutions of $x^4 - 2y^2 = 1$?


I am building a computer and installing Linux of it. I am considering of getting:  A small capacity SSD for frequently accessed files (such as the OS and programs),  A small capacity hard drive for frequently written files (such as temp files),  And a large capacity hard drive for backup, and various media (such as music and movies).  So how should I divide the subdirectories so that I can minimize wear on the SSD but keep my computer fast? Below are a couple of websites I visited, but I still need clarification. Thanks in advance, Sam.  Table 3-2 of

I have an SSD with 64 GB and a 6 GB/s 1 Terabyte hard drive. I want to use the SSD only as a boot device and maybe for swap storage. On the 1 Terabyte hard drive, I want to have the main file system. As in Windows, I liked to have at least 2-3 Partitions example for music games programs and so on. Which partition layout do you recommend to me?


Imagine I'm in a sapcecraft1 that is moving with 1.0$c$ or at least is so close to that speed that a few miles per hour would just be left to reach $c$.  So when I'm traveling now in the direction this thing moves, what would hapen? Would I forcefully be unable to move in that direction, so this thing would be like a rattrap while it is moving at that speed?  Or would I be able to catch up with bypassing lightwaves?    1This could be a planet, a man made thing a star or what ever would be most reasonable here.

Let's say I fire a bus through space at (almost) the speed of light in vacuum. If I'm inside the bus (sitting on the back seat) and I run up the aisle of the bus toward the front, does that mean I'm traveling faster than the speed of light? (Relative to Earth that I just took off from.)


My teacher told that  is $h$ and nothing more. So please explain what actually plancks constant is?

In the physics texts I have read and from other online information, I gather that  is the quantum of action or that it is a constant specifying the ratio of the energy of a particle to its frequency. However, I'm still not understanding exactly what it is?  From other things I have read, I understand that Planck did a "fit" of data concerning others' experiments and came up with this value; exactly what other data exactly did he fit to arrive at this really small value? Or maybe he did it some other way? Perhaps an answer concerning its origins will help me understand my first question better?


If we know that the virtual photon emitted in an electron scattering Feynman diagram violates the energy and momentum conservation laws (though temporarily), why do we accept it as a feasible diagram representing another perspective of reality?

I (as a middle-school student) was wondering how virtual particles even conserve energy of the entire system? I don't mean just the particle's energy, but conservation with respect to the surroundings?  Let me explain more, Einstein proved that $E = mc^2$ and equivalently, we can say $m = \frac{E}{c^2}$ . We however know mass causes curvature in space-time (gravity well). Now that statement being completely valid we can use Quantum Fluctuation, implying energy and time can be related by the relation:  $\Delta{E}\Delta{t}\approx\frac{\hbar}{2}$ and by that simple relation we can make the following points:   As the energy increases, the time allowed to be "borrowed" decreases, before it gives it back to the universe. As time increases, the energy allowed to be "borrowed" decreases.    These are completely satisfactory points I've made, I believe.  Now, I have read that the vacuum is filled with constantly bubbling virtual particles that get created from the energy "borrowed" by the above relation and is destroyed again, which satisfies the energy conservation laws.   This seems to imply that  in the short time the virtual particle exists, they must have a very small mass which is: $m_{1} = \frac{\Delta{E}}{c^2}$ and using basic classical mechanics rather than GR (for sake of simplicity) we calculate that the gravitational force mediated by this short-lived virtual particle;  $F_{g}= G\frac{m_1 * m_x}{r^2}$   where $m_x$ is an particle\mass in question. Nevertheless since we know the force set upon an object moves the object in a direction, we can say it would increase its kinetic energy by this factor: $F_g = \frac{1}{2}mv^2$ which is equal to $G\frac{m_1 * m_x}{r^2} = \frac{1}{2}mv^2$.  Surely, this implies that every time quantum fluctuations happen, energy of real-particles\masses increases and therefore violates energy conservation, but what prevents this violation from taking place?  If virtual particles are not really present and interact with objects like I thought, how can Hawking radiation (currently a large concept in black hole physics) then be accepted in physics community?


I am looking for ways to put tilde over regular text. In math mode, we can put tilde above letters by $\widetilde{ASK}$. Is there a way to do the same thing for regular text longer than three letters? I mean: not in math mode, how to do big tilde over texts? The questions being answered all require math mode.

How do I get a really wide tilde?  I need to cover at least  abcdefghijklmnopqrstuvwxyz  The \widetilde command does not work. Nor using \stackrel with \sim.


I have a new ASUS Vivobook laptop and am wondering which version of Ubuntu to install given that 18.04 LTS is scheduled for release at the end of this month.  I took a look at the  and did some research on  and see it's possible to upgrade directly from 16.04 or 17.10.  However I was wondering if installing  is perhaps an even better solution - will upgrading from the beta version to the stable version at the end of April be the easiest option?  If installing the beta version of 18.04 is not recommended, which will be a least error prone upgrade to 18.04 - 16.04 or 17.10?

I'm just a simple user frustrated with Windows 10 and I want to leave Windows altogether.  However, I don't want to spend three weeks learning how to install the new system and then get all my current programs to work.  I am not setting up a server, I am not a developer and I do not want all my stuff on a cloud.


I cant see my task bar anymore and it makes going between windows hard, how do I exit Fullscreen? I have tried F11 and Ctrl+Esc. When I change it to off in the video settings, it just makes a small window and i cant maximize it.

I accidently pressed F11 for PC minecraft and now the screen's all messed up.  When I turn Fullscreen OFF, it minimises, but the button to maximise is not working anymore.  How do I reverse it to normal?


I am working on a little project and have big problem....  I faced the bad side of NullPointerException in Java  So here is the code:    Coordinates[] point = new Coordinates[26];     for (int i = 0; i < points.length; i++) {         if (points[i] > 0) {             char ch = (char) (i + 65);                 point[i].setName(ch);                 point[i].setX(points[i]);         }     }     //Coordinates is class containing 3 fields     //setName() method just sets Name field     //setX() method sets X coordinate   I want to make point for every letter in alphabet, but I got NullpointerException when I use setName() method.How can I fix it, please help :(

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I think what I need to do is find the value of $n$ where $n^k<a^n$. I know that this value occurs whenever $n>k\log_an$, however I don't understand how to interpret this result into a general $N$ to pick as a maximum for the sequence convergence. What am I missing here?

In other words, how to prove:  For all real constants $a$ and $b$ such that $a > 1$, $$\lim_{n\to\infty}\frac{n^b}{a^n} = 0$$  I know the definition of limit but I feel that it's not enough to prove this theorem.


Just a minute ago I had to remove a virus from that folder. It was removed and I had to restart my computer because of it. It's now successfully removed but whenever I try to move or copy something to that folder, it says I need administrative permissions. Although I'm on my administrator account, whenever I click continue (with the admin icon) it still says I need administrative approval and shows the "Try again" or "Cancel" options. I can click try again so many times and it keeps popping up.

I want to use an old drive as a secondary hard drive without reformatting. But this old hard drive contains my old Vista installation which takes up gigs of space.  I tried changing ownership and it works to some extent but I can not delete anything in Windows/System32 folder.  Is there an easy way to change permissions so I can delete everything?    The solution is to use Takeown as Wil suggested and use cacls to take full control of the files. Since cacls doesn't seem to be recursive, I fired up cygwin and ran this command to recursively change all the files:  for d in $(find directory-of-interest -type d);do   cacls $d'/*' /e /G username:F; done   where directory-of-interest is in my case /cygdrive/g/Windows and username is my username.  I had to manually run it on directories that had spaces in its name. But after all this, I can now delete the directory. Warning: it seems to me that cacls can potentially royally screw things up if improperly used.


I installed Ubuntu 14.04 on my HP laptop and I formatted the partition which had Windows 8.1. So Ubuntu could have all the hard drive space. Is there a way I could uninstall Ubuntu and reinstall Windows 8.1?

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


Refraction: I want a qualitative Quantum Mechanical explanation of why do we see light rays -in the classical picture- bend when light goes from one medium to another. I read that it is due to conservation of energy and momentum, but haven't found an explanation about the reason of the change of angle. Reflection: again a qualitative explanation of why the angle of incidence is equal to the angle of reflection.    EDIT 1: what I am looking for is really an explanation about what interactions are the photons going through(like absorption and emission by molecules for example) that when we take all the photon's interactions into account give us the macroscopic picture of how light reflects and refracts.    EDIT 2: I really want an answer containing the reason for why we get the angle of incidence is equal to the angle of reflection and why the angle if refraction is as it is.

How is the following classical optics phenomenon explained in quantum electrodynamics?   Reflection and Refraction   Are they simply due to photons being absorbed and re-emitted? How do we get to Snell's law, for example, in that case?  Split by request: See the other part of this question .


How much can a power brick safely vary from what the device it's used with expects?  As an example, let's say I have a device that needs an AC=>DC power brick. The device expects 19V/1.58A, but the brick is missing. Now let's say I find a brick where the connector fits the device and is also 19V, but outputs 3.42A. How safe is this likely to be for the device? Will the device only draw the power it needs, or am I likely to blow a capacitor somewhere?  If that latter, this example the brick provides more than twice the current requested. How much closer would have I have to get to be reasonable? How much can voltage vary vs amps? Given different devices likely have more tolerances than others, is there a good rule of thumb to look for to know how much you cheat on matching power brick to device?  While the example does match a real situation, I'm also interested in the general case.

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


I have this problem:     Let $R$ a PID and $J\subseteq R$ a non-zero ideal. Prove that $R/J$ has a finite number of ideals.   I think that I must use the biyective correspondance between the ideals of $R$ that contain $J$ and the ideals of $R/J$, but I still don't see why I have a finite number of ideals that contain $J$. Can anyone give me a hint or I'm going in the wrong way?

If R was a unique factorization domain, can we deduce that for a nonzero element d in R, d has a finite number of divisors?   I need this in solving this question  "If R is a unique factorization domain then there are only finite number of distinct principal ideals that contain the ideal (d)."  My idea to solve it: if a divides d then (d) is contained in (a), so if we have finite divisors then we have finite principal ideals. Am I wrong?


I'm working on a uh60 Blackhawk. The problem is I need to give the main body a thickness. Extruding gives the object different thicknesses at different points.  I want it to have the same thickness across all of the body. So for example, I might want to have a thickness of 5cm that is maintained for the entire body.  Here is a picture of what I want to make, that needs a thickness that is maintained throughout the main body:

I'm using blender to make a basic model of my house and I want to hollow out the inside of the house so that the walls are slightly thicker and there are normals facing both ways, I'm not really sure how to can achieve this. I think it's called shelling?    Also, has anyone got any tips on working on the interior of buildings, because I find it nearly impossible to do so :/


I tried to full screen the ubuntu OS in vm box but even after installing additional files my screen had black background and it showed this error if i tried to install the additional file again. Please suggest me some solution so that i can run the ubuntu OS in fullscreen in the VM Box.

I am trying to run the command sudo mount -t vboxsf SharedUbuntuWindows SharedUbuntuWindows but I get the error unknown filesystem type 'vboxsf' on my guest Ubuntu machine. I am following  but I cannot find 'Install Guest Additions' under 'Devices'. Instead, I see 'Insert Guest Additions CD image'. Am I even on the proper path to solve the issue?    This is what I see when I select 'Insert Guest Additions CD image...'. Pressing 'Force Unmount' only makes the pop-up dialog disappear, but I still am unable to run the command sudo mount -t vboxsf SharedUbuntuWindows SharedUbuntuWindows.


In , it has been established that burning hands does indeed require touching thumbs. A question that is danced around there is, "is the touching thumbs the somatic component?" This question also extends to spells like dissonant whispers (verbal component) and message (verbal/somatic component). In other words, when a spell specifies something in its description, outside the component list, that could be nonetheless be construed as the component, is it in fact a component, or even the component? I'm inclined to think such descriptions are the component, but am unsure. This does have some weird implications if so, like "how loud does one dissonantly whisper?" and "can someone else hear my whispered message?" (I don't need these answered here; I just include them because they are related, depending on the answer.)

The  spell states, in part, that:  You speak a one-word command to a creature you can see within range.  The spell also requires a Verbal component. When I cast the command spell, is the "one-word command" the only verbal component?


All the items (both files and folders) inside my pen drive had been renamed to some characters like :]h.¡>?.A╕╗ and when I try to open any folder Windows gives this message.  The filename,directory name, or volume label syntax is incorrect  I was told that it is a problem of the pen drive, not a virus. They say if I format the pendrive then I will be able to use it again normally. But I'm not sure. And I need those files.   Does anybody knows a solution?

I opened up my flash drive this morning and all of my folders and files are normal, except for one folder and all its included files, which is the most important folder. The subfolders and files are renamed with bizarre characters and when I click to open them, a pop-up appears saying it's not accessible and the filename or directory name is incorrect. I don't want to reformat the flash drive because I'd lose all those files. Is there a way for me to restore it or something?  I would attach a screen shot, but apparently new users do not have that privilege. If you have a vague idea of what I'm talking about, let me know and I can email you screenshots so you can have a better understanding. Any help is greatly appreciated!


I am interested in installing Android 6.0 on my device Huawei Honor 7 (PLK-L01).  At this point in time, the device name is not listed in the Android website as a supported device. Would i still be able to install it?  I am really interested to understand the reasons why a certain Android-based device can't support the latest version of Android OS.  Thank you for reading my questions. Any help or explanation would be greatly appreciated.

Android "M" was officially announced on at the Google I/O conference on May 28, 2015 and revealed to be 6.0 Marshmallow on August 17, 2015.  You can review the high-level changes at the  and the announcement on the official .  Of course, not all devices will get this update right away and others won't get it at all. Each manufacturer and carrier often choose to add their custom modifications which tend to delay the official release.  When will each device get Android 6.0, either officially or unofficially, if ever?  See also:


I'd like to use HYPERLINK to add multiple links to a cell, like this:  ="Click "&HYPERLINK("google.com","here")&" or "&HYPERLINK("bing.com","here")&"."   But the above code merely results in plain text with no links at all.  Per , this doesn't seem to be a feature of Google Sheets but I'm curious whether anyone has come up with a way to accomplish this or some kind of workaround since then.

I have been frequently using concatenate to combine cells and strings to render URLs in cells. The purpose of these URLs is to open specific pages to review the information on those pages.  I am looking to create a comma separated (or other) list in one cell where I can open all of the links in separate tabs (especially if it can be in a new window).  Is there a way of using something like target="_blank to make Sheets open those links? Would it only be possible using the script editor somehow?


Is there a way to keep the checker texture the same size?  Currently it scales with the size of the object, even though the scale in the Cycles node itself is set to 5, a value of 5 looks different across the two models.   I'm pretty new to modeling so I might mess up on some terminology, but is there a node I could use -- that is universal between all objects -- that I can use to determine the size of the texture?   Or how would I make this texture consistent between the two models without manually scaling it down in the checker texture node?

Is there any way to automatically unwrap UV map proportionally to object or "world" size?  For example:  I've made two cubes, one is two times bigger than other (scale is applied). Then I unwrapped texture with Smart UV project which will try to span all faces on whole texture space(0 to 1) so bricks on left cube will be bigger than bricks on right cube.   But what I want to achieve is this:     In broader context:  When I import model from Archicad (in form of OBJ) all objects have UV's in some scale (so all bricks have the same size on every imported object). And when I want to create custom object in scene I have to manually scale UV's to adjust bricks size for every new object (instead of scaling to one constant parameter).


I've been building a unit & rate library for a forex trading algorithm and I realized I didn't have an answer to this question:  Can currencies be taken to the Nth power?  Unlike physical units, such as length or distance, the square of a currency doesn't occupy a space (I don't have much finance training so there may be theoretical properties that do).  Context:  My library is overloading operators such as $10\text{ USD } \times .98 \frac{\text{Euro}}{\text{USD}}=9.8 \text{ Euro}$. It offers currency and rate classes. If the user wants to square the true value (non unit) they can retrieve the value itself then square that. However, this library is trying to capitalize on relationships between currencies and rates. I plan on expanding it in the future, so I want a strong base. Is there a theoretical and meaningful use of a currency squared?

This is a very silly question since nobody will actually do this because it makes very little sense in the real world but I just want to know how would it actually work if possible.  For example let us take an amount of 2 dollars and 2 cents and multiply that buy 2 dollars and 2 cents. Would the result be 4 dollars and 4 cents? The only way to make sense out of this for me is to treat them as vectors and multiply components.


i fill up 4 field(Name,Phone,Course,Center) in my form. 5th field is "roll". when i fill up 4 field, then how to generate roll without form submission, i want to generate roll like that My 4 field text are below Name-Jack,Phone-1234567890,Course-Computer,Center-010 after fill up this field then generate roll and print 5th field without form submission Roll-Jac890Com10

I'm trying to create globally-unique identifiers in JavaScript.  I'm not sure what routines are available on all browsers, how "random" and seeded the built-in random number generator is, etc. The GUID / UUID should be at least 32 characters and should stay in the ASCII range to avoid trouble when passing them around.


Consider the following integral:  $$\int_{\text{One line \\ Second line}} \text{Loss}\left(\text{Foo, Bar} \vert \alpha\right)$$   which renders:    How can I have One line and Second line on two separate and consecutive lines at the bottom of the integral?

I have the following equation, where there is a lot of stuff under the sum symbol:  \begin{equation} d(\vec{x},\vec{y})=   \sum_{Z_{xy}\in\vec{Z}_{xy},\forall x\in\vec{x},\forall y\in\vec{y}}      f(Z_{xy}) \end{equation}   In the resulting document, I find it kind of hard to read. Is there a way to write the equation to make the result more readable, e.g. putting the stuff under the sum symbol on different lines?


Why does an abstract class in Java have a constructor?  What is it constructing, as we can't instantiate an abstract class?  Any thoughts?

Can an abstract class have a constructor?  If so, how can it be used and for what purposes?


I do not see the option to install Ubuntu alongside Windows in the installer.

Whenever I startup from the LinuxLive USB, and try to install Ubuntu 12.04, it only gives me two options instead of the usual 3 or 4. My options are "Replace Windows 7 with Ubuntu" and "Something Else". Whenever I go into "Something else", it looks extremely confusing. How do I install it side-by-side while using the "Something else" section? These are my partitions.   /dev/sda /dev/sda1 ntfs (104Mb, System Required Partition) /dev/sda2 ntfs (1000097Mb, Windows 7 Partition)   Or should I try reinstalling my installer on a CD rather than USB and maybe then it will have the "Install alongside" function?


I am reading through the section about pointers and arrays from "The c++ programming language", and I came across something that stumps me.     For every built-in array a and integer j within the range of a, we   have:      a[j] == *(&a[0]+j) == *(a+j) == *(j+a) == j[a]   I understand why *(&a[0]+j) means the same as a[j], because &a[0] points to the first element of a and then it's incremented by j.  I also get that *(a+j) and *(j+a) are equal to a[j], a gets implicitly converted from an array to a pointer to the first element of a, and then incremented by j and dereferenced.  But why is a[j] == j[a]?  What am I missing?

As Joel points out in , in  (aka: K & R), there is mention of this property of arrays in C: a[5] == 5[a]  Joel says that it's because of pointer arithmetic but I still don't understand. Why does a[5] == 5[a]?


I have recently been reading about Quantum Electrodynamics which I found very interesting, but even more confusing.  I understand photons mediate the electromagnetic force and interactions between charges can be described by virtual photon exchange. And that in Quantum Mechanics particles paths can be evaluated by sum over all paths...  An electron travelling from one point to another will take all paths, emitting and reabsorbing virtual photons. Does the electrons take all paths including those that involve faster than light velocities?  Is this question null, Does it mean anything to ask about properties of virtual particles?  Do I have the wrong idea about what virtual particles are?

Recently, I was reading about Hawking Radiation in A Brief History of Time. It says that at no point can all the fields be zero and so there's nothing like empty space(quantum fluctuation etc.). Now, the reason mentioned was that virtual(force-carrier) particles cannot have both a precise rate of change and a precise position(Uncertainty Principle).  So, my question is :  video says that virtual particles don't follow normal physical laws. So, how can we say that they obey the uncertainty principle?


I'm having difficulty signing up for meta.apple.stackexchange.com. When I click "signup" and choose my Google account, I'm taken back to the question without the typical flow of allowing access to Gmail info.  When I click on "comment", I'm asked to sign in with Google, but I'm immediately blocked for suspicious activity:    I don't think I've ever been blocked on the SE sites, and I know I have not offended anyone on Apple SE (yet?).  Should I be using Safari instead of Firefox? Or should I be using a different finger to press ENTER?  Or am I doing something else wrong?

I am getting this error repeatedly when I try to login to the  site for the first time using a Google id.  Sorry, your request could not be completed because it looked suspicious. If you meant to perform an action on Physics, please return to the previous page and try again.  I am using few other Stack Exchange and Stack Overflow sites,


I want to conceive a pic programmer i found this circuit but  i didn't find 1n4148 can i remplace it with 1n4001/1n4007 in  this circuit It affects the pic or dysfunction of the system in speed ou current

My PC game controller broke and since I have some old PS1 controllers I was thinking about converting one to PC. After some googling I found all I need is a parallel port plug and some 1N4148 diodes. But I live in a small town in the mountains and is not easy for me to get new components, I was wondering if the 1N4007 diodes I have could replace the 1N4148.     Reference:


How do you show that $\lim_{x\to \infty} 1-\Phi(x) \sim \phi(x)/x$? In the previous, I'm using $\Phi$ to refer to the standard normal CDF and $\phi$ to refer to the standard normal pdf. Thanks!!

$X \sim \mathcal{N}(0,1)$, then to show that for $x > 0$, $$ \mathbb{P}(X>x) \leq \frac{\exp(-x^2/2)}{x \sqrt{2 \pi}} \>. $$


I've been testing out generic programming in Java.   Here is a snippet of my code:  public class Vehicle<T extends Style> {      private T make;     private String color;     private int year;     private String brand;     private String model;      public Vehicle() {         this.brand = make.getMake();     }      public Vehicle(String c, int yr, String mod) {         this.brand = make.getMake();         this.color = c;         this.year = yr;         this.model = mod;     }      public void printInfo() {         System.out.println(this.year + " " + this.color + " " + this.brand + " " + this.model);     }      public void setColor(String c) {         this.color = c;     }     public void setYear(int yr) {         this.year = yr;     }     public void setModel(String mod) {         this.model = mod;     } }   And here is the interface Style that is being extended in the type parameter:  public interface Style {      public String getMake();     public boolean usesGas();     public boolean usesElectricity();  }   This interface is implement by another class called Ford, where the getMake() method is implement like so:  private String make = "FORD";  public String getMake() {     return make; }   In my driver class Test, I am testing all of these things like so:  public class Test{      public static void main(String[] args){         Vehicle<Ford> fordFusion = new Vehicle<Ford>();         fordFusion.setColor("GRAY");         fordFusion.setModel("FUSION");         fordFusion.setYear(2015);         fordFusion.printInfo();     } }   Now, in my understanding, one should be able to access the field variables and methods of a generic object by using an interface, which in this case is my Style interface. And the compiler has no problems with this in the IDE. The program should be accessing the getMake() method and printing out:   2015 GRAY FORD FUSION  However, the console shows:   Exception in thread "main" java.lang.NullPointerException at Vehicle.<init>(Vehicle.java:32) at Test.main(Driver.java:16)  which points to the line where I have this.brand = make.getMake();  So what in the world is going on here? What am I doing wrong?  EDIT: The question that this has been marked a duplicate of does not give a solution to my particular situation. Although the error here is a NullPointerException, it is much different than that older question.   that address the same issue as mine. If the solution to that question is valid, then I should be able to accomplish what I've been trying to do.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


What is the better option: Using su to switch to root or enabeling sudo? Without the use of sudo an intruder would need to know the password (or key) of a user allowed to ssh and then also the root password. With sudo the password of the unprivileged user would be enough.  I set up a fresh webserver (Debian 8.2) and am wondering what the best practice is to make connecting to it via SSH secure and still easy for me to work with it.  So far I have disabled PermitRootLogin on SSH and switched the port. Also iptables is in place blocking everything that I don't need. Now I have to login with an unprivileged user and then switch with  su root   But working as root isn't the best thing to do I've heard... So I thought about just granting my unprivileged user sudo rights.   Then again an intruder would only need to know one password since sudo is asking for the current users password and not for the root password. So my plan to make it harder for an attacker by disabeling PermitRootLogin in SSH isn't working anymore.  So: su root or sudo?

I have recently found an argument against disabling a root user login in Linux at   I assume that, if everybody uses a public key authentication, there's no risk at losing the root password.  Is it always better to disable the root login via ssh?


Under what circumstances can a user have an account only on (site).meta.stackexchange.com and not on (site).stackexchange.com?   And vice versa.  The thing is that I saw a user account on math.meta and it was 'complete' in the sense that it had activity and 3k reputation. Then I clicked on the main math.stack icon and it displayed a "page not found" error.  I've never witnessed this situation before. What I know is that once an account is deleted on main, it is also deleted on meta.

I found a user that have only . Trying to open main profile via  on the meta profile page gives 404 error. I don't think this is normal.  is currently banned in chat for 189 days:    Parent user link refers to already mentioned 404 page.


Currently I have something like this set up: B-R-R-R-C-R-R-R-C-R-R-R-C (etc...)  B stands for a redstone block, R stands for a repeater, and C stands for a command block.  I have a line like this (curling back once in a while, but not a loop) up to a minute -- but this method uses 120 repeaters at full delay. What circuit could I use to create something that behaves AS CLOSE AS POSSIBLE to what I have now, but taking up less space? Specifically:  1) Removing the redstone block power source won't stop the already-sent signal 2) Must have room for gradual command blocks (so at 20 seconds I could have a command block, at 30, at 35, etc...)  For specifics, this is my Deathmatch system in a vanilla Survival Games map. When the minute is over, it reaches command blocks which teleport everyone to one location. The admin in the match uses a command button in a /tellraw command to start the countdown for Deathmatch when (s)he deems it appropriate - this command sets a redstone block as the input. After it is placed, it remains placed for the rest of the game -- but I want to be able to destroy it while not stopping the minute countdown for debugging purposes. And, as it's a countdown, it needs to be able to send out a signal every second to command blocks for stuff like "15 more seconds until Deathmatch!"  Summary: I am looking for a delay as opposed to a timer. I do not want a signal that loops and am not looking for a necessarily long delay, I just want an accurate delay that is more efficient than using repeaters AND can support gradual output (IE at half delay an output, at three quarters, etc...) Hooking a timer up to an AND gate with the input won't work as far as I know (if you know a way please tell) because if the timer was half-passed when the input was given, then the "delay" would be half the intended time. And removing the input signal should NOT stop the delay from continuing. It also needs to be silent, as it is close to the surface, and non-laggy (no super-quick repeater loops).  I am asking for a very specific redstone circuit, I know.

I found 11 questions like this on gamingSE already, but none of them have proper and up-to-date answers. So I'm creating this Q&A:  How do you either activate a command x seconds/minutes/hours/… in the future or every x seconds/minutes/… in a loop?  Repeating command blocks and ticking functions execute 20 times per second, redstone is  in many situations and most of the extremely fancy solutions, like falling blocks in cobwebs, have broken over time or are needlessly complicated.


If $\mu$ is a positive measure on a measurable space $(X,\mu )$ and $f, f_n \in L^p(\mu )$ for $1<p<\infty$, are such that $f_n \rightarrow f$ pointwise a.e., show that $||f_n-f||_p\rightarrow 0$ if and only if $||f_n||_p\rightarrow ||f||_p$.  I think that for the nontrivial implication, one approach could be to show somehow that $f_n$ converges weakly to $f$ and then using the reflexivity of the space and the boundedness of the sequence to conclude. But is $L^p$ reflexive for an arbitrary measure $\mu$, or it has to be $\sigma$-finite? Also is there a more elementary solution, probably using the Vitaly convergence theorem or things like that?

Let $1\leq p < \infty$. Suppose that    $\{f_k\} \subset L^p$ (the domain here does not necessarily have to be finite),  $f_k \to f$ almost everywhere, and  $\|f_k\|_{L^p} \to \|f\|_{L^p}$.    Why is it the case that $$\|f_k - f\|_{L^p} \to 0?$$   A statement in the other direction (i.e. $\|f_k - f\|_{L^p} \to 0 \Rightarrow \|f_k\|_{L^p} \to \|f\|_{L^p}$ ) follows pretty easily and is the one that I've seen most of the time. I'm not how to show the result above though.


I am using plainnat.bst in Overleaf to generate the bibliography. But when I compile the name of the author appears first and their last name appears afterward, and it has been ordered automatically by alphabetic of last names!. As an example:     National Grid Gas.Gas Tranportation, Transmission Planning Code. NationalGrid, 2017. 92      Pratibha Gautam,  Sunil Kumar,  and Snehal Lokhandwala.   Energy-awareintelligence in megacities.  InCurrent Developments in Biotechnology andBioengineering, pages 211–238. Elsevier, 2019. 40      British Petroleum Global.  Bp statistical review of world energy june 2017.Relatório. Disponível:  . bp. com/en/global/corporate/energy-economics/statistical-review-of-world-energy. html, 2017. 15104   As you can see it is ordered by last name priority!  How can I change of priority from last name to first name? Or how can change the code to have last name first appear then name?

I want to list a company name in the author field of a bibliographic entry:  @book{CUDA,   author    = {NVIDIA Corporation},   title     = {NVIDIA CUDA Compute Unified Device Architecture Programming Guide},   publisher = {NVIDIA Corporation},   year      = {2007} }   But the entry keeps showing up "N. Corporation".  Is there a way to get the full author name to show up?  I'm currently using the siam BibTEX style.


On  a TTY ( ctrl+alt+f1 to f6 ), I use Shift+page up to scroll up and Shift+page down to scroll down. But the problem is, the scrolling is limited to certain number of lines.   How can I get unlimited scrolling on a TTY ?

I can see only limited lines on terminal by using shift+ pageup. in Ubuntu desktop version, there is option to make scroll-back lines unlimited. how to do it in Ubuntu server version. please suggest.