I want to share a folder which is on one of my drives on windows 10 with the ubuntu i've installed on virtual box.  What should i do on both of the operating systems?

I have Ubuntu installed in Virtualbox. I want to mount my VirtualBox shared folder in Ubuntu automatically when I log in Ubuntu. I put the following line in my ~./bashrc and ~/.bash_profile:  sudo mount -t vboxsf windows_share /media/windows_share   where windows_share is the name I created with Virtualbox. But everytime I start my Ubuntu, it asks me for passwd since it needs sudo. Is there anyway to automatically mount Windows share without entering password every time I log in?


Can someone please tell me which is most appropriate?  (a) "At this time, none of the parties is planning to file a motion"; or   (b) "At this time, none of the parties are planning to file a motion."

In my grammar book (English Grammar, HarperCollins Publishers), I read that none is occasionally treated as plural, but it is usually regarded as singular. Can you give me an example of sentence where none is used as plural pronoun?


I am overseas right now and purchased a new Dell laptop that was supposed to have Ubuntu installed, it has the Ubuntu sticker I was told the product does not have recovery CDs.   Anyway I am not familiar with Ubuntu and did not even know about the operating system so I asked if they could install windows 7. I found out it's not a licensed windows 7 and I have been going nuts trying to install a bunch of drivers and stuff just to get things working right, everything is running so slow.  I am wondering if them installing windows is the cause of all the driver and other problems,and if reinstalling Ubuntu will fix them? If so where do I reinstall it since I don't have a CD of the program?   Please help I am getting so frustrated. The place I got it from is not a major store just a kind of backstreet place,so I need to figure this out on my own.

I would like to see a full how-to guide on how to install Ubuntu.


I began to read the stories of Sir Arthur Conan Doyle's Sherlock Holmes, and several times already, I came across numbers the form of which surprise me...  First, in A Study in Scarlet, Chapter IV:     "Give me food," the other said, hoarsely. "I have had no time for bite or sup for eight-and-forty hours." He flung himself upon the cold meat and bread which were still lying upon the table from his host's supper, and devoured it voraciously. "Does Lucy bear up well?" he asked, when he had satisfied his hunger.   Then, in The Sign of Four, first in chapter II:     If she were seventeen at the time of her father's disappearance she must be seven-and-twenty now, — a sweet age, when youth has lost its self-consciousness and become a little sobered by experience.   Then in chapter VII:     The scent will lie upon the road in spite of their eight-and-twenty hours' start.   These numbers may also be found in some short stories, such as The Red-Headed League and The Five Orange Pips (and probably others, but I might come across spoilers if I search further...). Additionally, I also found "standard" numbers, for instance when giving time:     It was twenty-five minutes to twelve, and of course it was clear enough what was in the wind. (A Scandal in Bohemia)   ... and even when talking about age (even though my first quote of The Sign of Four uses the other form) :     All red-headed men who are sound in body and mind and above the age of twenty-one years, are eligible. (The Red-Headed League)   While I understand that these respectively mean 48, 27 and 28, I am very curious two know more about this formulation, for instance: what is specific to the time? To some writers? Is it still used? Were there rules as to when it should and shouldn't be used? Or does it depend on who's speaking, and on the context of the discussion?

19th century English texts occasionally use Germanic-style number words, such as "four-and-twenty", but the same text would also have the modern "twenty-four" in places (see e.g. Conan-Doyle for several examples).   How did the usage of germanic-style numbers change historically? When did the Germanic forms fall out of use?   (I have asked this question previously on  (German) and got a short , but would appreciate any additional input.)


I browse from a shared IP address (my university gives no other option) and I, for the first time ever, decided to answer a question on Stack Exchange.  I have apparently been answer banned but I have no deleted answers or even deleted posts.  I have a reputation of 10, not very good but surely not answer ban worthy?  I read on the FAQ question  that this might have something to do with my IP address.   Are there any workarounds other than paying for a VPN?

If you are reading this, you may have been affected by one of our post quality bans. If so, it is important that you  to understand what has happened and how to regain the permissions that you lost. While trying to ask a question, one could see:  We are no longer accepting questions from this account. See  to learn more.  Likewise, for answers:  We are no longer accepting answers from this account. See  to learn more.   Why am I getting this message? Are deleted posts taken into account too? Is a question/answer ban the same as a suspension? How do I avoid getting a question ban? How long do I have to wait before I can post again? What can I do to release the ban? How can I reactivate my account? Can I simply create a new account? I'll just ask somewhere else on the SE network, and they'll migrate my question to the correct site! Will a ban on one Stack Exchange site affect my standing on other sites in the network? Does this apply to meta sites too? My account is in good standing. Why am I still blocked?


I have changed my windows machine to Artix linux. And I had bunch of music in the windows so I just kept them in drive and moved them over to new Artix installation. At first, the permissions of files and directories was insane, everyone had execute permissions for all directories and files(because they were coming from windows). So I changed them with runnign chmod -x {dirs and files}. Because I have done all the installation and the moving the folder over as root, obviously, the owner of the files was root. So I changed them with chown -R murad rammstein (all my music is in that folder). But when I try to cd rammstein I get cd rammstein/ Permission denied. So what is the problem? The permissions and owner of the folder drw-r--r-- 9 murad wheel 4096 Jan 31 15:54 rammstein  All the other folder and files are the same, for example the directories inside of rammstein are drw-r--r-- 2 murad wheel 4096 Jan 31 15:53 rammstein-herzeleid-1995 <and 5 different folders with the same perms/owner>  And the songs' permission inside of an album folder -rw-r--r-- 1 murad wheel  9688925 Jan 31 15:53 rammstein-asche-zu-asche.mp3  From here it's obvious that I can, at least, view those folders and files. But I'm not sure a simple cd gives Permission denied error.

In my CMS, I noticed that directories need the executable bit (+x) set for the user to open them. Why is the execute permission required to read a directory, and how do directory permissions in Linux work?


Here's the description of the badge:     Zero score accepted answers: more than 10 and 25% of total   Is it possible delete my answers with positive points, and then undelete them? What will happen if delete and then undelete an accepted answer - will the "green thick" remain? Has anyone tried to cheat this way?  I won't try this but wondered if it's possible.

This is partly related to  question.  I ran some queries on odata for my work on Stack Overflow, and I have found that my statistics are the following ones:  Accepted answers: 148 Zero score accepted answers: 36 Percentage of total: 24,3%  I probably fit the idea of the Unsong hero badge, as I've mostly been active in  questions, from when it only had around 200 Questions until now.  To get the badge I could either try to get one of my accepted answers downvoted once, that would give me a 25% accept rate; I could also delete 4 of my accepted answers with 1 or more score. That would also give me the badge, but this just seems wrong: You are actually encouraging me to either try to get a down-vote on a good answer, or delete good answers.  So, should I delete good answers to receive a gold badge?  Update: It's not that I care much if I get a badge or not, it's only a badge after all and not why I spend time on Stackoverflow anyways. But it's not ideal [read: problem] that I'm encouraged to delete accepted answers or try to get downvotes to achieve a badge.


I am trying to learn android development from the beginning here. So basically it will be a calculator. The way I code the calculate function is down below:   private boolean action = false;  private String fNum;  private String sNum;  private String preOp = "=";   Action as the flag to check if there is any previous option exist. fNum and sNum as the number needs to be taken care of. fNum is the one before calculate symbol button was clicked , sNum as the number after the symbol button was clicked. preOp as the storage for the last operation.  private double Calculate(String fn, String sn){     switch (preOp) {         case "plus":             return Double.parseDouble(fn) + Double.parseDouble(sn);         case "minus":             return Double.parseDouble(fn) - Double.parseDouble(sn);         case "multiply":             return Double.parseDouble(fn) * Double.parseDouble(sn);         case "device":             return Double.parseDouble(fn) / Double.parseDouble(sn);         case "=":             return Double.parseDouble(sn);         default:             return 0;     }  }   Function to actually run the calculate.  case R.id.buttonPlus:{             if(action){                 fNum = text.getText().toString();                 text.setText("0");                 preOp = "plus";                 action = true;             }             else if (!action){                 sNum = text.getText().toString();                 text.setText(String.valueOf(Calculate(fNum, sNum)));                 preOp = "plus";             }         }break;         case R.id.buttonE:{             if(action){                 sNum = text.getText().toString();                 text.setText(String.valueOf(Calculate(fNum, sNum)));                 preOp = "=";             }         }break;   The button functions.  So I have got the error when I clicked the + button:  12-04 05:53:04.198 31194-31194/tian.secondproject E/AndroidRuntime: FATAL EXCEPTION: main     Process: tian.secondproject, PID: 31194     java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.String.trim()' on a null object reference     at java.lang.StringToReal.parseDouble(StringToReal.java:263)     at java.lang.Double.parseDouble(Double.java:301)     at tian.secondproject.MainActivity.Calculate(MainActivity.java:21)     at tian.secondproject.MainActivity.onClick(MainActivity.java:226)     at android.view.View.performClick(View.java:5198)     at android.view.View$PerformClick.run(View.java:21147)     at android.os.Handler.handleCallback(Handler.java:739)     at android.os.Handler.dispatchMessage(Handler.java:95)     at android.os.Looper.loop(Looper.java:148)     at android.app.ActivityThread.main(ActivityThread.java:5417)     at java.lang.reflect.Method.invoke(Native Method)     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)   So, am I doing it with a wrong method? or there is just some simple mistake I have made?  Thank you :)

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?


For every positive integer $n$ find $\gcd(n!+1, n+1)$.   If $n+1=p$, for some prime $p$ the answer is clearly just $n+1$, due to . However, if $n+1$ is not prime, I am stuck proving that the answer is $1$.

$(n!+1,(n+1)!)$ can be rewritten as $(n!+1,(n+1)*n!)$.  I know that if $n!$ is divisible by a prime $p$ then $p$ doesn't divide n!+1. So when I'm looking at then is $(n!+1 , n+1)$ which I can make $(n!-n,n+1)$ by  subtracting $n+1$ from $n!+1$ and since gcd is preserved in linear combinations I  still get the same gcd for $(n!-n,n+1)$. I then look at $n!-n = n[(n-1)!-1]$ again if a prime $p$ divides $n$ I'll find that $p$ doesn't divide $n+1$. So I'm looking at $((n-1)!-1,n+1)$. I've looked at the first few n's and it seems that the gcd is either 1 or n+1. But I'm stuck on how to get there from $((n-1)!-1,n+1)$.   Can anybody provide a hint as to how to proceed?


I come from C, C++, Java background. I want to create a struct/ class with some attributes and methods like:  MyClass{     string text;     array characters;     printText(){         print text;     }     printLen(){        print characters.length();     } }   So next time I can create an object like above by just calling its constructor. How do I implement this in JavaScript? I am new to the programming principles followed in javascript, I want to create a custom data type here for reusability.

I prefer to use OOP in large scale projects like the one I'm working on right now. I need to create several classes in JavaScript but, if I'm not mistaken, there are at least a couple of ways to go about doing that. What would be the syntax and why would it be done in that way?  I would like to avoid using third-party libraries - at least at first. Looking for other answers, I found the article  that discusses object-oriented programming in JavaScript. Is there a better way to do inheritance?


The Brown Bear seems to be equivalent to a fourth level character with D10 as hit dice. It has STR +4, and thanks to its 'level' a proficiency bonus of +2.  Based on those stats, its to-hit should be +6, not +5.   The often compared Dire Wolf (same level, about the same) has only STR +3, but still to-hit +5. So the proficiency bonus is not based on CR, as I first thought.  Is this a typo? Or just minor balancing applied without correcting the attributes?  Are there any official comments on this?  PS: The Brown Bear is just one example, this comes up multiple times in MM.

My question is about the basic ogre CR calculation in the monster manual, which doesn't make senses to me. I tried to make a concept of an "armored ogre" with chain mail and pikes (AC 16 and 15 (2d10+4) damage).  The problem comes when I recalculate its CR and it's exactly 2, just like the ogre. That seems odd to me because it's suppose to be a deadlier encounter! So I tried to calculate the base ogre CR.   I must be missing something because the ogre doesn't have any special defences or anything and when I calculate his CR with the Dungeon master's guide I end up with a result of 1.   If we calculate his defensive rating we start with a 1/2 CR for HP, but his AC is 2 points lower than the suggested AC, so his effective defensive rating is 1/4.  His damage rating CR is 1, but he has 2 points more attack than the suggested for his CR, so he has an effective attack CR of 2.  We end with an average between 1/2 and 1, so his final CR is 1. What am I missing?


Let $F$ be a field, with $\text{char}(F) = 0$, and $A \in M_{n\times n}(F)$ with $\text{tr}(A) = 0$. Show that there are matrices $B,C \in M_{n\times n}(F)$ that $A = BC - CB$.

The following is an interesting problem from Linear Algebra 2nd Ed - Hoffman & Kunze (3.5 Q17).   Let $W$ be the subspace spanned by the commutators of $M_{n\times n}\left(F\right)$: $$C=\left[A, B\right] = AB-BA$$  Prove that $W$ is exactly the subspace of matrices with zero trace.  Assuming this is true, one can construct $n^2 - 1$ linearly independent matrices, in particular $$[e_{i,n}, e_{n,i}]\ \text{for $1\le i\le n-1$}$$ $$[e_{i,n}, e_{j,n}]\ \text{for $i\neq j$}$$ where $e_{i,j}$ are the standard basis with $0$ entry everywhere except row $i$ column $j$ which span the space of traceless matrices.  However, I have trouble showing (or rather, believing, since this fact seems to be given) that the set of commutators form a subspace. In particular, I am having difficulty showing that the set is closed under addition. Can anyone shed some light?


I am adding Select/Option based on the user input.   How do I write a jQuery that reacts to Select/Option that is dynamically created based on user input.  Here is my jsfiddle,   I tried adding the simple jQuery to react to new Select/Option whose id is selecta. But this does not work.         // Select option for topic         $("#selecta").change(function() {         // varible to hold string         console.log("changed");         var str = "";         var val = "";         $("select option:selected").each(function() {             str += $(this).text() + " ";             val = $(this).val();         });         var divbox = document.getElementById('textbox');         divbox.innerHTML ="Selected"+ str+"";         console.log(str,val);         }).change();   Problem here :   I have a initial Select/Option and user gets to select two options. And based on this selection, new Select/Option is added to the page. I cannot figure out how can i added jQuery change trigger to this new Select/Option. Based on user's selection to this, page needs show other elements.

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I recently updated (Feb 15, 2018) my Ubuntu 16.04 from the software manager. I don't remember what programs got updated, now my taskbar & launcher is gone.  Is there a way to fix this?  I've tried everything that's available from the internet, but none works.  Will upgrading to 17.10 fix my problem? I don't want to do fresh install from the start again :(

When I login, nothing happens.   I am presented with my desktop wallpaper.    No Dash, no Launcher, nothing.


If  $A$ is a nilpotent matrix, then how to show that the matrix $I+A$ is invertible.

If $ua = au$, where $u$ is a unit and $a$ is a nilpotent, show that $u+a$ is a unit.   I've been working on this problem for an hour that I tried to construct an element $x \in R$ such that $x(u+a) = 1 = (u+a)x$. After tried several elements and manipulated $ua = au$, I still couldn't find any clue. Can anybody give me a hint?


I'm trying to animate the scroll when the same button is clicked but on different scroll areas like:  if the scroll is 0 or less than 300 px and the button is clicked, to animate the scroll to the specified element. if scrolling more than 300px, and the button is clicked, to animate the scroll to the top of the page.  But so far the first state is working but the second one, if the button is clicked will scroll to the top of the second section and not the top of the page (body).   $(window).scroll(function() {   if ($(this).scrollTop() > 300) {     // if scrolling more than 300px add classes active and up     $('#scroll-button').addClass('active up').removeClass('down');   } else {     // is no scroll or less than 300px, remove class active and add class down      $('#scroll-button').removeClass('active up').addClass('down');   } });  // is no scroll or less than 300px and #scroll-button.down is clicked, animate scrolling to the next element  $('.down').on('click', function() {   $('html,body').animate({       scrollTop: $("#second").offset().top     },     600);   return false; });  // if scrolling more than 300px and #scroll-button.up button is clicked, animate scroll to the top of the page $('.up').on('click', function() {   $('html, body').animate({     scrollTop: 0   }, 600);   return false; });
<button id="scroll-button" class="down" type="button">Click Me!</button>

Hi
    jsfiddle:


I don't know how to compute the Fourier tranform of this function:  $f(x) = \frac{\sin \pi a x}{\pi x}$  I know that $\frac{\sin \pi a x}{\pi x} = \frac{e^{i \pi a x} - e^{- i \pi a x}}{2i \pi x}$  Then I plug this function in the formula for the Fourier transform and I get:  $$\int_{\mathbb{R}}\frac{e^{i \pi a x} - e^{- i \pi a x}}{2i \pi x} e^{-i s x} dx =$$  $$= \frac{1}{2 \pi i } \int_{\mathbb{R}} \frac{e^{ix( \pi a - s)} - e^{- i x( a \pi +s)}}{x}  dx=$$  $$=\frac{1}{2 \pi i } \int_{\mathbb{R}} \frac{e^{ix( \pi a - s)}}{x} dx - \int_{\mathbb{R}} \frac{e^{- i x( a \pi +s)}}{x}  dx$$  What should I do know? We can get rid of $i$ in the exponent by changing variables, but that doesn't help much

let $K(u) = \frac{\sin(u)}{\pi u}$   show that Fourier transform of $K$ is  $ \hat{K}(\omega) = \textbf{1}_{|\omega|\leq 1} $  Some help would be appreciated


I want to dynamically set the width of a cell in a table depending on its value. I am using fowlloing code:  Helper:  if(someCondition){     var outerDivID =component.find('outerDivID');     $A.util.addClass(outerDivID , 'widthClass'); }   Markup:  <div aura:id="outerDivID" class="slds-grid">     <!-- some code --> </div>   Style:  .THIS.widthClass {     style : "width : 300px"; }   This is done to produce markup like follpwoing but for only some cases:  <div aura:id="outerDivID" class="slds-grid" style= "width : 300px">

I'm trying to hide a div dynamically. This works for me. But when I try to do a nested div. It suddenly doesnt work anymore. Am I missing something?  Component(Working)  <ui:button label="Toggle" press="{!c.toggle}"/>
Now you see me
   Component(Not Working)  <ui:button label="Toggle" press="{!c.toggle}"/>

Now you see me

   Controller  toggle : function(component, event, helper) {         var toggleText = component.find("text");         $A.util.toggleClass(toggleText, "toggle");     },   Style  .THIS.toggle {     display: none; }


I deleted "chmod" by mistake using "sudo rm chmod". What is the way to recover the chmod command? Is it 'a no way to do it' operation? I'm using Mac OS X Yosemite.

I've deleted a system file from my Mac and need to get it back.  System files can include:   hidden files in the root of / - especially unix files in /private  /System files /Library files /Applications files that ship with the core OS   System files are not any app, user files or files that can be regenerated by a known sequence such as cache files, Spotlight index files, etc…    Canonical question and answer for .


I thought by casting the value to float it would show the seconds to the tenths place.  long startTime = System.currentTimeMillis();      while (RUNNING) {         track.repaint();         // varying the x position movement         horse.setX(xpos += (int) (Math.random() * 10 + 0));         // Sleeping the thread         try {             Thread.sleep(100);         } catch (InterruptedException e) {             e.printStackTrace();         }          if (xpos >= FINISH_LINE) {                           RUNNING = false;             long endTime = System.currentTimeMillis();             JOptionPane.showMessageDialog(new JFrame(), id + " Won and took " +(float)(startTime - endTime)/1000*-1.0+ " seconds");                      }      }   instead, it is giving me way too much precision. I would like to cut it off a bit.

I need to format a decimal value into a string where I always display at lease 2 decimals and at most 4.   So for example  "34.49596" would be "34.4959"  "49.3" would be "49.30"   Can this be done using the String.format command? Or is there an easier/better way to do this in Java.


In the context of partially ordered sets, why are the words for supremum and infimum "join" and "meet"? I find the nomenclature puzzling, especially since the English words "join" and "meet" are synonyms, but denote opposite concepts when talking about posets.  Does anyone know how these concepts got these names?

I have two simple questions:   From where do the names  come from? I don't see any intuition between those names in context of order theory. From where does the notation come? I have to admit, I always had an impression that notation we use is somewhat backwards... just take the look at the picture at the wikipedia!    I used this notation a lot of times and I have to admit that often I have to stop for a minute and convince myself that I'm indeed using it right. I'm hoping that learning a bit about origin and context of name choice and notation will make it easier.


I have recently started to look more into microprocessors at the hardware level, and i am a bit confused on what are the odd-even memory locations that 8086 uses. As far as i understand, it has something to do with 8086 being a 16-bit CPU while retaining the ability to access individual bytes at a time of its 8-bit predecessor 8080, but how does it work in detail? Also, how do other early CPUs like the 68000 approach the problem of addressing individual bytes? They don't have on chip cache to read entire chunks of memory at a time nor do they have a complex MMU after all.

How does a modern CPU treat memory reads and writes on the hardware level? With old 8-bit architectures all memory locations are read and written to one byte at a time, but how do modern CPUs that have much wider data buses treat 8-bit memory? What would a modern CPU like an x86 or ARM based CPU do if it needs to read and write a value in memory which width is less than it's data bus width? AFAIK modern architectures read and write memory in chunks, so would it read and write several memory locations at a time then?


I'm trying to convert to maven, a project in Eclipse which has a lot of external jars added manually to build path.  I would like to "clean" the project and check what externals jars added are really called, either by a source or by an internal jar dependency, and avoid adding dependencies to my pom.xml which will be useless.  Is there a tool for doing this ?   Thank you if anyone has a clue.

Are there any plugins/tools available to go through the classpath of an eclipse project (or workspace) and highlight any unused jars?


I've got the next integral from a test i had.  $$\int_1^\infty\cos(x^{3/4}) \, dx$$  I had to determine whether it converges or diverges.  I've started with Taylor summations to hopefully ease it up, So: $$\int_1^\infty\cos(x^{3/4}) \, dx=\int_1^\infty\sum_{n=1}^\infty (-1)^n \frac{x^{3/2}}{(2n)!} \, dx$$  But know i don't know what to do. Anyone got a tip?

As the title says, I am unable to find a proper proof for the divergence of  $$\int_1^\infty \cos(x^{3/4})$$  As its is not positive, I can't use any of the divergence tests, nor compare it to a sum.  Opening the integral and trying to solve it is resulting in something very ugly, and I doubt that it is the right way to do it.  Could use some help, thank you.


Now this is a very basic question, might look stupid too, but I am not able to understand it. I tried to imagine what momentum really is, and it is the impact of an object. I understood how  works, but cannot understand its mathematical formulation. We all know that $p = mv$, but how does this equation work? I mean just by multiplying mass and velocity, how are we able to get this impact? Is there any derivation to this equation?

"In classical mechanics, momentum is defined as the quantity which is   conserved under global spatial translations or, alternatively, as the   generator of spatial translations."   (G.Parisi, Quantum mechanics)   From this definition (the generator of spatial translation), how can I obtain the analytical expression of the momentum (i.d. $p=mv$)?


I'm interesting is discussing and asking questions relating to various international and national standards. Is there currently, or is there any plan to create, a Stack Exchange site for standards?  Defined  Standards are conventions, whether formalised or not, for interoperation in trade, technology and other areas of human activity involving multiple people across heterogeneous environments.  Most people have heard of international standards such as the ISO 9001 Quality Assurance standard, or ISO 3166 Country and Subdivision codes. These are examples of standards published by ISO, the International Organisation for Standardisation.  Many other organisations, both public and private, also publish standards, such as the IEEE (Institute of Electrical and Electronics Engineers), the W3C (World Wide Web Consortium), and so forth.  In addition, most countries have national standards organisations, such as Standards Australia which publishes Australian national standards, and so on.  Relevance  Standards are an important part of life in technology, trade, commerce, finance, and many other areas of human activity.  The purpose of a relevant Stack Exchange community would be for members to ask questions about the existence, meaning, interpretation and implementation of specific standards which can then be answered by experts on those standards.  I believe this would be an extremely useful resource and lends itself well to the Stack Exchange community-rated question and answer format.

I have an idea or subject that should have a Q&A, and want to propose a new site. How can I do this?  Related:


My gedit got frozen for nothing while I wasn't using my computer and it seems to have problems with auto-save + stuff open from google drive via nautilus, so it saved nothing. But I simply can't lose what is unsaved there. It is too much to just remember but since was recent and my computer seemed ok, it was unsaved. So, how can I get what is there? Any method. Whatever.

I have an unsaved document opened in gedit on Xubuntu 13.10. A bug caused gedit's main window to disappear and only the title bar is still visible, reading "Untitled Document 1".  Is there a way to recover the typed text from the running but defunct session of gedit? Are "Untitled Documents" stored somewhere temporarily?


In the movie Interstellar, there's a lot of things that I don't get.   Humans, most significantly Dr Brand, were hard at work for years solving the gravity equation. Brand wanted to do something to help humans leave the Earth, he'd known for a while we were dying a slow death, and he wanted to save the species by its relocation, either with Plan A or Plan B.  The station that housed NORAD seemed to be designed to be able to take off, but why would we need the equation solved for that? Supposedly, if we never needed to come back to the Earth, we'd have a lot of fuel to burn to propel the facility out, right?  Also, how does Cooper Station tell us that we did solve gravity? It's just a huge station orbiting Saturn, so we didn't even go beyond the Solar System. So it's less than believable if we were trying to 'use' gravity to travel faster than light (I just can't see how that comes to be).  What is it, then? Were we trying to conquer time? Travel faster than light? Evolve to the beings that were shown in the movie?  The part that intrigued me the most is this dialogue:     Murph: His solution was correct. He'd had it for years.      Getty: It's worthless?      Murph: It's half the answer.      Getty: Okay, how'd you find the other half?      Murph: Out there? A black hole. But stuck here on Earth, I'm not sure you can.

In Interstellar, what do Murph and NASA do to save humanity after solving Brand's equation? Do they get the entire human race on giant space ships and transport them to a habitable planet? (How exactly do they do  this?)  If yes, is this habitable planet Edmunds' (the one that Amelia lands on)?


In my situation, I have one shell script running rsync and tar in the background. Rsync is used to transfer files, and tar is doing compression after rsync is finished. My problem is how to monitor the pid of rsync, and tells tar command to start when the pid of rsync doesn't exists anymore.  The shell script may looks like this:  rsync data.log B/ & tar data.tar.gz B/data.log &

I want to start process (eg. myCommand) and get its pid (to allow to kill it later).   I tried ps and filter by name, but I can not distinguish process by names  myCommand ps ux | awk '/<myCommand>/ {print $2}'    Because processes names are not unique.  I can run process by:  myCommand &   I found that I can get this PID by:   echo $!   Is there any simpler solution?  I would be happy to execute myCommand and get its PID as a result of one line command.


I import a model, which was made in 3ds Max. The model is missing a colored section. How can I "draw in" or recreate the white shape shown in the image?

How do you add more than one material to a mesh?   I have tried adding two materials to the object, and then assigning one of the materials to a vertex-group, but I could not find a place to assign it.  I am making a striped bouncy ball that I want to deform, so adding a different material by separating the mesh into different objects would not be ideal.


Is there any application which can let me browse different font styles and install what I have liked from Internet?

Question says it all. I need them to be available in gimp.


I have heard about the weekly newsletter. How do I subscribe?

Each Stack Exchange site has a weekly email newsletter.  What is in the newsletter? Who composes them and selects what is included? How do I subscribe and unsubscribe to a newsletter?


In Spivak's Calculus, Chapter 2, the second problem of the set asks you to find a formula for the following series:  $$\sum_{i=1}^n(2i-1)$$ and $$\sum_{i=1}^n(2i-1)^2$$ Now, for the former, this was fairly straightforward: it sums to $i^2$ and I have a proof that I'm happy with. However, for the latter, I cannot identify a pattern in terms of $n$ to begin building a proof. The series proceeds $1^2 + 3^2 + 5^2 + 7^2 + \cdots + (2n-1)^2$, so the sum for the first few indices would be $1, 10, 35,$ and $84.$ Not only have I failed to come up with an expression of this in terms of $n$, but I'm not even sure what I should be considering to lead me to such a formula.

Is there an analytical expression for the summation $$1^2+3^2+5^2+\cdots+(2n-1)^2,$$ and how do you derive it?


The above external system currently supports service hooks to send outbound messages. Is there any possibility we can connect it with salesforce. currently, I have enabled site and gave global access using @RestResource class as a guest user, But in security-wise it's a GDPR concern. What I am expecting to hear is any way we can use a username and password to achieve it?

I need to create a webhook for salesforce in data insertion from external system(chargebee) for every event that occurs in chargebee that will hit the webhook URL to send notification in salesforce. any idea how to start on it...


I want to build a convolutional neural network and train it to recognise whether the digit is 0 or 1.  Example of my training data is a 800 * 600 gray scale image containing a digit one: I have 22 such images, 11 containing zeroes, 11 containing ones.  I now build a convolutional nerual network:  def addConvolutionalLayer(layer, newDepth = None):     print(layer.get_shape().as_list())     if newDepth is None:         newDepth = layer.get_shape().as_list()[3] * 2     newLayer = Conv2D(newDepth, kernel_size = (3, 3),                 activation = 'relu', padding='same') (layer)     newLayer = Dropout(0.2) (newLayer)     return Conv2D(newDepth, kernel_size = (3, 3),         activation = 'relu', padding='same') (newLayer)  def buildModel():     s = Input((600, 800, 1))     d1 = addConvolutionalLayer(s, 32)     d2 = addConvolutionalLayer(MaxPooling2D(4)(d1))     d3 = addConvolutionalLayer(MaxPooling2D(4)(d2))     d4 = addConvolutionalLayer(MaxPooling2D(4)(d3))     f = Flatten()(d4)     dense = Dense(64, activation='relu') (f)     o = Dense(1, activation='sigmoid') (dense)     model = Model(inputs = [s], outputs = [o])     model.compile(optimizer='adam', loss='binary_crossentropy',               metrics=['accuracy'])     return model  model = buildModel() model.compile(optimizer='adam',         loss='binary_crossentropy',         metrics=['accuracy'])   In short, a network consists of multiple convolutional layers (with MaxPooling included), ending with a dense layer.  I then split the data into training and test sets:  X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3)   X_train, X_test are arrays of float values, each value corresponding to the pixel in the image (1.0 for white, 0.0 for black).  y_train, y_test are lists containing 0 or 1 depending on the digit in the corresponding image.  Finally, I run the model to train:  model.fit(X_train, y_train, epochs = 50, validation_split=0.2) model.save('prediction.h5')   The problem is that the model gets over-fitted: it reaches 100% accuracy on the training data, but does not perform well on the validation set:  Epoch 95/100 12/12 [==============================] - 0s 32ms/step - loss: 1.0640e-07 -     acc: 1.0000 - val_loss: 10.7454 - val_acc: 0.3333   How to fix this issue?

I'm training a neural network and the training loss decreases, but the validation loss doesn't, or it decreases much less than what I would expect, based on references or experiments with very similar architectures and data. How can I fix this?    As for question        to which this question is inspired, the question is intentionally left general so that other questions about how to reduce the generalization error of a neural network down to a level which has been proved to be attainable, can be closed as duplicates of this one.  See also dedicated thread on Meta:


I'm looking for a method to stop a given list of websites from appearing in my Google search results. Any chance I can achieve this?

How do I prevent links to a particular website from showing in search results on chrome, on my mobile?  For example I want to see a video of maybe cows dancing  But I don't want to see any links related to dailymotion.com.  Is there any way I can filter those results out?  (If this doesn't belong here, please leave a comment as to where I can ask this. I feel this could be helpful for others too so I asked it here)


Let $(u_n)$ be a sequence of real numbers with the following property \begin{eqnarray*} \forall\,m,n\ge1,\quad u_{m+n}\le \frac{m}{m+n}u_m+\frac{n}{m+n}u_n \end{eqnarray*} Is it true that $(u_n)$ converges to $\inf u_n$ which is either $-\infty$ or a finite $u\in\mathbb{R}$? There's no obvious monotonicity property that I was able to use. It's not hard to see that $u_{2n}\le u_n$, but I was unable to make any use of it. My attempts to show that $(u_n)$ is Cauchy were not successful. Neither was my attempt to prove that $(u_{2n})$ and $(u_{2n+1})$ are convergent. Any hints would be appreciated.

Let $\{ a_n, n\geq 1\}$ be a sub-additive sequence, i.e. for any $m,p\geq 1$ $$ a_{m+p} \leq a_m + a_p. $$ .Prove that $$\lim_{n\to\infty} \frac{a_n}{n} = \inf_n \frac{a_n}{n}.$$ I guess the first step is to state $$a_{n} = a_{mp+q} \leq a_{mp} + a_q$$ but I'm not sure where to go from here....


Still trying to wrap a property into my Addon where I can dynamically control the values of the resulting variable.  Take the default operator_mesh_add example and alter the  definition of the width FloatProperty to be:   def get_func(self):     print('get_')     return self.actual_width  def set_func(self, value):     print('set_')     self.actual_width = value  class AddBox(bpy.types.Operator):     """Add a simple box mesh"""     bl_idname = "mesh.primitive_box_add"     bl_label = "Add Box"     bl_options = {'REGISTER', 'UNDO'}      actual_width: 1.0      width: FloatProperty(         name="Width",         description="Box Width",         min=0.01, max=100.0,         default=1.0,         set=set_func,         get=get_func,     )   this gives:   AttributeError: 'MESH_OT_primitive_box_add' object has no attribute 'actual_width'   if the get/set functions access the self.width member, there is an infinite recursion.  We really need a tangible example of how to use get/set within an operator setting.  Following  and making set/get:  def get_func(self):     print('get_')     return self['width']  def set_func(self, value):     print('set_')     self['width'] = value   results in:  KeyError: 'bpy_struct[key]: key "width" not found'   What is the right way?

Here is my test code and picture:  import bpy   # Simple property reading/writing from ID properties. # This is what the RNA would do internally. def get_float(self):     return self["testprop"]   def set_float(self, value):     self["testprop"] = value  #bpy.types.Scene.test_float = bpy.props.FloatProperty(get=get_float,set=set_float) bpy.types.Scene.test_float = bpy.props.FloatProperty()   bpy.context.scene.test_float = 12.34     When I don't explicitly set the "get/set" function for my property, after assigning the value, I can get the property value by 'scene["test_float"]', but if I explicitly set the "get/set" function, then if I try to type in the same commands, I will receive a error "KeyError: 'bpy_struct[key]: key "test_float" not found'" . So what should I do to get the same results by using explicitly  "get/set" function?


Let's say you have a 10 solar mass BH and dump 10 solar masses of antimatter into the BH... What would happen?  Would I have a 20 solar mass BH? Would the BH explode  Do we even understand what would happen to antimatter in the BH?

Let's say a black hole of mass $M$ and a very compact lump of anti-matter () also of mass $M$ are traveling toward each other. What does an outside observer see when they meet?  Will they blow themselves apart in a  matter/anti-matter reaction? Or will their masses combine, never quite meeting in the infinite time dilation at the event horizon?


I'm trying to typeset the following (the part in green I'd like to add, but don't know how to:    Here's my sample code:  \documentclass{article} \begin{document} $$=F_j\underbrace{\frac{\partial G_j}{\partial x_i}}_{\substack{\text{derivative} \\ \text{acts} \\ \text{only} \\ \text{on} \: \vec G} }-F_j\frac{\partial G_j}{\partial a_j}$$ \end{document}   Any ideas?

There is a part of my paper where I use the distributive property and it might not be clear to the reader to see the operation result (I'm using in proposional logic for a proof). The logic equation (part of) is: $$ (l_{1}) \vee \big( (p \vee q) \wedge (\neg p \vee q) \wedge (p \vee \neg q) \wedge (\neg p \vee \neg q)\big) $$ $$ (l_{1} \vee p \vee q) \wedge (l_{1} \vee \neg p \vee q) \wedge (l_{1} \vee p \vee \neg q) \wedge (l_{1} \vee \neg p \vee \neg q) $$  So I was wondering if there is a way to represent this operation like a 'shower' (see another example in pic ). Maybe there is some hidden magic mathmode command or pkg for this. At last we can also rely on tikz.


When I am downloading the application from the Play Store, I am getting this message.    "Error while downloading <application_name>. There is insufficient space on the device"   I am using Sony Xperia C and I have sufficient space in the internal memory and in the memory card. This message is cracking my brain as it is shown for the application under 2 mb and I have almost half GB free. I am not able to update the applications too.   Please help me to solve this issue. I am using android 4.2.2.

After one of the latest updates (not sure if it was the last one or a previous one) of the Google Play app, I am having an error trying to update a large app (42MB). It says:     Error Downloading . There is insufficient space on the device.   My device is a Samsung P1000 running Froyo. It's rooted, but the error was there before rooting it.  A quick Google search showed several Samsung users having the same problem (the app in question that was giving me the headache is Smurf's village). Some said that removing the updates to the Android Market (Google Play) app would fix it, but to me it was of no avail.  I also tried the procedure in  to no avail.  Now I am stuck with a prehistoric version of the Market (that works on small apps) and still cannot update Smurf's Village or install big apps. How can I fix this?  EDIT: device has over 2GB of internal SD storage, 27GB of external SD card, so space is not an issue.


I have a problem with an exercise regarding an application of the open mapping theorem.      Let $U$ be a domain and $f: U \to \mathbb{C}$. Let $K \subset U$  be a connected compact set with non-empty-interior, such that $|f(z)|$ is constant along $\partial K$. Show that $f$ either has a zero in int($K$) or is constant.     I tried to solve this by contradiction. Suppose that the claim is false. Then $f$ has no zeros in int($K$) and is not constant. Because $K$ is compact it is bounded. If I can show that $K$ is open then $K$ is a domain and I can conclude that $|f|$  attains its maximum and minimum on $\partial K$. Because $f$ is constant on $\partial K$ it follows that $f$ is constant on the whole of $K$. This implies that $f(K)$ lies in the interior of a circle. Because $K$ is a domain and $f$ is holomorphic and not constant it follows from the open mapping theorem that $f(K)$ is a domain and therefore open in $\mathbb{C}$. But the interior of the circle containing $f(K)$ is empty so we get a contradiction.   The issue is that this argument rests on the idea that $K$ is a domain. In order for this to be true I have to show that $K$ is open in $\mathbb{C}$. Unfortunately I don’t see how to prove this.

I am struggling with the following exercise:  Let $G \subseteq \mathbb{C}$ be a domain and let $K \subset G$ be compact with non-empty interior. Let further be $f: G \rightarrow \mathbb{C}$ a holomorphic and non-constant function with $\lvert f(z) \rvert = C$ for all $z \in \partial K$ and some constant $C \in \mathbb{R}$. Show that $f$ must have zeroes in $K$.  My idea is this: I think it should be true that the the maximum value of $f$ on $K$ has to be on the boundary of $f(K)$ and is due to our assumption equal to $C$. So the disk centered at $0$ with radius $C$ should contain $K$. All the values of $f$ in the interior of this disk have to be smaller than $C$ , however. I guess that we may now conclude that $f$ has to be equal to $0$ for some point in $K$. Could you tell me if I am on the right track?


I'm in need of the Boar Skin resource, and am wondering if I can purchase it from a merchant, and if so which one in particular?  Or do I have to roam the wilds randomly killing boars until one drops this resource?

I'm looking to upgrade all my pouches, but some animals are hard to find, or the part needed drops rarely.  Is there a merchant somewhere that sells them outright? I have shards to spare.


Let postive integer $n$ is not a power of a prime. Prove that $$\sum_{1\le k\le n-1,\gcd{(k,n)}=1}k=\dfrac{1}{2}n\varphi{(n)}\tag{1}$$ where $\varphi{(n)}$ is the Euler totient function  I kown $$\sum_{1\le k\le n-1,\gcd{(k,n)}=1}=\varphi{(n)}$$But I can't prove question $(1)$

could any one tell me how to find the sum of all positive integers less than $n$ and relatively prime to $n$? $n>1$  For $n=7$, I have  $\phi(n)=6$ and  the sum is ${6(6+1)\over 2}={n\over 2}.\phi(n)$, is that true for any $n$?


What I'm basically asking is that if a body is projected with sufficiently high velocity so that it doesn't escape from the earth's gravitational field but reaches an appreciable height with respect to the radius of the earth, then when it comes back will it land on the same spot from which it was fired?  You can neglect drag force and winds but do consider the rotation of the earth.   Basically what has to be considered is that the net force acts towards the centre of the earth and so I tried conserving angular momentum. That shows that the angular velocity of the object will decrease with increasing height above the earth. So basically the object moves with smaller angular velocity for some time in it's path.   That led me to believe that when the object finally lands back on earth it wouldn't do so at the place from which it was projected. Am I wrong?

If I'm standing at the equator, jump, and land 1 second later, the  Earth does NOT move 1000mph (or .28 miles per second) relative to me,  since my velocity while jumping is also 1000mph.   However, the Earth is moving in a circle (albeit a very large one),  while I, while jumping, am moving in a straight line.   How much do I move relative to my starting point because of this? I  realize it will be a miniscule amount, and not noticeable in practise,  but I'd be interested in the theoretical answer.


I'm working on proving the following:   If $P:V\to V$ is a linear operator and $P^2=P$ and $\|Pv\|\le\|v\|$ for all $v \in V$ then $P$ is an orthogonal projection.   My thoughts on this are that a linear map with the following properties is an orhtogonal projection: $null(P) $ is the orthogonal complement of its range, $P^2 = P$ and $\|Pv\|\le\|v\|$.  Therefore it should be enough to show that the range of $P$ is orthogonal to its null space. How to do this? Let $n \in null(P)$ and $u \in range(P) = U$. Want to show: $\langle u,n \rangle = 0$.  Am I doing this right? And how can I show $\langle u,n \rangle = 0$?

Seems like I , I think I am missing something important.     Let $V$ be an $n$ dimensional inner product space ($n \geq 1$), and $T\colon\mathbf{V}\to\mathbf{V}$ be a linear transformation such that:         $T^2 = T$   $||T(a)|| \leq ||a||$ for every vector $a$ in $\mathbf{V}$;         Prove that a subspace $U \subseteq V$ exist, such that $T$ is the orthogonal projection on $U$.   Now, I know these things:   The fact hat $T^2 = T$ guarantees that $T$ is indeed a projection, so I need to prove that T is an orthogonal projection (I guess this is where $||T(a)|| \leq ||a||$ kicks in). To do this I can prove that:   For every $v$ in $ImT^{\perp}$, $T(v) = 0$ Alternatively, I can prove that for every $v$ in $ImT$ and $u$ in $KerT$, $(v,u)=0$. $T$ is  (according to Wikipedia) The matrix $A = [T]_{E}$ when $E$ is an orthonormal basis, is hermitian (this is equivalent to the previous point). What else?    I've been thinking about it for quite some time now, and I'm pretty sure there is something big I'm missing, again. I just don't know how to use the data to prove any of these things.  Thanks!


How can i perform code review with coder_review command in a specified folder? I see that i can give it contrib or core directives, but i would like to only check a folder in my modules folder like  /modules/dev  /modules/contrib/  /modules/custom/  How should i instruct coder-review command to check those modules (custom) only?  Tried drush coder-review <folder-path> that doesnt seem to work, is there any other option, or should i patch the module to accept my 'custom' directive?

I have unsuccessfully attempted to find how to use the Coder module with Drush. Does anyone know how should I use it?


My current method of rounding to x decimal places:  public static float roundInc(float value, float increment) {     float inc = 1f / increment;     return Math.round(value * inc) / inc; }   Which works fine for certain numbers, but seems to break, and I can't seem to figure this out.  I pass through the value 2.109375 Output of the function returns 2.11 Then I add that to 5.0 (is also a float, stored in a float array (float[])), and for some bizarre reason, adding the 2.11 + 5.0 returns 7.1099997...  Can someone explain this? Cause as far as I can see, after printing the two 2.11, and 5.0, showing those two exact values, then added together breaks everything...

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


A word for someone who refuses to admit to being wrong or mistaken about anything, even as minor as a typo?

Is there a word for someone that always has to be right? The person gets angry if they are not.


I was just trying to set up a small example program in .net core c# but always run into a problem with the setter and getter        public int wheels {                 get { return wheels;}                 set {  wheels = value + 10; }                 }   Exception has occurred. An unhandled exception of type 'System.StackOverflowException' occurred in core_app.dll  I mean, this is the way how you use it, right? When I just write set; get; it is working without any problem.

I know java and would normally put in getter/setter methods. I am interested in doing it in C# with the following code, but it throws a StackOverflow exception. What am I doing wrong?  Calling Code  c.firstName = "a";   Property Code    public String firstName; {     get     {         return firstName;     }     set     {         firstName = value;     } }


Can Ubuntu 16.04 be installed on a Macbook Pro (Retina, 13 inch,early 2015)

I am a bit financially strapped and received a Gateway GT5056 tower. The tower has an AMD dual core 64-bit processor in it. Will Ubuntu 12.04 run on this machine? I will not have any other application other than LibreOffice installed.


I met guys online as sugar daddies without sugar. I have never given my bank password but some guys request that I buy Google Play gift cards and I answered I wouldn’t use my cash for it. The guy said      I would be sending your allowance from my bitcoin wallet baby... so whenever I send you your allowance I would also send you some more money so you can get me Google Play cards with them so I can invest in my Bitcoin wallet account and I would be able to spoil you more baby... remember you will be getting the Google Play cards with my money not yours   And other said     I’m gonna write you a check of 2000 babe you can hold 500 I want you to please help me to make an w transfer to one of my friend there babe   He asked me transfer to his co worker. It sounds strange. Are these scams?

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?


I had a big mistake  I run this command on a centos 6.8 server:  chmod 0644 -R /* instead of chmod 0644 -R ./*   now directory listing on root directory / and all files failed when I run this command:   chmod 0775 -R /*   I get this error:   bash: /bin/chmod: Permission denied   how can I fix it without reinstall my centos?

This is a  about File Permission and Why 777 is "destructive".   I'm not asking how to fix this problem, as there are a ton of references of that already on Server Fault (reinstall OS). Why does it do anything destructive at all?  If you've ever ran this command you pretty much immediately destroy your operating system. I'm not clear why removing restrictions has any impact on existing processes. For example, if I don't have read access to something and after a quick mistype in the terminal suddenly I now have access well... why does that cause Linux to break?


So, I am planning to buy HUION K58 which is a pen drawing interface graphics-surface.     I just want to know does it work with Ubuntu 14.04 LTS without very much tricks? I searched google but I did not find anyone with this problem.

With the announcement of the Ubuntu Phone OS I'd like to know what phone (and tablet) models are supported at this time.  Note from foss & Oli: We are making this the master question for all future "Will this work on <insert random tablet/phone/device here>?!" questions


I have a matrix and want to reference several nodes of this matrix. How do I add a line for some of the cells?  I came up with this:  \documentclass[12pt]{scrbook} \usepackage{tikz} \usetikzlibrary{matrix}  \begin{document} \begin{tikzpicture}         \matrix (m) [matrix of nodes]         {1 & 2 & 3 & 4 & 5 \\};          \foreach \i in {0, 3}         {                 \pgfmathsetmacro\iplusone{1+\i}                 \pgfmathsetmacro\itimesfour{4*\i}                 \draw (m-1-\iplusone .south) -- node [at end] {\itimesfour} +(0, -1);         }; \end{tikzpicture} \end{document}   Which is a simplified version of what I want to do. However, this does not work and gives the error:  Package PGF Math Error: Unknown operator `s' or `so' (in '0.south').   I don't know where to start with this error at hand.

I have the following code:  \documentclass[11pt]{article} \usepackage[a4paper]{geometry} \usepackage[utf8]{inputenc} \usepackage[english]{babel} \usepackage{tikz} \usetikzlibrary{positioning} \begin{document} \begin{tikzpicture}[node distance = 0.5cm, auto] \node (0) {Block 0}; \node (1) [below= of 0.south] {Block 1}; \node (2) [below= of 1.south] {Block 2}; \end{tikzpicture} \end{document}   It prints this:    I tried to do the same with pgf loop, but don't know how to decrease the counter:  \foreach \x in {0,...,2} {   \ifnum\x=0\relax       \node (\x) {Block \x};   \else       %\prev=\x - 1 <- ???       \node (\x) [below= of \prev.south] {Block \x};   \fi }


During stimulated emission in laser,the electron de-excites by supplying energy,generally it must excite,right? My doubt is then why does it de-excites?

I'm studying a chapter about atomic physics right now but there's thing I just don't seem to understand. When stimulated emission occurs, there's an incoming photon which stimulates the atom to go an energy level lower with the result that a new photon gets emitted.  Can someone explain the reason why the incoming photon stimulates the atom to emit a second one? To me it seemed more logic for the atom to absorb the photon and go an energy level up. There seems to be a phenomenon which I don't know about.


My daughter is 13 years old almost 14 and is obsessed to the point she is addicted to becoming a furry. At first I thought it was harmless when she was younger and thought it was just a little phase. After getting contradictory information via internet and actually seeing videos being sexually suggestive - made me start to shut this idea down. She would stay in her room hours on end and just pretend and dress up as an animal while recording herself. My daughter has a very low self esteem and not sure why, she’s a beautiful girl. She doesn’t have many friends and struggles to make bonds. I have seen attempts at friendships but hasnt made a real connection with anyone from school. She doesn’t have much self confidence but feels like she does hiding behind a mask and pretending to be a dinosaur. Everyday I’m still making her brush her hair brush her teeth shower. She is not concerned with good hygiene. I’ve told her if she just put half the effort she did in being a furry into herself in real life her self confidence would flourish. She just recently received her phone back after months of not having it (during which I never heard anything about furries anymore) and just recently made a friend who she seems to connect with. Today the furry conversation came about along with an hour long discussion about why I don’t agree with it and her begging and throwing a tantrum. These are my concerns  1) She already doesn’t have self confidence. Being young I think she may regret when she’s older, looking back and still being bullied for choices she made while she is younger. 2) She carries the behavior on in high school and is bullied - and goes deeper into feeling awful about herself resulting into something that would devastate our family 3) Her obsession and willingness to trade everything else such as her gaming console and her cell phone. I feel that if the obsession is that great it is an addiction and seems unhealthy. 4) I want her to build self confidence in her REAL life not hide behind a animal mask for acceptance of strangers on the internet. 5) Exposure to the side of it that’s not appropriate  I’m at a lose as to how to handle this anymore.

My 13 year old step-son told his mother yesterday that he wants to be a "."   A couple days ago he decided he wanted to make a cat costume. I just shake my head most of the time when he comes up with these ideas and try to remind him he's 13 now and that might not be the priority at the moment (like saving for a car and other teen boy interests). He has ADHD, so his personality is that of a very sensitive and slightly immature nature.  He ended up making his costume and wearing it to school. I didn't know this until after the fact. But his mother (my wife) said that while no one laughed or made fun of him in front of him there was probably some talk behind his back. It is a very small school in a very rural part of the US.  This prompted my wife to have him Google what a "furry" is and after doing so discussing it a bit further on his feelings about that topic. I'm sure the whole concept was introduced to him from spending too much time on YouTube and coming across things which may seem innocent but have longer term effects or other connotations attached to them.  He said he wanted to do this "because he can be who he is." I think the whole thing was pretty innocent but a bit off for a 13 y/o. After the later discussion he expressed that the costuming and what-not would just be a hobby for him, that its not some kind of lifestyle change or related to fetishism.   I'm concerned for a number of reasons. While I struggle with the idea, I worry more for him dealing with it all. I don't see his bio-father taking it well nor his maternal grandfather. Maybe that won't be a big deal if its only a costume making hobby. Should it be a regular thing to wear to school, etc., I see problems. Being in a small town, yet big enough for weirdos as it is, people are very judgmental.   My Question is this:   What should I do? How can we be supportive of him in his choices without him being bullied? Do we help him embrace this or try to deter him away from it? Are we over-thinking this at this point in time?


I am citing 2 papers from the same authors. I read that LaTeX puts a dash if the authors are the same. How do I remove that dash and still put in all the authors name like usual?  @article{resnet,     author  = "Kaiming He and Xiangyu Zhang and Shaoqing Ren and Jian Sun",     title   = "Deep Residual Learning for Image Recognition",     year    = "2015",     journal = "ArXiv" }  @article{heinitialization,     author  = "Kaiming He and Xiangyu Zhang and Shaoqing Ren and Jian Sun",     title   = "Delving Deep into Rectifiers: Surpassing Human-Level Performance on ImageNet Classification",     year    = "2014",     journal = "ArXiv" }     \clearpage \section*{References} \bibliographystyle{IEEEtran} \bibliography{refs.bib}   i add the function \usepackage[style=ieee,dashed=false]{biblatex} but my references become the refs.bib

In my .bib file, I have two entries with exactly the same author names:  @article{Seshadrinathan2010A-Subjective-St,     Author = {K. Seshadrinathan and R. Soundararajan and A. C. Bovik and L. K. Cormack}, ....  @article{Seshadrinathan2009Study-of-Subjec,     Author = {K. Seshadrinathan and R. Soundararajan and A. C. Bovik and L. K. Cormack}, ....   When cited after each other, and typeset with the IEEEtran bibliography style, the .bbl file reads:  \bibitem{Seshadrinathan2010A-Subjective-St} K.~Seshadrinathan, R.~Soundararajan, A.~C. Bovik, and L.~K. Cormack, ``A   subjective study to evaluate video quality assessment algorithms,''   \emph{SPIE Proceedings Human Vision and Electronic Imaging}, 2010.  \bibitem{Seshadrinathan2009Study-of-Subjec} ------, ``Study of subjective and objective quality assessment of video,''   \emph{IEEE Transactions on Image Processing}, 2009.   As you can see, the author names have been replaced with ------. It looks like this in the final PDF:    Is this normal behavior?


If a code portion of an answer is not formatted correctly and I edit it, it is not considered a valid edit unless I change 6 characters. But what if I only want to update the format of the answer and not change the answer itself.

On Stack Overflow, there was a question with an incorrectly formatted list, which lacked a newline before it and thus came out like this: 1. Hello 2. Something else 3. Goodbye  I changed it to the right formatting by inserting a newline:   Hello Something else Goodbye   And I got the "Edits must be at least 6 characters" error message. Is there an OK way to trick this rule?


I have a problem one of the users who asked awhile ago about something related to SQL injection. I provided an answer for his problem, and some solutions, but he did not accept my answer nor did he accept any other users' answers. Yesterday, someone opened a bounty on that question, to give my answer there some respect (it's really a good answer).    I want to know if I can be awarded that 500 pt. bounty even though the asker has not accepted my answer.

It's possible to offer and award bounties of reputation on questions.   What is a bounty? How can I find questions that have a bounty attached? How do I start a bounty? When can I start a bounty? Why is the system requiring me to choose a bounty amount that's higher than the minimum? Can I use Markdown formatting in the bounty remarks? Can I edit the remark? How long is the bounty period? How do I award a bounty? Can I award a bounty to my own answer? Can I award a bounty to an old answer? If I offer a bounty on someone else's question, can I award the bounty to their answer? After awarding the bounty, can I remove it or move it to another answer at a later time? What happens if there's no answer after the bounty period? What happens if I feel my question is still unanswered? What is automatic awarding? Are bounty awards exempt from the 200 points/day reputation limit? How does Community Wiki mode affect bounties? How does user deletion or post dissociation affect bounties? Can I award a bounty to an answer from a deleted user or one where the author was dissociated? Can I offer a second bounty after the first one has expired? Can I raise my bounty? What happens if a bounty question is closed or deleted? Why can't I vote to close or migrate a bounty question? What happens if I delete my account while I have an active bounty? Do I keep an awarded bounty when I delete my answer? What happens if a question where I awarded a bounty later gets deleted or migrated? Can I cancel my bounty? Can I affect / divide / share part of my bounty to two (or more) users? How many outstanding bounties can a single user have?      See also:  in the Help Center


Dose any one have example (picture) of real pcb board of various size traces .like 40th 60th....etc.actually i designed pcb on software as my term assignment .but i want to which width looks like how in real life ..i have also seen 3d simulation but i'm not satisfy with that .so that i want to see a real life example  like a picture of a pcb .If any one have any example then please give it to me .it will help me a lot

Is there a standard for the sizes of PCB traces?  That is are some 25 mil and others 10 mil or is can you choose your own?  I plan to run 400mA through some thicker traces, but less than 30mA for all other traces. About what size would I need?


my friend broke his iPhone 4S digitizer in very unhappy way. He didn't have backup or synced computers and he had cellular data turn off.  I successfully replaced digitizer and turn on the iPhone. Whow! Your iPhone is disabled for 47 years. Okay, so normally after battery replacement iPhone time is flushed and after reboot new time is fetched over NTP via cellular data, synced PC or already signed Wi-Fi. Not working in this case..  So theoretically there are two possible solutions:   Somehow fetch or rewrite correct clock's value Mount NAND flash drive, export keys from CPU, merge it with passcode, decrypt data   Any advice or experiences?  Thanks!

After the screen was replaced on my iPhone 4S, I a got "disabled for 24+ millions minutes" text on my screen due to battery being unplugged. Unfortunately I have disabled cellular data and I wasn't connected to any Wi-Fi network. Is possible to unlock my iPhone without erasing data? I know the device's passcode.


Why didn't I get the Mortarboard badge again even though I achieved 227 in a single day (18-01-2018)?  Removing the tag wiki of 4, it still stands at 223.    Yes, I have gone through the discussion . But the scenario in that question is totally different.

Formerly List of all badges with full descriptions.  What are badge name's requirements? Why didn't I get badge name ? Which badges can I earn multiple times?    Jump to:                    Note: Some badges are awarded based on score. The term score means the total number of upvotes minus the total number of downvotes.  Any badge with a *** next to it is one of 20 badges that count towards the  displayed on a moderator candidate in an election. The candidate score is a total of 40 points: the first 20 are awarded based on the user's rep divided by 1000 and rounded down; the second 20 represents the total number of unique badges earned of the 20 that count. Note that if the same badge is earned multiple times, it will only count once towards the candidate score.  Any badge with a "(retired)" next to it is no longer awarded, but is retained by users who previously earned them. See  for more info on what it means for a badge to be retired.       Visit the  of the  on any site to see a complete list of badges that you can filter by earned, unearned, or type.


Sometimes it is difficult to tell whether or not an answer (especially for first post users) has already been addressed by previous answers. An example here:    Here I am reviewing a user's first post.   It seems to simply answer the question asked. However, when navigating to that very same question...    As you can see, the currently accepted answer to that question has already listed what this new answer has, so this post brings nothing to the table. That said, for a person who has just been granted privileges to use the review queue, they may not be as able to understand the context within the question and its answers and could have trouble determining if this was a legitimate answer.  Could it be possible to at least add some context from the question to the review reading pane?

when I am reviewing an answer, I only see the answer to be reviewed and the corresponding question.   If the answer actually answers the question - at least to some extent - then I have to look at other answers to see if it is not a duplicate. This is sometimes problematic, especially when using a smartphone...    For convenience, I would suggest one of the following:    Show all the answers in review mode,  Introduce a "show other answers" button,  Show at least accepted answer - if any.     (The last option would not quite solve the problem, though)


I am trying to generate bulk emails through SAS, based on instructions of  by Eric Tilanus.  I cannot put a line break and all the put statement products appear in the same line in the email body.  I am using SAS 9.4. Sample code is below.  Do you know how I can get a line break?  data _null_;     length body $1024;     set DSIN end=last;  file outbox;      put '!EM_TO!' email;      firstLine= catx(' ',"first line",put(dttm,datetime19.), "blah");     put firstLine;      /* how can I get a line break here? */      put "second line";      put '!EM_SEND!';     put '!EM_NEWMSG!'; if last then put '!EM_ABORT!'; run;   Here is the email body generated:  first line 06JUL2015:21:25:40 blah second line   UPDATE:  has useful info. Outlook truncates line breaks. Putting two spaces before the string bypasses Outlook's automatic line break truncation.

I'm sending an email using the dotnet framework. Here is the template that I'm using to create the message:  Date of Hire: %HireDate% Annual Salary: %AnnualIncome% Reason for Request: %ReasonForRequest%  Name of Voluntary Employee: %FirstName% %LastName% Total Coverage Applied For:  %EECoverageAmount% Guaranteed Coverage Portion: %GICoveragePortion% Amount Subject to Medical Evident: %GIOverage%   When the messages is received in outlook, outlook tells me "Extra line breaks in this message were removed". And the message displays like this:  Date of Hire: 9/28/2001 Annual Salary: $100,000 Reason for Request: New Hire  Name of Voluntary Employee: Ronald Weasley Total Coverage Applied For:  $500,000 Guaranteed Coverage Portion: $300,000.00 Amount Subject to Medical Evident: $200,000   Note how Outlook incorrectly removes needed line breaks after the name, EECoverageAmount, etc...  It's important for the email recepients to get a correctly formatted email, and I have to assume that some of them use outlook 2003. I also can't assume they will know enough to shutoff the autoclean feature to get the message to format properly.   I have viewed these messages in other mail clients and they display correctly  some more information:   I am using UTF-8 BodyEncoding (msg.BodyEncoding = System.Text.Encoding.UTF8) The msg.Body is being read from a UTF-8 encoded text file, and each line is terminated with a crlf.   Question: How do I change the format of the message to avoid this problem?


What is the difference between    "They are bad." and  "Those are bad."?   What are the conditions in which you'd choose one in favor of the other.  First off, I'm not sure that they aren't interchangeable.  Even if they are, I can't tell if the difference is between "they" referring to people, and "those" referring to things, of if there is something about the "demonstrativeness" of the they vs. those that makes a difference, or something else.  The problem that I'm dealing with doesn't have a context that defines what people/objects the pronoun is referring to.  I'm learning Swedish on Duolingo; I translated a sentence (De är dåliga.)  with "Those are bad", the site claims that this is wrong, and "They are bad" is the correct translation.  But mentally reviewing it, I'm not sure what/if there is a difference between these, in English.  If these two are pretty much interchangeable, then I'd post a request that "my answer is correct" to the website.    Although prompted by situation involving a foreign language, my question is just about how to make sense of the difference in English, and so on-topic here.

In the following example conversation, what will be the best way to ask if the given resources help the person?  Example conversation:     John: Hey Joe, I need to improve my chess, please help.   Joe: Hello John, please check these links:  and .   Let me know if [those, they, that] help(s).   Thanks!


In my C dive i have 15.3 GB free available space. Get Windows Icon shows that my laptop is fully compatible for windows 10 update.   but it has been the third time it failed to update my pc from windows 8.1 to windows 10 :( and i am highly disappointed :(   Here is the error message:  What that error code means and what would be a fix for this problem?

I am running a 64-bit version of Windows 7 Home Basic. I am trying to update the Windows but the update fails with an error code 80072EE2. I am connected to the internet through proxy.  Here are some things listed in my WindowsUpdate.log:  Access type: No proxy WSUS server: <NULL> WSUS status server: <NULL>   Then the download manager is restoring some persisted download calls. Then,  Initializing Automatic Updates WARNING: SendRequest failed with hr = 80072ee7. Proxy List used: <(null)> Bypass List used : <(null)> Auth Schemes used : <> UpdateDownloadProperties: download priority has changed from 1 to 2. WARNING: Failed to change download properties of call, error = 0x80070057 WARNING: WinHttp: SendRequestToServerForFileInformation MakeRequest failed. error 0x8024402c WARNING: WinHttp: SendRequestToServerForFileInformation failed with 0x8024402c WARNING: WinHttp: ShouldFileBeDownloaded failed with 0x8024402c Error 0x8024402c occurred while downloading update; notifying dependent calls.   There are very many errors/warnings and some other things listed in the log file. I have copied above the ones I thought are relevant to my problem.  Note that I have tried the solution provided on the Microsoft website but that was unable to solve my problem.  Can someone help me resolve this error?


I made my abstract page and used two languages in it.  I would like to typeset the page number in roman but it doesn't work.  \documentclass[12pt,a4paper]{report} \usepackage[utf8]{inputenc} \usepackage[english,arabic]{babel} \usepackage[LAE,LFE]{fontenc} \usepackage{graphicx} \usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry} \begin{document} \pagenumbering{roman} \setcounter{page}{3} \selectlanguage{english} \chapter*{ABSTRACT}  \selectlanguage{arabic} \begin{flushleft} \textbf{{\Large : ملخص}} \end{flushleft}الهدف من هذا المشروع هو تصميم وتنفيذ نظام لإدارة المجلس التأديبي على شبكة الإنترنت، لقسم الإعلام الآلي في جامعة عباس لغرور، برمجة هذا النظام تمت من خلال دراسة تفصيلية عن طريق استعمال يو أم أل  والتنفيذ تم باستعمال لغة البرمجة  بي إتش بي ونظام إدارة قاعدة البيانات  ماي إس كيو إل، للمساعدة في إدارة المهام المتعلقة بمجلس التأديب مثل : حفظ التاريخ التأديبي للطالب، إدارة الوثائق التربوية (تقرير سوء السلوك، القرار النهائي ...) ضمان التواصل بين أعضاء مجلس الإدارة ورئيس القسم (استخدام الاستدعاء)، والتخفيف من العلاجات في المجلس الذي كان يستغرق وقتا طويلا لأسباب مثل: المعالجة اليدوية للمعلومات، وجود عدد كبير من السجلات وعدم وجود شكل موحد للتقارير والاستدعاء. \selectlanguage{english} \begin{flushleft} \textbf{{\Large Abstract:}} \end{flushleft}\selectlanguage{english} The aim of this project  is to design and implement a web based disciplinary board management system, for the department of informatics in the university of Abbas Laghrour ,for modelling the system we used UML language and for the implementation we used  PHP language and MyQSL data base ,to help with the management of task related to disciplinary board such as : saving the disciplinary history of the student ,managing the pedagogical documents(report of misconduct, final decision …) ensuring communication between board members and department chief (using convocation) ,and to alleviate the treatments of the  board which used to take too much time  for reasons such as : the manual processing of information ,the big number of registers and the lack of a standard format for reports and convocation. \begin{flushleft} \textbf{{\Large Résumé:}} \end{flushleft} Le but de ce projet est de concevoir et mettre en place un système de gestion de conseil disciplinaire basé sur le Web, pour le département de l'informatique de l'université d'Abbas Laghrour,Pour la modélisation du système on a utilisé le langage UML et pur l'implimentation on a utilisé le langage PHP et la base de données MyQSL, pour aider à la gestion des tâches liées au conseil de discipline en tant que: sauvegarder les antécédents disciplinaires de les etudiants, gérer les documents pédagogiques (rapport d'inconduite, décision finale ...) assurer la communication entre les membres du conseil d'administration et le chef du département (en utilisant la convocation) et pour atténuer les traitements du conseil qui prenait trop Temps pour des raisons telles que: le traitement manuel de l'information, le grand nombre de registres et le manque de format standard pour les rapports et la convocation. \newpage  \end{document}

My thesis format requires that pages appear before the first chapter to be numbered with Roman numerals and the main content of the thesis to be numbered with Arabic numbers. It seems that the arabic support in babel allows the Table of Contents to switch the page numbering style for the later appear pages to Arabic. My thesis content relies heavily on arabic content so I can not switch the babel support.  This is the shortest example that produces the problem. Notice that the number of the TOC page is "5" instead of "V". If we remove arabic from babel the problem will be fixed.  \documentclass[12pt]{book} \usepackage[arabic,main=english]{babel}   \begin{document}  \pagenumbering{gobble} \title{\bf{Title of Dissertation}}  \vspace*{3\baselineskip} \centerline{\bf{Polyglot: A Massive Multilingual Natural Language Processing Pipeline}} \vspace*{1\baselineskip} \centerline{A Dissertation presented}  \newpage  \pagenumbering{roman} \setcounter{page}{2}  \centerline{\bf{Stony Brook University}} \vspace*{1\baselineskip}  \newpage  \centerline{Abstract of the Dissertation} \vspace*{1\baselineskip} \centerline{\bf{Polyglot: A Massive Multilingual Natural Language Processing Pipeline}}  \newpage \vspace*{4\baselineskip} \centerline{\textit{Dedicated to the refugee children across the world.}}   \tableofcontents  \listoffigures   \listoftables     \newpage \renewcommand{\thepage}{\roman{page}} \centerline{\bf{List of Abbreviations}} \vspace*{4\baselineskip} \begin{tabular}{ll} NLP & Natural Language Processing \\ NER & Named Entity Recognition\\ POS & Part of Speech\\ OOV & Out of Vocabulary \\ RNN & Recurrent Neural Network\\ LOC & Location \\ ORG & Organization \\ PER & Person \end{tabular}   \newpage \centerline{\bf{Acknowledgements}} \vspace*{4\baselineskip} I am grateful to have my PhD advisor  \newpage \centerline{\bf{Publications}} \vspace*{2\baselineskip}  \mainmatter   \chapter{Introduction}  \end{document}   Here is the wrong output    Here is what it should look like


I have gone through the entire about page for meta.stackexchange.com site thoroughly but I can still find no Informed badge awarded in my profile; why is that so? Is it some kind of technical error on the website?

There is an "Informed" badge for reading the meta about page but it was awarded zero times and to make sure I tried reading the about page but did not receive it. If the badge is to be awarded here, then this should be 'fixed'. If not, it should be removed from the list of badges.


Let $p ∈ \mathbb N, p ≥ 2$, show that :   $$(p − 1)!= −1 [p] \iff p \text{ is prime.}$$    Hint : For one direction, use the fact that $\mathbb F$ is a field and pair each element with its inverse.   I'm not sure where to start with this problem. Any help appreciated. Thanks!

How can I show that $(n-1)!\equiv-1 \pmod{n}$ if and only if $n$ is prime? Thanks.


If I know why the Euler Lagrange Equation is Equivalent with Newtons second law in Cartesian coordinate system why the Lagrange form is  yet valid with the same form  for other coordinate systems while newton law have a different form in each coordinate system? (As described at )  Anyone have a proof for it?

Suppose I have an inertial frame with coordinate $\{q\}$. Now I define another reference frame with coordinate $\{q'(q,\dot q,t)\}$. I obtain the equation of motion in $\{q'\}$ in two different ways:   First obtain the equation of motion in $\{q\}$ by the Euler Lagrange equation $$\frac{d}{dt}\left(\frac{\partial L}{\partial \dot q}\right)-\frac{\partial L}{\partial q}=0$$ and then rewrite the equation in terms of $\{q'\}$. First transform $L(q,t)$ to $L'(q',t)=L(q(q',t),t)$ and then obtain the equation of motion $$\frac{d}{dt}\left(\frac{\partial L'}{\partial \dot q'}\right)-\frac{\partial L'}{\partial q'}=0.$$   Are the two answers just the same?


Should and Could.  Both are used to indicate the possibility of a situation then what is the difference?

I am not referring to could as a past tense of can  What is the difference between the following sentences?     You should do it.   You could do it.


We are dual UK/Canadian citizens with both UK and Canadian passports. We reside in the UK. We will be travelling to the USA and Canada on holiday. Can we: -  leave UK on our UK passport and enter USA on Canadian pasport, then -  fly out of USA to Canada using our Canada passport -  fly back from Canada to UK with "in transit" stop in USA airport, using Canada passport to leave Canada and to get us through the "in transit" bit, and then re-enter UK on UK passport?  Alternative would be to get ESTA forms and to use our UK passports while travelling in USA and "in transit" in the USA

I was just wondering if you have two passports (a Chinese one and an Australian one), and you booked your airline ticket with the Chinese one, will you have to show both of your passports or just one?  The thing is, on my Chinese passport, it has my birth name, but then when I became an Australian citizen, I legally removed my Chinese name and replaced it with my English name. So I don't know whether I should just show the passport officials the one that I booked the airline ticket with.


I have basically no programming experience, and I essentially want someone to write a data script for me to use the SE data-mining ... thingy.  Is there a site where I can ask kind-hearted (or easy-reputation seeking) individuals to write a script for me?

The tag wiki for  says:  The Data Explorer, located at data.stackexchange.com, allows you to create and run queries against copies of the databases of popular StackExchange sites to investigate trends or satisfy your curiosity. For questions about the ,   So there's a link to the FAQ, but it seems to imply that data.stackexchange.com is the place to ask questions about Data Explorer (I can't find any questions about DE there, though). By contrast,  says questions are asked here. Which one is it?


I've heard some talk about ending sentences with prepositions. It seems like the overall consensus is that it is indeed okay.  But, I have come up with a few examples. I am wondering if it is "necessary" or just a choice of style here.   'Whom will you go to the party with'?  or   'With whom will you go to the party?'  Now, because of the sentence construction, you can put with before the whom. But do you need to do this? Is it acceptable to say "Whom will you go to the party with?'  Another example is when you use "which" with prepositions, where you have an option to put the preposition before which. (For which event are you preparing? vs. Which event are you preparing for?)  Is this just a matter of style or choice? Also, is there a more recommended option in formal writing?  As a separate question, is it also a "myth" that you can't use a split infinitive, especially in formal writing?

Like many others, I commonly find myself ending a sentence with a preposition.  Yes, it makes me cringe.  I usually rewrite the sentence, but sometimes (in emails) I just live with it.  To, with... you know who you are.  Should I keep fighting myself on this one, or is it okay in some circumstances?


How can I follow tags on Stack Overflow (so that the next time I log in, I can directly find my favorite questions from the main page)?

I know I can do this, but I just can't find the button...  How do I follow a tag?


While I can find lots of information about PoE, I'm finding little about "gotchas" or "warnings".  That being said, what would happen if I configured a switch to give PoE then plugged that into a device that doesn't support PoE?  Would it damage the endpoint device?

I have a switch with Power over Ethernet capabilities. Is it allowed to connect a PC to a PoE switch?


I'm new to C++. I want to use the header file Random.h (described here ). It uses unistd.h Which gives me an error    "Cannot open include file: 'unistd.h': No such file or directory"  I've googled around and seen that the issue is that unistd.h works with unix not visual express. Some posts suggest using mingw instead but I've tried that and it doesn't work. Can anyone tell me how to get unistd.h (or at least the bits of it I need) to work on Visual Express.  There are some suggestions online but I cant find anything that addresses my particular question. thanks!

I'm porting a relatively simple console program written for Unix to the Windows platform (). All the source files include "unistd.h", which doesn't exist.  Removing it, I get complaints about misssing prototypes for 'srandom', 'random', and 'getopt'. I know I can replace the random functions, and I'm pretty sure I can find/hack-up a getopt implementation.    But I'm sure others have run into the same challenge.  My question is: is there a port of "unistd.h" to Windows? At least one containg those functions which do have a native Windows implementation - I don't need pipes or forking.  EDIT:  I know I can create my very own "unistd.h" which contains replacements for the things I need - especially in this case, since it is a limited set. But since it seems like a common problem, I was wondering if someone had done the work already for a bigger subset of the functionality.  Switching to a different compiler or environment isn't possible at work - I'm stuck with Visual Studio.


Lately I'm working with a lot of Wordpress themes. When I have to edit a particular element, I usually use Firebug to see the element's name so I can change the CSS. I think I understand the difference between IDs and Classes, Classes are used for a group of elements that you want to share the same styling, and ID is usually used for a single element.  Here's the thing, I'm seeing so many elements in these Wordpress themes that are only used once, but they are assigned to a class. A good example is the website logo. Isn't the logo only used once? Shouldn't it be assigned to an ID? Why is it always assigned to a class?

What's the difference between
 and
 when it comes to CSS? Is it alright to use
?  I see different developers doing this in both ways, and since I'm self taught, I've never really figured it out.


I'm working on the following problem:     Determine the fixed field of the automorphism $t\mapsto t+1$ of $k(t)$. (Ex 7, section 14.1, Abstract Algebra by Dummit & Foote).    Here is my attempt of a solution:  Let be $\sigma$ the automorphism determined by $t\mapsto t+1$ and fixing $k$. An arbitrary element of $\alpha(t)\in k(t)$ has the form $\alpha(t)=\dfrac{p(t)}{q(t)}$ with $p,q\in k\left[ t\right]$. We can take $p,q$ such that $(p,q)=1$ and $q$ monic. If $\alpha$ is a fixed element by $\sigma$, then we have $\alpha(t)=\alpha(t+1)$, so that $\dfrac{p(t)}{q(t)}=\dfrac{p(t+1)}{q(t+1)}$ and finally $p(t)q(t+1)=p(t+1)q(t)$. As $(p,q)=1$, $q(t)$ must divide $q(t+1)$. By the same reason, $q(t)$ must divide $q(t+1)$, and as we took $q$ monic, we conclude that $q(t+1)=q(t)$, ie, $\sigma(q(t))=q(t)$. Now we note that, as $\sigma$ fixes both $\alpha(t)$ and $q(t)$, it must also fix $p(t)$.  Now I'm getting stuck. If the characteristic of the field $k$ is $0$, I can say both $p$ and $q$ have an infinite number of roots (if they're not constant polynomials), so both have to be constant. But if the characteristic is non-zero, I can't conclude in the same way. What can I say about the polynomials?  Thanks in advance!

Suppose $k$ is a field, and $k(t)$ is the rational function field. If $f(t)=P(t)/Q(t)$ for some polynomials $P(t)$ and $Q(t)\neq 0$, then the map $t\mapsto t+1$ sends $f(t)$ to $f(t+1)$.   So the fixed field for this map the set of rational functions $P(t)/Q(t)$ such that $$ \frac{P(t)}{Q(t)}=\frac{P(t+1)}{Q(t+1)}\text{ or }P(t)Q(t+1)=P(t+1)Q(t). $$ This does not seem awfully descriptive. Is there a more explicit description of what the fixed field looks like, (perhaps in terms of the form of $P$ and $Q$?), in order to get a better handle on it?   Later: With the wonderful help of Professor Suárez-Alvarez, I understand that the $\sigma$-invariant polynomials in $k[t]$ have all factors of form $\phi_\alpha$ where $\phi_\alpha=\prod_{i=1}^{p-1} (t-\alpha-i)$ for $\alpha$ a root of $f$ in $k$ when $k$ is algebraically closed.  What happens when $k$ is not algebraically closed? I think you can still factor out polynomials of form $\phi_\alpha$ for $\alpha$ roots of $f$ in $k$. But if $f$ does not split completely then there will be some $\sigma$-invariant factor with not roots in $k$ in the factorization of $f$. Is there anything more one can say to describe this remaining part? Or is that about the best we can do? Thank you for your time.


Is it possible to revise XYZ Math parametric equations without deleting the object and starting over?

When you first add a cylinder, you have the option to change the number of vertices, etc, but once you do anything else in blender, it seems you no longer can edit those parameters.   Is there a setting anywhere or an add-on that allows these parameters to be edited later on? If not, how easy would such an addon/feature be to create for anyone reading this?


I'm a software developer. I'm working up to 10 hours per day in computer.    How to properly adjust monitor brightness and contrast.

This days, it seems that I either go worse with my eyes or some settings with contrast and brightness have been changed.  However, I have been searching now for some tutorial on how to adjust contrast and brightness, and I have found already some, on how to use Microsoft Win7 Calibrate Display Color program, but some people don't recommend it.  My monitor control menu shows settings (which are by default) that contrast is set to 80, brightness to 90 and sharpnes to 45, for which I believe are quite high.  I'm usually every day in front of my PC about 6-10 hours.  The biggest problem is, when the night comes, and I have to read some Microsoft Word document, after a 10-15 minutes of reading, eyes starts hurting.  I'm using ASUS VW198 and Nvidia 9800 GT graphic card.  So please suggest to me which should I decrease: contrast or brightness or both?


I have an issue with referencing inside the text, i use the \label for every figure I have and Table, but when i state in my text that see Figure \ref instead of giving me Figure 5 (or etc) it gives me Figure 4.1 which represent the section that the table of figure is written in.  \documentclass[authoryear,preprint,review,12pt]{elsarticle} \usepackage{graphicx} \usepackage{float} \usepackage{amssymb} \usepackage{amsthm} \usepackage{mathtools} \usepackage{adjustbox}   \usepackage{lineno}  \begin{document}  \begin{flushleft} \begin{figure}[H]\label{East} \includegraphics[width=1.3\textwidth,keepaspectratio]{figures/2.pdf} \caption{mesh } \end{figure} \end{flushleft}  The part of the text that tell that you have to see Figure \ref{East}       \end{document}   Is there a way to cross reference my text and have the actual numbers of Figures of tables that i cross reference

\documentclass{article} \usepackage{algorithm}  \begin{document} \setcounter{section}{54} \section{A section with no label} \begin{algorithm} \label{myalg} \caption{An algorithm with the label `myalg'.} \end{algorithm} Reference to myalg: \ref{myalg}. \end{document}   With this code, the reference givens 55 (the section number); if I move the label after the caption command, I get the correct reference (1).  Why should this be the case? I find it confusing: when thinking about an algorithm as an environment, you expect to be able to label it right after you began it. At the very least I would expect some kind of error or "??" to appear, rather than the previous environment or reference-able entity being used.


I don't have much info on this one, other than it happened some time ago (can't pinpoint what could've caused it) and a reboot doesn't fix it.  Here are a couple of screenshots:      I'm completely clueless and so are the friends I asked. What could be the problem?

I have a problem in showing memory in task manager with memory and paging columns. Why it shows so small size usage? And maybe anyone knows how to fix it?  Here is a screenshot(working set, memory, page pool) sorted by most consuming:


I have a pen-tablet, and under XP it simply connected and worked in apps.  now in windows 7, it starts up 4+ extra programs to adapt to being used as a tablet PC- except that the computer is not a tablet PC,it's a desktop with a basic tablet plugged into it. is it possible to make windows stop loading up all these extra features when they are not needed?

I'm the owner of an HP Pavillion tx2120us tablet PC, which has a known problem of making the cursor jump to the lower right corner of the screen.  I've narrowed the problem down to the pen tablet function, since in Vista I was able to turn the tablet input process down, and the problem seemed to go away. It was a simple matter of just opening the task admin and killing the process.   However, as far as I can tell, I can't find the same process in Windows 7, and I have supposedly already turned the tablet functions via "Start" -> "Control Panel" > "Programs and Features" > "Turn Windows features on or off". Yet after a reboot the screen still seems to react to the tablet pen.  How can I finally turn the darned tablet functions off (while still being able to re-enable them in the future)?  EDIT: I have also turned the service off and restarting, , to no avail.


I wonder how to explain this regular zero article in such constructions:  Ray Bradbury, author of Fahrentheit 451. Karl Marx, creator of Marxism.  I can see that the second example may be explained as a title or something like this. But what is the first one?

What's the difference in the usage of the article "the" with the word "author"? Why is the article "the" left in the second sentence?     She's the author of "The Power of Glamour," "The Future and Its   Enemies" and "The Substance of Style."       She's author of the new book,   “The Intimidation Game: How the Left is Silencing Free Speech.”


Pretend I know how to do something that a lot of people can't do or don't know how to, can I do a question like "How can I start a jar file with a batch file?" and answer it? Is that allowed?  P.S.  is different from mine (At least I think it was unclear.)

I might want to answer my own question because:  I arrived at a solution before there were any other correct answers or I like mine better, can I still answer my own question?  I have a folder with lists of code snippets for things I always forget or get wrong, such as regular expressions for processing XML, common WinForms control idioms, etc. Is it considered poor etiquette for Stack Overflow to ask a question I already know the answer to, and then self answer, just so it gets recorded on the website?   Related:          For more information, see "" in the .