Command stat -c%w /home/knezi/file returns just dash. It means, according to the documentation, that the date of birth in unknown. I've tried plenty of files but all with the same result.  The question is: do I need to turn on timestamping of filesystem (note that last access and modification work)? Or what else could possibly be the problem?  I'm running Arch Linux - 64b, FS ext4 (tried also on tmpfs).

I was just reading up on the Birth section of stat and it appears ext4 should support it, but even a file I just created leaves it empty.    ~  % touch test                                                       slave-iv  ~  % stat test.pl                                                     slave-iv   File: ‘test.pl’   Size: 173             Blocks: 8          IO Block: 4096   regular file Device: 903h/2307d      Inode: 41943086    Links: 1 Access: (0600/-rw-------)  Uid: ( 1000/xenoterracide)   Gid: (  100/   users) Access: 2012-09-22 18:22:16.924634497 -0500 Modify: 2012-09-22 18:22:16.924634497 -0500 Change: 2012-09-22 18:22:16.947967935 -0500  Birth: -   ~  % sudo tune2fs -l /dev/md3 | psp4                                  slave-iv tune2fs 1.42.5 (29-Jul-2012) Filesystem volume name:   home Last mounted on:          /home Filesystem UUID:          ab2e39fb-acdd-416a-9e10-b501498056de Filesystem magic number:  0xEF53 Filesystem revision #:    1 (dynamic) Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize Filesystem flags:         signed_directory_hash  Default mount options:    journal_data Filesystem state:         clean Errors behavior:          Continue Filesystem OS type:       Linux Inode count:              59736064 Block count:              238920960 Reserved block count:     11946048 Free blocks:              34486248 Free inodes:              59610013 First block:              0 Block size:               4096 Fragment size:            4096 Reserved GDT blocks:      967 Blocks per group:         32768 Fragments per group:      32768 Inodes per group:         8192 Inode blocks per group:   512 RAID stride:              128 RAID stripe width:        256 Flex block group size:    16 Filesystem created:       Mon May 31 20:36:30 2010 Last mount time:          Sat Oct  6 11:01:01 2012 Last write time:          Sat Oct  6 11:01:01 2012 Mount count:              14 Maximum mount count:      34 Last checked:             Tue Jul 10 08:26:37 2012 Check interval:           15552000 (6 months) Next check after:         Sun Jan  6 07:26:37 2013 Lifetime writes:          7255 GB Reserved blocks uid:      0 (user root) Reserved blocks gid:      0 (group root) First inode:              11 Inode size:           256 Required extra isize:     28 Desired extra isize:      28 Journal inode:            8 First orphan inode:       55313243 Default directory hash:   half_md4 Directory Hash Seed:      442c66e8-8b67-4a8c-92a6-2e2d0c220044 Journal backup:           inode blocks   Why doesn't my ext4 partition populate this field?


Is the following grammatical?     Should I send the letter to her?   If it is, then how come that send can also be used without to?     Should I send her the letter?   What about the use of send in a sentence like "It sent her mad"?

Are both of the following sentences correct?  Let me know if there is still something I need to send to you. Let me know if there is still something I need to send you.  Which one is more appropriate to use?


So I know you can do "stringOne" + "stringTwo" to add two strings together. However I saw that you can use the stringOne.concat(stringTwo); What is the difference?

Assuming String a and b:  a += b a = a.concat(b)   Under the hood, are they the same thing?  Here is concat decompiled as reference. I'd like to be able to decompile the + operator as well to see what that does.  public String concat(String s) {      int i = s.length();     if (i == 0) {         return this;     }     else {         char ac[] = new char[count + i];         getChars(0, count, ac, 0);         s.getChars(0, i, ac, count);         return new String(0, count + i, ac);     } }


I'm curious as to what my old school reputation score would be on some Stack Exchange sites. Is there anywhere that I can see what my old school reputation score would be? For a period of time it looked like Area 51 had not updated and you could see everyone's reputations based off of the old rules, but that looks like it has  been fixed now.   Any ideas?

and will be retroactively applied.  I know that the  when this takes place. I know that it will .  But, if I do not document how much rep I had on a particular site prior to the change taking place and compare it to my recalculated rep, is there a way to know how much rep I gained due to the new system?


I'm in a discussion with Cybersecurity Team on the company that I work. I'm trying dealing to allow again this integration in our environment. The Cyber guys expose this  detail. I search on the web if this had been fixed, looked too in , but not found news about it. Someone know if this vulnerability it was fixed? PS: I'm using Ubuntu 20.04.2 LTS.

Today a couple of buffer overflows in NTP were announced , . It looks like updating my system to fix these issues is in order.   How can I find out if they have been fixed in the Ubuntu repositories, such that if I were to run:   sudo apt-get update sudo apt-get upgrade   then the fix would get installed and the vulnerability closed?   Edit: The selected answer specifically addresses the question of how to identify if a given CVE has been fixed or not, "Does Ubuntu generally post timely security updates?"  is certainly related but not identical


Whenever I see tetration discussed here, I inevitably see it asserted that there's no consistent continuous definition for tetration. However, it seems to me that    If we restrict ourselves to positive real values, $^{\frac12}x=e^{W(\ln x)}$ is the only consistent definition for $^{\frac12}x$; and This definition is sufficient to define tetration to any real height, if we further say that $\displaystyle^tx = {\lim_{a \to t}}\; ^ax$. So, what gives? I don't especially think I'm smarter than professional mathematicians, so if there's an inconsistency I'd like to be able to recognize it. Is there?

Recently I've come across 'tetration' in my studies of math, and I've become intrigued how they can be evaluated when the "tetration number" is not whole. For those who do not know, tetrations are the next in sequence of iteration functions. (The first three being addition, multiplication, and exponentiation, while the proceeding iteration function is pentation)   As an example, 2 with a tetration number of 2 is equal to $$2^2$$ 3 with a tetration number of 3 is equal to $$3^{3^3}$$ and so forth.  My question is simply, or maybe not so simply, what is the value of a number "raised" to a fractional tetration number. What would the value of 3 with a tetration number of 4/3 be?  Thanks for anyone's insight


I have recently installed the Ubuntu environment Cinnamon and really like its look and feel but it is not without its issues and I have had to find patches or fixes.  This includes reinstalling.  sudo apt-get install cinnamon-desktop-environment  However, the only version I seem to find is the full suite distro (with Libro, a million little games and such) Wondering if there is a stripped down core of all necessaries without the bloat. Thanks! p.s.  If anyone has any reinstall fix it tips specific to Cinnamon - I'd be more than happy to hear about them.

I have a fresh Ubuntu install and want to install Cinnamon as the desktop environment. When I do apt search cinnamon, I get multiple results, but two seems like they are the correct one.   The first is just   cinnamon/xenial 2.8.6-1ubuntu1 amd64 all     Innovative and comfortable desktop (Common data files)   while the other is   cinnamon-desktop-environment/xenial,xenial 2.8.0 all     Cinnamon desktop environment - full desktop with extra components   What's the difference between the two? What does the cinnamon-desktop-environment package contain that the cinnamon doesn't?


I'm setting up a headless system and somewhere along the line the humanity-icon-theme package gets installed. Normally this wouldn't matter much, but the filenames in this package are very long and are causing problems: the filesystem I'm targeting doesn't support such long names, and when they get truncated, two files with the same prefix end up conflicting. If I remove this package, apt wants to uninstall bunch of useful dependent packages that have GUI features I'll never use. Can I force apt to remove the package but keep the others? I figure it will complain about holding broken packages if I try.

Being an early adopter and using 11.04 daily builds I sometimes meet a situation when some packages require earlier versions of other packages than those I have installed. Usually newer (but refused) versions of needed packages provide all the functionality of their older versions.  If I use dpkg -i --force-depends-version to install dependent packages everything works fine, I've never seen a problem.  Instead of manually downloading and installing every package, can I just make the system pretend there is a specific package version installed when there is a newer? Or is there a --force-depends-version key equivalent for apt-get?


New Linux distros come with some quite sensible system vim settings that are mostly ok to use, but I would still like to override some of them. For example the default Ubuntu and Raspbian vim config has mouse support on (set mouse=a) which I don't like. However as soon as I create ~/.vimrc and put set mouse= in there, or any other setting for that matter, I lose all the system settings, like syntax highlighting, indentation, etc and vim comes up with very basic defaults. How can I keep the systems settings while overriding just one or two of them?  Simple test case:  Start Debian in docker with docker run --rm -it debian:latest  Once started install VIM with: apt update && apt -y install vim  Test vim /etc/passwd:   touch ~/.vimrc - just creating the file is enough  Test vim /etc/passwd again:    In the first case the system settings like syntax highlighting and mouse support is configured, but as soon as I create (even empty) ~/.vimrc then vim comes up with just the basic default settings. It's a default Debian vim: root@213ccd4660db:/# vim --version VIM - Vi IMproved 8.1 (2018 May 18, compiled Jun 15 2019 16:41:15) Included patches: 1-875, 878, 884, 948, 1046, 1365-1368, 1382, 1401

I'm currently logged into a server via ssh with ssh -Y and running a tmux session. If I start vim and run :colorscheme elflord the color scheme is changed. (Although the colors are not exactly what I would expect although they are I think 256 color. If I create a ~/.vimrc file and put a single line colorscheme elflord  in it then when I run vim it shows no color (just white text) and I cannot change the color with the :colorscheme command.


How can I make a string variable containing path to my win-app executable folder? I know that there's the simple command Application.ExecutablePath which returns all the path including the .exe name, but I need that path without the .exe name.

I would like to get the path to the execution directory of a Windows Forms application. (That is, the directory in which the executable is located.)  Does anyone know of a built-in method in .NET to do this?


For the given code what's the time complexity in Big-O notation ?  for(int i = 1; i <= n; i++)     for(int j = 1; j <= n; j = j + i)              some_constant_statement   If I'm not wrong  First loop take  n times Second loop n.long(n) time For Second loop :  n + n/2 + n/3 + n/4 +...................n/n times n(1 + 1/2 + 1/3 + ..............1/n) times means n(long(n)) time So, time complexity of entire piece of code is n.n.long(n)   Please correct me guys if I'm wrong .

I need to calculate the time complexity of the following code:  for (i = 1; i <= n; i++) {   for(j = 1; j <= i; j++)   {    // Some code   } }   Is it O(n^2)?


List of comics in which Batman became a murderer or a psychopath? That is someone else had to stop Batman.

Superman has been exploited by Poison Ivy in Hush, and he's definitely mad in Injustice. What about Batman? Has Batman ever had to be brought to justice/stopped/killed by his fellow superheroes? (That one time when Superman dreams of Batman snapping Joker's neck doesn't count)  Edit: The Dark Knight Returns doesn't count: Batman wasn't really mad, and he wasn't wrong either.


I am an allium lover with a strong allergy to all alliums. It is technically a sensitivity, as it isn't an instant reaction, but spending an hour in the bathroom because of one stray piece of red onion warrants a scarier word then "sensitivity". For those not familiar with plant taxonomy, alliums are the plant family that holds garlic, onions, chives, and leeks.  My allergy is progressively getting stronger and I can no longer lie to myself. I need a good substitute for that fantastic allium taste. Right now I can still eat garlic in reasonable amounts (thank god), but red onions are out, and everything else from white onions to leeks is somewhere in between. Any and all preparations of allium trigger the allergy, so no onion powder.  I am desperately looking for a non-allium onion substitute. My hope and dream is something that tastes like onion but isn't an allium. I would accept any strongly flavoured class of plants to switch addictions to.

I am going to be cooking for someone who, because of Crohn's disease, is unable to eat pretty much anything from the allium family (ie. onions, garlic, shallots, chives, scallions and leeks; this includes garlic and onion powder), as well as spicy food (so that excludes chilis and piquant spices). I have seen  but because the suggestions there are pretty much other alliums, it is not very helpful for my purposes.  Because onions tends to be in a lot of things (if nothing else, as half of a mirepoix, which tends to appear in many recipes, and is also the base of stocks, which makes things complicated -- I am not 100% sure if the two degrees of separation from onion to stock to whatever the stock is used for is enough to make it "safe", and unfortunately I won't have time to make an onion-less stock), I am not really sure what I can use instead.  I realize that it might be hard to substitute onions and garlic with other similar tasting ingredients without using other alliums, so instead, I am looking for suggestions to replace onions and garlic with things that will still let me cook flavourful food (that doesn't necessarily need to taste the same as it would with alliums, though).   For example, I was thinking about roasting a chicken and making a couscous dressing, but the chicken would sit on mirepoix (can I replace the onions in it with something else?) which would be used as a base for the sauce as well; and my couscous dressing recipe uses shallots (as well as sage, thyme, oregano and pine nuts). General suggestions would be useful as well, though.  Any suggestions would be greatly appreciated!


Note- this is for Windows 7.. this one  is  for vista   So it is not a duplicate.. And also the changing the resolution(the accepted answer on that one), didn't fix it for me.  there may be a windows 7 specific answer    Here is a bit of the desktop.    At some point some old bit of GUI appeared and won't go away.  Here it is hovering as I write this question.    It just sits there. And as you can no doubt appreciate,  it is a nuisance.  I've tried clicking in the bottom left to mimimize all the windows and clicking again to restore but nope. And i've tried opening a window over it but it just won't paint over it. The unwanted bit of GUI stays on top of anything.  I have tried opening task manager, end tasking explorer and starting explorer again, but nope, still there. so besides restarting windows, what can I do?  added  And I tried the accepted answer here   (and probably some others too) and the accepted answer of changing resolution, and some others I tried there, didn't work

Occasionally, I get part of an application lingering behind on my desktop:    This is part of a context menu for an application. It is always top-most, meaning that it is always on the screen, and I cannot click on it (it just clicks through it). It has happened before, sometimes with whole windows. It remains on screen even if the application it originated from is no longer running.  How do I get rid of it without rebooting?


Crass as it may be I have to find a suitable alternative to "circle jerk" which describes a situation in which everyone agrees about some subject but still love getting worked up about it and feed off each other's passion.  I have heard of "echo chamber" but it doesn't work for me.

Someone asked in the Math.StackExchange chatroom what a "more refined word for circlejerk" might be. UrbanDictionary defines this (in our desired usage) as:   [...] pompous, self-congratulatory discussion where little to no progress is made.  A group discussion or activity between like-minded individuals that validates mutual biases or goals in a non-confrontational environment.  Sometimes used to describe an internet forum thread where forum members all give each other kudos (Or rep where a rep system is present) for some non-event that has occurred.    I guess it's related to "intellectual masturbation" or "echo chamber" but these don't quite fit the bill.


I have an SQL (Oracle Solution) output  which looks like below:    ID        Value 1         31  1         44 2         31 3         22   4         57   4         69     ID and value are brought in from different tables using an inner join.   When I select ID and Value, I am wanting to concatenate the value (separated by a comma) when the ID is a match, so that it looks like below:  ID        Value 1         31,44  2         31 3         22   4         57,69    How can I make this happen?

Consider a database table holding names, with three rows:  Peter Paul Mary   Is there an easy way to turn this into a single string of Peter, Paul, Mary?


I was reading a  published on Dropout. What I find difficulty in understanding that, In the training phase, a unit is present with a probability p and not present with a probability 1-p. In the test phase, all units are present, but we multiply each of them with the probability.   Now, is it like, let we have 4 input units originally named a,b,c,d. In the training stage, after applying dropout, with a dropout rate of 0.5, we are left with units a and c. So, As in the test stage, all the units are present, so, is it like, we multiply each of the units with 0.5? Also, Is p defined for each of the units in the network, or for the entire Neural Network?  Also, In doing so, how is the result same for training and test stage?

When applying dropout in artificial neural networks, one needs to compensate for the fact that at training time a portion of the neurons were deactivated. To do so, there exist two common strategies:   scaling the activation at test time inverting the dropout during the training phase   The two strategies are summarized in the  below, taken from .  Which strategy is preferable, and why?    Scaling the activation at test time:    Inverting the dropout during the training phase:


I am trying to send a record from my apex controller to my component but am receiving:     List has more than 1 row for assignment to SObject   Apex Code:          @auraenabled public static Event_Registration__c isRegistered(Id recordId){   Id userId = UserInfo.getUserId();     Id contactId = [SELECT ID FROM Contact WHERE OwnerId = :userId].Id;     List<Event_Registration__c> registrationList = [SELECT ID FROM Event_Registration__c WHERE Event__c = :recordId AND Contact__c = :contactId];     Event_Registration__c er = (registrationList.size() > 0 ) ? registrationList[0] : null;     return er; }   JS Controller:      isRegistered : function(component, event) {      var action = component.get("c.isRegistered");     action.setParams({ recordId : component.get("v.recordId") });     console.log('params set');     action.setCallback(this, function(response) {         var state = response.getState();         if (state === "SUCCESS") {             console.log(response.getReturnValue());             var eventReg = response.getReturnValue();              if(eventReg != null){                 component.set("v.registered", true);             }             else{                 component.set("v.registered", false);             }         }         else if (state === "INCOMPLETE") {             // do something         }             else if (state === "ERROR") {                 var errors = response.getError();                 if (errors) {                     if (errors[0] && errors[0].message) {                         console.log("Error message: " +                                      errors[0].message);                     }                 } else {                     console.log("Unknown error");                 }             }     });     $A.enqueueAction(action);         },

I am trying to write a VF page to list all the id and name columns from a custom object but found an error "List has more than 1 row" in the VF page.  Can anyone tell me what have I done wrong?  VF Page:  <apex:page Controller="MP_controller" showHeader="false" sidebar="false">   <apex:pageBlock>      <apex:pageBlockTable value="{! mp}" var="item">         <apex:column value="{! item.id}"/>         <apex:column value="{! item.name}"/>       </apex:pageBlockTable>   </apex:pageBlock> </apex:page>   Apex controller  global with sharing class MP_controller {     public Merchant_Profile__c mp{get;set;}     public MP_controller(){         mp = [SELECT                  ID, name, Profile_account_name__c, Merchant_ID__c, Bank_Code__c, Country_Code__c,                 Currency_Code__c, Merchant_Level__c, Merchant_Type__c, MSO__c, Region__c,                 Retail_Products__c, Transaction_Mode__c, Created_Date__c, Date_Disabled__c, Date_Live__c,                 Merchant_Category_Code__c                FROM Merchant_Profile__c               WHERE Profile_Account_Name__c = '001O000000bQFnyIAG'];     } }


I would like to determine all units of the domain $\mathbb{Z}[\sqrt{2}]$.    Recall that if $D$ is an integral domain, then a unit of $D$ is an associate of the multiplicative identity $1$, i.e. $u \in D$ is a unit iff $u$ divides $1$ and $1$ also divides $u$. Equivalently, $u \in D$ is a unit iff it is a divisor of $1$, i.e.  iff $\exists x \in D$ such that $ux=1$.  Thus, units are also called invertible elements.  The set $\mathbb{Z}[\sqrt{2}] := \{a+b \sqrt{2}: a,b \in \mathbb{Z} \}$, under the usual addition and multiplication operations, forms a domain.  How do I find all its units?  Suppose $a+b \sqrt{2}$ is a unit. Then $(a+b \sqrt{2})(x+y \sqrt{2})=1$ for some $x,y \in \mathbb{Z}$. Thus, $ax+2by=1$ and $ay+bx=0$.  Solving for $x,y$, we obtain that $x=\frac{a}{a^2 - 2b^2}$ and $y=\frac{-b}{a^2 - 2b^2}$ must be integers.  How do I obtain the set of values of $a,b$ for which $x$ and $y$ are integral?   Since $(\sqrt{2}-1)(\sqrt{2}+1)= 2-1^2=1$, the two factors $\pm 1 + 1 \sqrt{2}$ are units.  Can we systematically find all the units of $\mathbb{Z}[\sqrt{2}]$?   This answer given  to a related question shows only that if $a+b \sqrt{2}$ is a unit and  is > 1, and if $a,b>0$, then $a+b \sqrt{2}$ is of the form $(1+\sqrt{2})^n$.  The case where $a,b$ are of opposite signs, and the case where the unit is between 0 and 1 (such units exist, for eg, $3-2 \sqrt{2}$) are open.

How can I show that the units $u$ of $R=\mathbb Z[\sqrt{2}]$ with $u>1$ are $(1+ \sqrt{2})^{n}$ ?   I have proved that the right ones are units because their module is one, and it is said to me to do it by induction on $b$ and multiplication by $-1+\sqrt{2}$. I have already shown that the units of this ring has norm $1$ and all the numbers with norm $1$ are units, this may help.


I’m sitting back doing some self-reflection (procrastination) when I start thinking about stocks. My basic understanding of stocks is that the owner ship of company is split up between owners of any class of shares (relative “power” of share determined by the shareholders agreement).   I can understand that if ever another entity is able acquire more than [insert percentage] of shares then they now control the company. I can understand a person wanting to share in the profits of the company and buys a share that pays dividends.  My curious question is why anyone not wanting to guide a company would buy shares in a company if those shares don’t pay dividends?   The only answer my brain came up with, which I hope is wrong. Is that the only reason to buy a share without dividends is the “gamble”. I equate the level of gambling  to that of poker and not lotto numbers. Skill (example: ability to read and understand a company’s quarterly report) does influence outcome greatly but in the end it is still just a gamble (The McAmazon Apple Company comes out a minute after you made a purchase and says that they’ve fired every employee and will be replacing them with imaginary Umpa lumpas… … Gamble lost).   This gamble makes a lot of sense where over time skillful and knowledgeable people profit over the ones who only think themselves to be skillful and knowledgeable. This like poker makes a medium where people can make a living off the mistakes of others.   I understand that this (gamble) is a part of the stock market and I’m not saying it is good or bad (I really don’t care) I’m just curious if there is a reason other than the gamble to own a stock with no dividends (Note: not planning a hostile takeover or ever casting a vote)  I know this questions seems very vague and broad but I'm 80% sure I'm going to get a straight up "No. People only trade dividendless stocks with the hope of making a profitable trade nothing else." I ask because I am not 100% sure and I hope that someone will show me something new.

I read somewhere that companies are not required to pay dividends to shareholders (this is correct, yes?).   If so, then if company A never pays dividends to its shareholders, then what is the point of owning company A's stock? Surely the right to one vote for company A's Board can't be that valuable.   What is it that I'm missing?


I run out of cards as others were asking for it using the combo multiple times on me - does this mean I lost? or is drawing multiple action or combo cards allowed in drawing?

In the Exploding Kittens game, the rules say     You won't ever run out of cards in the Draw Pile, so there is never any need for a reshuffle.   In every game I've played all the cards end up on the discard pile fairly quickly and there is nothing left in the draw pile, so we have to reuse them.  Is this meant to happen? Are we doing something wrong?


Let $L$ and $R$ be $n \times n$ matrices. Consider the following minimization problem  \begin{equation} \mathbf{L} = \min_{L \geq \mathbf{0}}  \mu\|\mathbf{L}\|_* + \dfrac{1}{2\lambda}\|\mathbf{L-R}\|_F^2 \end{equation}     By $\mathbf{L}$ $\geq$ 0 , i mean that i wish the entries of $\mathbf{L}$ to be non negative. I know the solution can be obtained using the singular value thresholding of $\mathbf{R}$ when the non-negativity constraint on $\mathbf{L}$ is not present. But I can't figure out the change needed in order to satisfy the non-negativity constraint on $\mathbf{L}$. Will simply setting the negative entries of $\mathbf{L}$ to zero work? This link  is about $\mathbf{L}$ being positive definite; my question is about the entries of $\mathbf{L}$ being non-negative. Can someone please answer this?

Let $L$ and $R$ be $n \times n$ matrices. I am trying to solve the following minimization problem  $$ L^{k+1} := \arg \min_{L} \lambda \|L\|_{\ast} + \frac{1}{2\mu}\|L-R^{k}\|_{F}^{2} $$ $$ \mbox{s.t.}\ L \succeq 0 $$  where $\|\cdot\|_{\ast}$ and $\|\cdot\|_{F}$ denote the nuclear and Frobenius norms, respectively. Also, $k$ expresses the $k$th iteration when solving an optimization problem successively.  I don't know how to solve this problem. Would you tell me the way?


I just got a used Macbook Pro (retina) 2012 running El Capitan. I am keeping it charged and on all the time. Is there any harmful effect from doing so on the battery in the long term?

My friend told me that I need to disconnect the power cord when the battery is fully charged. Otherwise, I will shorten the life of the battery.  Other people say you should drain it once a month or point out that for long term storage, you should charge it to 50% and then periodically (3 to 6 months) bring it back to 50% and store it again.  I am going to use my laptop at home 90% of the time. So, I plan to have the power cord connected all the time.  I'd prefer to just plugging in my MacBook Pro and letting it be on charge long term and occasionally taking it away from the charger when I'm not at home or my desk.  Are these specific recommendations worth the inconvenience?


How can two permanent magnets do work on each other?  If you put two magnets with opposite poles facing each other they will attract each other. If you put them with the same poles facing each other they will repel each other.  What is the mechanism behind this? A static $B$-field can do no work, and still the magnets will attract/repel.

I learned that the force from a magnetic field does no work. However I was wondering how magnets can be used to pick up pieces of metal like small paperclips and stuff. I also was wondering how magnets can stick to pieces of metal like a refrigerator?


How can we prove $e^{x+y}=e^{x}e^{y}$ by the power series $$e^{x}=\sum_{k=0}^{\infty}\dfrac{x^{k}}{k!}\,\,\,?$$  Is there any simple method?

In order to show $e^{x+y}=e^{x}e^{y}$ by using Exponential Series, I got the following:   $$e^{x}e^{y}=\Big(\sum_{n=0}^{\infty}{x^n \over n!}\Big)\cdot \Big(\sum_{n=0}^{\infty}{y^n \over n!}\Big)=\sum_{n=0}^{\infty}\sum_{k=0}^n{x^ky^n \over {k!n!}}$$  But, where should I go next to get $e^{x+y}=\sum_{n=0}^{\infty}{(x+y)^n \over n!}$.  Thanks in advance.


I am trying to add a repository in Debian 6.0.8  sudo cat /etc/debian_version 6.0.8  sudo apt-get install software-properties-common E: Unable to locate package software-properties-common  sudo apt-get install python-software-properties 0 upgraded, 0 newly installed, 0 to remove and 99 not upgraded.  sudo add-apt-repository ppa:kakrueger/openstreetmap sudo: add-apt-repository: command not found   Is any other alternative to install software from that repository?

In Ubuntu one can add a repository via following command -   sudo add-apt-repository ppa:yannubuntu/boot-repair   As Ubuntu is based on Debian code base, I was expecting that the same would work in Debian too, but it doesn't.   What is the reason for this? Is there some other shell command I can use to achieve the same?   Note:  I know I can edit /etc/apt/sources.list, but I want to achieve this from the shell. I also want to know why the same command won't work when the code base is the same.


Let $f: \mathbb{C} \backslash\left\{a_{1}, \ldots, a_{n}\right\}$ be holomorphic, prove that there exist entire function $f_0,f_1,...f_n$ s.t $$f(z)=f_{0}(z)+f_{1}\left(\frac{1}{z-a_{1}}\right)+\ldots+f_{n}\left(\frac{1}{z-a_{n}}\right)$$ What I think that this thing can be only true if $a_{1}, \ldots, a_{n}$ are removable singularity of $f$ but how can I infer the kind of the singularity points from that question givens? The reason I think this true only if those are removable points is that it looks $f$ is defined in those points.

Let's say I have a complex function like $$f(z)=z+e^{\frac{1}{z-1}}+\sin\left(\frac{1}{z-2}\right)$$ which is holomorphic in $\mathbb{C}\setminus \left \{ 1,2 \right \}$ Then there exist entire functions $$f_{0}(z)=z$$ $$f_{1}(z)=e^{z}$$ $$f_{2}(z)=\sin(z)$$ Such that, the equality $$f(z)=f_{0}(z)+f_{1}\left(\frac{1}{z-1}\right)+f_{2}\left(\frac{1}{z-2}\right)$$ holds for all points except for $z=1$ and $z=2$ which are essential singularities. My question is, can this be extended in general? Precisely put, let's say I have a holomorphic function $f(z)$ except for a finite number of essential singularity points $a_{1},\ldots,a_{n}$ in the complex plane. Is it true in general, that there exist $n+1$ entire functions $f_{0}(z),\ldots,f_{n}(z)$ such that: $$f_{i}(z) \text{ is holomorphic in }\mathbb{C}\setminus \left \{ a_{i} \right \} \text{ for }i=1,\ldots,n $$ $$f(z)=f_{0}(z)+f_{1}\left(\frac{1}{z-a_{1}}\right)+\ldots+f_{n}\left(\frac{1}{z-a_{n}}\right)$$


Direct product, semidirect product and central extension are different types of group extensions. Is there any other type? If there is, can you please give an example with a small finite group?

Consider the exact sequence  $1\to C_n\to G\to C_m\to 1$,  where $C_n$ and $C_m$ are finite cyclic groups. Then, what $G$ can be? Is it true that it is either dihedral, or a (semi)direct product of my cyclic groups?


My question is how to solve: Determine all entire functions $f$ with the property that if $|z|=1$, then $|f(z)|=1$.  I was thinking that I could solve this by first show that $f$ has to be a polynomial. Then I can use the formula  \begin{align*} f(z)=z^{n}(a_{n}+a_{n-1}/z+...+a_{1}/z^{n-1+a_{0}/z^{n}}) \end{align*} where $a_{n}\neq 0$. And then somehow show that  \begin{align*} f(z)=z^{n}a_{n}, \end{align*} with $|a_{n}|=1$. (I think that this is the answer.)   Could someone help me? What are the steps I should to?   Some theorems that my book covers and I think will be needed are Liouville's theorem, Maximum principle, fundamental theorem of algebra. Thanks!

Find all entire functions $f$ such that $|f|=1$ whenever $|z|=1$.  My conjecture : $f=cz^m,|c|=1,m \geq  0$.  But I don't know how to prove it.  I will appreciate your help.


I really enjoy working out rather unusual character builds, or taking a subpar character concept and try to make it work using min/maxing, point buy and having every level from one to twenty planned out before even starting the adventure (ability increases, feats, equipment, etc). My latest project is a wizard that is as tanky as possible (tanky meaning having high AC in this case).   To achieve this, my wizard would be a mountain dwarf (starting with light and medium armor proficiency), and have 14 Strength. Depending on how the campaign goes, around the time I'm getting close to having enough gold to buy a suit of plate armor I would forego an ability score increase in favour of the "Heavily Armored" feat (also giving me +1 Strength, raising that ability to the score needed to wear plate armor without getting a movement penalty.  Now, I would have an AC of 18, which is quite high for a wizard. But, as stated, my goal is for my character's AC to be as high as possible. Adding a shield to my character's equipment would seem like a cheap way to get an extra +2 AC for an impressive total of 20. But this is where I finally get close to my question.  Shields have a separate proficiency in 5E and wearing armor you are not proficient with not only imposes disadvantage on any ability check, saving throw, ar attack roll that involves Strength or Dexterity, but also makes it impossible to cast spells. Not being able to cast spells would make my wizard kind of pointless so in order to make this work I would somehow have to get proficiency with shields.  At this point there are two ways to get shield proficiency in 5E: multiclassing one level in a class that has shield proficiency or taking the "Moderately Armored" feat. Multiclassing isn't really an option for me since it would leave me unable to get the high level Wizard features. So I would have to take the feat just to get shield proficiency. Since I'm already proficient with medium armor this seems like a complete waste of a feat to me. If that is as it is intended to work I wouldn't take the feat.  So my question is: Is the Moderately Armored feat really the only way to get shield proficiency without multiclassing?  Because it sort of seems like an oversight. Now, the developers can't reasonably be expected to take in to account people like me creating stupidly specific situations like this: a heavily armored dwarf wizard who uses a shield (my character would still be able to perform the somatic components for spells even wielding a shield since he would not wield a weapon). For the vast majority of character builds this would never be an issue, but I really think shield proficiency should also be included in the "Heavily Armored" feat.  In my other wacky character concepts I have found that sticking to the rulebooks generally works out just fine. My DM also sticks to RAW and doesn't use any homebrew rules. Normally I'm all for sticking to RAW but this just seems kind of silly. According to the rulebook, my wizard could hold a chair in his left hand and would still be able to cast spells, but when he's holding a shield this is suddenly no longer possible.

In 5e, the Moderately Armored feat grants proficiency with both medium armor and shields. It is, that I can see, the only feat that grants proficiency with shields. Every single class that has proficiency with medium armor has proficiency with shields, and vice versa.  Mountain dwarves, on the other hand, give proficiency with medium armor, but make no mention of shields. As far as I can find, this is utterly unique within 5e.  So, are mountain dwarves proficient in shields? If not, am I correct in my understanding that every single way to gain that proficiency (class or feat) also grants medium armor proficiency, making that racial feature redundant?


Is there any difference between "She is sitting in back of me" and "She is sitting behind me"? Are they synonymous or are there any different shades of meaning? All the dictionaries that I've looked through only have something to say about the differences in the frequency of usage between American and British English, but not about any differences in meaning.

What's the difference to these expressions, as in "The little girl was hiding in back of the tree" vs. "The little girl was hiding back of the tree" vs. "The little girl was hiding behind the tree"?  In addition, do "in back of" and "back of" have any currency in AE today? Plus, are these idioms safe to use for all proses, even the most formal one?


Let  $f:[0,1]\to \mathbb{R}$, $f(x)=0$ if $x\not\in \mathbb{Q}$ and $f(x)=\frac{1}{q}$ if $x=\frac{p}{q}$, $p,q$ coprime. $p$ integer, $q$ natural.  I want prove that $f$ is Riemann integrable.  I have a doubt. Let $P=\left\{\frac{1}{n},\frac{2}{n},\ldots, \frac{n-1}{n},1\right\}$ a partition.  Now, $U(f,P)=\frac{1}{n}\sum_{i=1}^n M_i=\frac{1}{n} \sum_{i=1}^n\sup\left\{f(x): x\in [\frac{i-1}{n},\frac{i}{n}]\right\}=\frac{1}{n} \sum_{i=1}^{n} \frac{1}{n}=\frac{1}{n} n\frac{1}{n}=\frac{1}{n}\leq \epsilon$ with $n\to \infty$. Therefore $\inf_{P} U(f,P)=0.$  It is correct?...

Let $\displaystyle f: [0,1] \rightarrow \mathbb{R}$ given by   $$f(x) = \begin{cases} 0 & x \notin \mathbb{Q} \\ \\ 0 & x = 0 \\ \\ \frac{1}{q_x} & x = \frac{p_x}{q_x} \in \mathbb{Q} \backslash \{0\}, \ p_x \in \mathbb{Z}, \  q_x \in \mathbb{N}, \ \text{gcd}(|p_x|, q_x) = 1 \end{cases}$$  Is $\displaystyle f$ Riemann integrable?  I am trying to use the equivalent statements $\displaystyle g:[a,b] \rightarrow \mathbb{R}$ is Riemann integrable and $\displaystyle \forall \epsilon >0 \ \exists$ step functions $\displaystyle \rho, \psi$ with $\displaystyle \rho \leq g \leq \psi$ such that $\displaystyle \int_a^b (\psi - \rho) \leq \epsilon$.  I guess that means I would have to somehow show that given $\displaystyle \epsilon$, there exists only a finite amount of $\displaystyle x \in [0,1]$ with $\displaystyle f(x) \geq \epsilon$?   Is it recommended that I consider something else instead? If not, how should I do this?


I have created a excel file with Name,Title,Designation,Department,Faculty,Institute,TelNo,Email id columns I want section wise telephone directory, i.e., We have 16 Faculties. So I want to create a Chapter/section title such as "Faculty of xyz" and under it Section or Subsections like "Department of abc" and below it the names of faculty members with their telephone numbers. Is it possible to create such a Directory?

I have a CSV file (db.txt)like this:  30.0,   0.0,    0.0 60.0,   1.9098, 5.8779 90.0,   6.9098, 9.5106 120.0,  13.09,  9.5106 150.0,  18.09,  5.8779 180.0,  20.0,   0.0   I need to typeset it. My problem is related with the wrong alignment of decimal point and the number of decimals (must be a constant for each column):  \renewcommand*{\dtlrealalign}{r}  \DTLloaddb[     noheader,     keys={x,y,theta},     headers={         \shortstack{$\boldsymbol{\theta_{2,i}}$},         \shortstack{X},         \shortstack{Y}              }   ]{db}{db.txt} \begin{table}[t]   \caption{Database file}   \centering   \DTLdisplaydb{db} \end{table}     Any advice, please?


So im not an python developer but was reading a source code of a python console app which i would like to write it in c# and experiment with it. But i couldn't understand this expression:  result = content[:4] + sig + content[19:]   Can someone explain me what is [:4] and [19:].

I need a good explanation (references are a plus) on Python's slice notation.   To me, this notation needs a bit of picking up.   It looks extremely powerful, but I haven't quite got my head around it.


Suppose that $a$, $b$ and $c$ are positive real numbers and that $a \leq b + c$. By cross multiplying or otherwise, show that  $$\frac{a}{1 + a} \leq \frac{b}{1 + b} + \frac{c}{1 + c}$$  Anyone able to get this to work out? I cross multiplied them but am unable to manipulate it into an expression that verifies the statement.

With $x+y\ge z$ $(x,y,z\ge0)$, prove that: $$\frac{x}{1+x}+\frac{y}{1+y}\ge\frac{z}{1+z}$$  I'm aware that using analytic view this is easy since $f(x)=\frac{x}{1+x}$ is concave in $[0,\infty)$. However I want to prove it using merely algebraic techniques. Is that possible?


Every time I want to install something with terminal it shows this warning message but it continue to install, what's the problem?     dpkg: warning: files list file for package 'linux-generic' missing; assuming package has no files currently installed

I want to install Open JDK or Oracle JDK to my machine but I got an error during installation. The error is:  Selecting previously unselected package oracle-java8-installer. dpkg: warning: files list file for package 'unity-scope-gourmet' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-guayadeque' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-gmusicbrowser' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-manpages' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-firefoxbookmarks' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-gdrive' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-home' missing; assuming package has no files currently installed E: Sub-process /usr/bin/dpkg returned an error code (2)   I searched on Google and try to something for install/reinstall this packages. Finally i try to remove Unity. I faced this error for my every tries. I am using Xmonad. How can I fix this issue?


I came across "$$" expression in shell script, something like this       TFILE=$$  Can anyone tell me its meaning?

I once read that one way to obtain a unique filename in a shell for temp files was to use a double dollar sign ($$).   This does produce a number that varies from time to time... but if you call it repeatedly, it returns the same number.  (The solution is to just use the time.)  I am curious to know what $$ actually is, and why it would be suggested as a way to generate unique filenames.


Problem:  There are 2 girls and 7 boys in a chess club. A team of four persons must be chosen for a tournament, and there must be at least 1 girl on the team. In how many ways can this be done?  Now,the solution suggested by the book is C(7,2)+2xC(7,3)=91 ,Which I understand,But I don't understand why my answer which is C(2,1)xC(8,3) is wrong. Because after choosing 1 girl,There are no more rules,So we should just choose 3 more people.

I was given the following problem to solve:     A committee of five students is to be chosen from six boys and five   girls. Find the number of ways in which the committee can be chosen,   if it includes at least one boy.   My method was $\binom{6}{1}\binom{10}{4}= 1260$, using the logic of choosing $1$ boy, then choosing the rest. This was wrong, as the answer was $\binom{11}{5}-\binom{5}{5}= 461$.  The correct answer's logic was committee with no restrictions – committee with no girls.  Why was my method wrong? Please help...


Let $(G, \cdot)$ be a group, $a,b\in G$ such that $\DeclareMathOperator{\ord}{ord}\ord(a),\ord(b)<\infty$.  Do we then have that $\left|\left<a,b\right>\right|$ divides $\ord(a)\ord(b)$? (Where $\left< a,b \right>$ denotes the subgroup generated by $a$ and $b$)  I managed to show this for the case that $a$ and $b$ commute, however I would be interested if this holds even if they don't.

Let $G$ be a group and let $a,b$ be two elements of $G$. What can we say about the order of their product $ab$?   says "not much":     There is no general formula relating the order of a product $ab$ to the orders of $a$ and $b$. In fact, it is possible that both $a$ and $b$ have finite order while $ab$ has infinite order, or that both $a$ and $b$ have infinite order while $ab$ has finite order.   On the other hand no examples are provided. $(\mathbb{Z},+), 1$ and $-1$ give an example of elements of infinite order with product of finite order. I can't think of any example of the other kind! So:   What's an example of a group $G$ and two elements $a,b$ both of finite order such that their product has infinite order?     Wikipedia then states:     If $ab = ba$, we can at least say that $\mathrm{ord}(ab)$ divides $\mathrm{lcm}(\mathrm{ord}(a), \mathrm{ord}(b))$   which is easy to prove, but not very effective. So:   What are some similar results about the order of a product, perhaps with some additional hypotheses?


If Notepad (the Microsoft Notepad that comes preinstalled with Windows, in my case Windows 7) froze before I had a chance to save the content to a file, is there a way to recover the content? Notepad does not have some kind of "backup" on the hard disk. I don't think in any windows version does notepad keep any data on disk.   It's all in the memory, or if you opened an existing file that has already been stored on disc all the changes are in the memory. So if the task is still there just frozen, the memory should still be there. I got the idea from my first attempt to resolve the issue by "unfreezing" notepad (see ). If unfreezing doesn't work, the problem remains of recovering the data.  Please note, this is a very different scenario form the one stated in the following question:  There the memory is wiped clean because of the reboot, in my case all the data is still in the memory.

I was running NotePad and Chrome when my computer suddenly shuts down.  After reboot, chrome was able to "restore" itself such that I didn't lose any data.  However, how do we "restore" notepad.exe?


Let $Y$ be a subspace of a topological space $(X, T)$. Prove that if $A$ is a closed subset of $Y$ and $Y$ is a closed subset in $X$ then $A$ is a closed subset of $X$  My attempt: Since $Y$ is a subspace of $X$, the open sets are of the form $Y\cap U$ with $U\in T$ and  $Y$ is closed in $X$ implies that $X-Y$ is open and  $A$ is closed in $Y$ implies $Y-A$ is open.  I am really stuck at this point. Can someone please help.

I have a non homework related question from a text and require a nice clear proof/disproof please  Is it true that a subset that is closed in a closed subspace of a topological space is closed in the whole space?  my ideas:  if $H$ is the subset of the topological space $X$  if the subset is closed in the closed subspace, the complement is open in the subspace, which means the complement is of form $U\cap H$ for some $U$ open in $X$  if the subspace is closed the complement is open which means complement of $H=U$ for some open $U$ in $X$  kind thanks


Is it possible to pass a page message to a newly created PageReference, so that this page will display it?  public PageReference doAction() {    PageReference resultPage = new PageReference('/'+id);    resultPage.addMessage(new ApexPages.Message(...));     return resultPage; }   or  public PageReference doAction() {    PageReference resultPage = Page.customPage;    resultPage.addMessage(new ApexPages.Message(...));     return resultPage; }

Is there any way to trigger the display of a page message in the embedding Detail page from the Controller Extension of a Custom list view button?  I create my list view buttons  and as this uses seperate pages per button the page messages created in the Controller Extension seems to land in them and NOT in the displaying detail page.  Page  <apex:page standardController="Contact" extensions="ContactAction_CtrlExt"               recordSetVar="contacts" action="{!doAction}">  </apex:page>   Controller class  public with sharing class ContactAction_CtrlExt {      ...      public PageReference doAction() {        ...        ApexPages.addMessage( new ApexPages.Message(severity, 'THIS WILL NOT APPEAR IN PARENT PAGE') );     }    }


My facebook ad metrics shows me a number of clicks in my ad. Also my google analytics is tracking the facebook ad source, but the number of clicks in my ad is almost 30% bigger than the number of visits that is being tracked by the google analytics from the facebook campaign source.  What am I missing here?

We have a website that we advertise via Facebook, but in Google Analytics only 30-50% of the clicks appear. (The page is not really public yet, so I cannot post a link here)   We already did several test runs and tried different optimizations. Unfortunately none of the optimization resulted in a massive change. (Optimizations like improving page load time, in particular loaded JS like jQuery assets via CDN, etc...)  Right now we have several hypotheses why this happens:   the page is hosted in Virginia, however the site is for Brazil, so latency might be too high in general it takes too long until the page appears, so people might close the page before it's fully loaded it's a one-page app, so it might be slow on old computers too much AJAX, in particular we use Facebook Connect people might use adblockers   We ruled out that Facebook gives us the wrong number of clicks, we already take the number of actual website clicks.  Benchmark results from webpagetest.org using São Paolo/Chrome/Cable:   Load time (First View: 3.9s-6.7s; Repeat View 1.9s-2.8s) First Byte (First View: 0.5s-1.6s; Repeat View 1s-2s) Start Render (First View: 2.3s-5.4s; Repeat View 1.4s-2.2s) Document Complete (First View: 3.9s-6.7s; Repeat View 2s-2.8s) Fully Complete (First View: 5s-8s; Repeat View 2.9s - 3.6s)   (Yesterday we changed the hosting provider, but I think the numbers before should have been similar.)  What could be the problem? To us it is very mysterious, we would assume that the click counts from Facebook would differ from Analytics' numbers by less than 5%. Seeing more than 50% of the users not reaching our website, makes us believe there is a single big problem that we are not aware of yet.


I need to update the grub2 themes. I already removed unwanted entries in menu by editing grub.cfg file. Now I like to update or load the eye catching themes, I want to know whether any Linux application is available for updating themes or we want to do it manually. Please guide the process for both manual and application.

Grub is well Grub. How do I pimp it a bit with some nice themes?


I have the following HTML, how can I retrieve the ID of the input from the tag's name in JavaScript?
                <input type="radio" name="Name[labeled_tags][]" value="01" id="radio_button_01">         Fblabel

Let's say I have an html form.  Each input/select/textarea will have a corresponding <label> with the for attribute set to the id of it's companion. In this case, I know that each input will only have a single label.  Given an input element in javascript — via an onkeyup event, for example — what's the best way to find it's associated label?


I have a bash script that calls various commands and prints some output (both from the called commands themselves, such as git pull, and informative messages generated by the script itself such as Operation took XX minutes.  I'd like to capture the whole output to a file from the script itself: basically I'm trying to avoid the need to call ./myscript.sh | tee file.txt for non-relevant-here reasons.   Basically I'd like to do something like this:  startCapture  git pull  echo "Text"  other-command  endCapture   I also require the output to be printed on my shell while the script is running.  The final goal is to:   run ./myscript.sh without additional shell constructs see the output on the terminal as I do now obtain a file on disk with the whole output   Is this even possible?

I have a bash file that I need to redirect all output to one file, debug log as well as to the terminal. I need to redirect both stdout and stderr to the debug and log it for all commands in the script.  I do not want to add 2>&1 | tee -a $DEBUG for every single command in the file. I could live with | tee -a $DEBUG.  I remember there was a way to do it with something like exec 2>&1.  Currently I'm using something like the following:  #!/bin/bash DEBUGLOG=/tmp/debug exec 2>&1 somecommand | tee -a $DEBUGLOG somecommand2 | tee -a $DEBUGLOG somecommand3 | tee -a $DEBUGLOG   but it does not work. Does anyone have a solution/can explain the cause?


Can someone tell me how to classify the morpheme -ump, such as can be combined with lump,slump, bump, etc.  (It's for a research I'm doing on onomatopoeia.) thanks

I’m referring to the similar definitions of these four nouns – something raised and rounded.  Why do these four rhyming words have similar meanings?  I have not found very specific sources for these words on the  and . Hump is “probably from Dutch homp.” Rump is “from a Scandinavian source,” “from Old Norse rumpr” ultimately from Proto-Germanic “rumpo.” Lump is “perhaps from a Scandinavian source” and finally, Bump is “perhaps from Scandinavian,” “probably of North Germanic origin.”   Could these words come from the same root? Other than the fact that they all might come from northern Europe, the only hint I have in this direction is the following from , tracing the origin of Hump through Dutch, Middle Low German, Old Saxon and Proto-Germanic, to Proto-Indo-European *kumb-, *kumbʰ- (“curved”). Could this PIE root, which is not given in these online sources for any of the other three words, be a common root to all four words? I find myself looking at other –ump words and “seeing” a curved or rounded line: jump (a curved trajectory), grump (a downturned mouth), pump (the action of the pump handle), clump (a rounded clod of earth, not sharp), etc. Am I just seeing this because the words sound similar, or is there something more to my tendency? For example, the  suggests the origin of jump is "perhaps onomatopoeic (cf. bump)" although this view is not echoed on Wiktionary. Is it possible that these words do all share a common root and are simply onomatopoeic variations of each other? Are there other pairs or groups of words like these in English? (Wham! Bam! Ka-blam!) Does     this phenomenon have a name?


I have recently re-installed Windows 7 following a BSOD incident and I have noticed the CPU usage maxing out occasionally when I am not doing very much (not when it has recently started up). When I hear the fans going full throttle I check task manager to see what is working the computer so hard, but nothing is listed that is using more than a few % CPU, yet the overall usage is 100% (or high ninties) e.g.    Does anyone have any ideas on how I can get the the bottom of what the computer is really doing when this happens?

I'm using WinXP, and I notice that in the Task Manager, on the Performance tab my CPU usage is 100%.  But When I go to the Processes tab, and sort by CPU System Idle Process is taking up 90%.  I've double checked that things like AVG anti-virus isn't actively scanning, and that jkdefrag is not defragging.  But I know something is taking CPU cycles, because the machine is very slow.  How do I determine which process is hammering the CPU if it doesn't show in the Process List?


Let $Z=\{(x,\sin(\frac{\pi}{x})\mid 0<x\leq1\}$, and suppose $X=Z\bigcup\{(0,0)\}$ is equipped with the subspace topology. Show that any path in $X$ starting from $(0,0)$ must be the constant path.

Is there a (preferably elementary) proof that the graph of the (discontinuous) function $y$ defined on $[0,1)$ by $$ y(x) =\begin{cases} \sin\left(\dfrac{1}{x}\right) & \mbox{if $0\lt x \lt 1$,}\\\ 0 & \mbox{if $x=0$,}\end{cases}$$ is not path connected?


So let's say I have a project that contains 100 scenes or levels. Each scene contains a token (some coin or diamond) that can only be grabbed once. If the player takes the token in level N and replays level N the token should no longer be there but saved in some sort of wallet when he first grabbed it. What would be the correct way to implement such a system? I'm looking just for a general idea of how this is implemented in most games.

I am currently developing a game in unity and I want to add some sort of saving system that saves the following:  Locked / unlocked level. The amount of money the player has. Items / perks that the player has.  As you can see, the data I want to save is global, and has nothing to do with any specific scene. How would you reccomend save this kind of data? I have heard about the EasySave asset but I don't know if it is the right choice: it is pretty expensive and I belive that there has to be some easier, cheaper (even free) way to save the data. I'll appreciate any answer or consideration.


How safe is it to invest in cryptocurrency? I see bitcoin going up almost every time I look at its market value. How can anyone be sure it wouldn't crash in the future?

I plan to invest a portion of my savings in cryptocurrencies that I understand on a technical level (e.g. Bitcoin and Ethereum). However, otherwise prudent financial advice articles on the internet invariably claim that my decision is unwise. Cryptocurrencies are not commonly seen as a proper investment; they are seen as "risky", "speculative", or even "gambling". I don't understand why cryptocurrency is not considered a proper investment in the same class as real estate, stocks, bonds, and foreign currency. The Bitcoin-USD price volatility probably contributed to the "speculation" and "gambling" labels, but stock market volatility doesn't stop stocks from being considered investment-grade! To reduce risk from individual cryptocurrencies, I could simply hold a large basket of cryptocurrencies instead of just one or two (similar to diversified index funds for stocks).  Why are cryptocurrencies not considered proper investments? Can I make my cryptocurrency holdings "investment-grade" by holding a basket of cryptocurrencies instead of just one or two?


I am trying to copy a character pointer's value to new character pointer. It is giving me Segmentation Fault at line number 8. But i have already initialized my another pointer where i want to copy first pointer's value. Why this error is occurring even if it is (second pointer) not non-allocated memory ?  #include<stdio.h>  int main(){     char *source = "Hey You Boy!";     char *target = '\0';      while(*source != '\0'){         *target = *source;         source++;         target++;     }     *target = '\0';      printf("In Target ->");      while(*target != '\0'){         printf("%c",  *target);         target++;     }     return 0; }

The following code receives seg fault on line 2:  char *str = "string"; str[0] = 'z';  // could be also written as *str = 'z' printf("%s\n", str);   While this works perfectly well:  char str[] = "string"; str[0] = 'z'; printf("%s\n", str);   Tested with MSVC and GCC.


I have a window in an empty space. I need to show another world through that window and also have the camera fly through the window into the new world.  Any tips on how to achieve this effect?

Perhaps a reference video would be needed to show this, but to clarify, merely the portal and its animations appear nearly impossible to create, the frame itself is simple diffusion and optional reflection. Mind this is using cycles.   I though the best way to attain this would be to have the position of the camera changing cause a movement of the portal textures however it has proven futile.  And so I ask, is this possible in Cycles?  EDIT:  My original plan was to use the UV Warp modifier to create the movement effect, with several planes underneath each other to create the depth. However, the way it appears to be a void, another area is the piece I lack.   The frame of the portal, again, is not a problem.  In reference to a comment that referenced a similar concept using a Nether portal that showed the Nether upon the other side, is similar, however there is no need to create another world on the other side, as I want to stay true to the visual mechanics of Minecraft.  Here is an example of the in-game version of what the goal is.


FIXED: I'm going to put it up here, because people keep don't seem to read all the way down and keep telling me this is an exact duplicate of another thread while the solution proposed there (using edge split or auto-smooth) did not fix my issues. In the end I reconstructed the model using the shrinkwrap modifier to cut holes and then manually merge and readjust the vertices of the outside hole for perfect smoothing. Thanks @Cegaton for the video that featured the shrinkwrap modifier.  Images of the reconstruction:       [ORIGINAL POST]  After two Boolean difference operations the model's geometry looked like this:    I guess it won't be a surprise that it resulted in this kind of crappy shading:    I know it's because of the ngons, but I don't know how to best fix or prevent matters. I've tried by making the geometry more complex, by subdividing existing edges and faces, and I've tried by making the geometry simpler, by snapping and joining dead-end vertices onto other ones, while respecting the shape of the model and keeping faces planar. Both these methods still left me with bad shading. I also tried doing the boolean operation with simpler objects, with fewer subdivisions, but that gave me similar issues. Or is my whole approach wrong-headed from the start and I need to go about creating the shape in another way?  PS: the issue is not fixed by using edge split modifier, to be clear.

I tried to manipulate a cube with the Boolean modifier. I tried to cut out an edge of the cube with a cylinder. Also, the shading result looks awful in FLAT SHADING mode, so I turned on SMOOTH SHADING.   Has anyone an idea how to achieve a better result. (I also cut out a Sphere first, this made the result less awful).   I used Blender Internal and rendered with smooth shading for smoothness.  Using flat shading looks okay, except the "round" cutouts :/  Face normals are okay.  First image is smooth shading.    EDIT: User Pisurquatre suggested the EdgeSplit modifier, works perfect to me (Maybe a little tweaking here and there):


For example, I registered myName.com and I also registered the .net, .info, and .org extensions for myName. I'm wondering if it will hurt my SEO to forward these other TLDs to myName.com?

Lets say I have a domain already, for example www.automobile4u.com (not mine), with a website fully running and all.  The title of my "Website" says:    <title>Used cars - buy and sell your used cars here</title>   Also, lets say I have fully SEO the website so when people searching for the term buy used cars, I end up on the second or first page.  Now, I want to end up higher, so I go to the google adwords page where you can check how many searches are made on specific terms.  Lets say the term "used cars" has 20 million searches each month.  Here comes the question, could I just go and buy that domain with the search terms adress, in this case www.usedcars.com and make a redirect to my original page, and this way when people search for "used cars", my newly bought domain name comes up redirecting people to my original website (www.automobile4u.com)?  The reason I believe this benefits me is because it seems search engines first of all check website adresses matching the search, so the query "used cars" would automatically bring www.usedcars.com to the first result right?  What are the downsides for this?  I already know about google spiders not liking redirects, but there are many methods of redirecting...  Is this a good idea generally?


Is it possible to use delete operator on class instance without new operator to deallocate memory? Like this:  Class myclass{public void hi{std::cout<<"hi\n";};}  myclass class1; delete &class1; class1.hi(); //results in error   Thanks

Ignoring programming style and design, is it "safe" to call delete on a variable allocated on the stack?  For example:     int nAmount;    delete &nAmount;   or  class sample { public:     sample();     ~sample() { delete &nAmount;}     int nAmount; }


I'm looking for Minecraft language files to a resourcepack, but I only found the English US one. Where are the another ones?

Where are minecraft languages stored?  I want to add a new language such a pirate speech except for making it my own. I already have my .lang file ready, but do not know what to do with it.  Where can I place this file so it is read by ALL compatable minecraft versions and I can use it?   Also, where can I store (IF POSSIBLE) a copy of   credits.txt end.txt splashes.txt   So it can be in the same language?


Wiki states that: The Stolz–Cesàro theorem can be viewed as a generalization of the Cesàro mean, but also as a L'Hôpital's rule for sequences.  To be precise, Stolz–Cesàro  states that: If $$\lim_\limits{n\to \infty} \frac{a_{n+1} - a_{n}}{b_{n+1}- b_{n}} = \lim\limits_{n\to \infty} \frac{a_{n}}{b_{n}}=k.$$ In contrast L'Hôpital's Rule states that: $$  \lim_\limits{x\to \infty} \frac{f^{(n)}(x)}{g^{(n)}(x)}=  \lim\limits_{x\to \infty}    \frac{f(x)}{g(x)}= k.$$ Although some similarity is apparent, I can't see how one generalizes the other. L'Hôpital's rule is about derivatives of the numerator and denominator when Stolz-Cesaro is about sub-sequences.

I have to give a presentation on the theorem in Real Analysis with a fellow student. While I've looked over the  and verified that, yes, step B does indeed follow logically from step A, etc. and have internalized the proof to the extent that I can replicate it myself on paper, I still feel that I have made little progress as to why this theorem works the way it does, i.e. what is the intuition behind the theorem, such that it should make sense that it follows the way it does. Therefore I ask: what kind of intuition is there about this theorem? It would also be helpful to understand how the theorem can be used effectively in analysis.  I have seen it referred to as a sort of L'Hopital's rule for sequences, which certainly seems to make sense, but I similarly have little intuitive understanding of how that rule works, either.  I am asking this question not only for my personal understanding, but also for the sake of being able to present it in an illuminating manner, such that the rest of the class can also come away with the same sort of intuition of how the theorem works and how it is useful. Any help would be greatly appreciated.  EDIT: I should point out that the formulation of the theorem we are being tasked to prove is the following:  Let $\lbrace a_n \rbrace$, $\lbrace b_n \rbrace$ be sequences, ${b_n}$ strictly increasing and unbounded. Then if $\lim\limits_{n \to \infty} \frac {a_{n+1} - a_n}{b_{n+1} - b_n} = l$ for some $l \in \mathbb R$, then $\lim\limits_{n \to \infty} \frac{a_n}{b_n} = l$ also.


We have mountains of evidence about singularities and how they work, and we have mountains of evidence that the "Big Bang" was the origin of the universe as we know it. But if compressing enough matter into a small space causes an inescapable singularity (i.e., a black hole), why does compressing all matter into a small space lead to a sudden expansion?

Extrapolation of the expansion of the Universe backwards in time using general relativity yields an infinite density and temperature at a finite time in the past.  If the matter contained within our galaxy were concentrated within a small radius wouldn't that lead to the entire universe being a black hole? If so how is it that all the matter of our observable universe could have originated from a region of infinite density?


I want to update my Ubuntu 14.04 system from the terminal and I know that sudo apt-get update && sudo apt-get upgrade are the commands but when I check the update manager kernel updates are still there. Why is that ? and what can I do to update the kernel from terminal.

Just what the title says. The update manager is also asking me to update to Ubuntu 12.10 even when I have the part unchecked that says "Check for new Ubuntu version updates" thing. Is there some way to turn the annoying update manager off?


i need a way to make the countdown decreasing inside the if statement i am stacking in  this problem for more than 3 days .. Don't suggest to me Coroutine cause it will not working in my case cause i am using clones (initiated prefabs)  i know that the countdown will work only one frame if it's inside an IF Statement ... Any Ideas to make it working ...Ty  The game is about cars ... and every instantiated car has a random countdown timer  void Update() {     if(carNumber < cars)     {         SpawnCars();     } }   and this is the spawn  function  void SpawnCars() {     randomSpawnPoint = Random.Range(0, spawnPoints.Length);      randomSpawnCars = Random.Range(0, Cars.Length);      GameObject obj = Instantiate(Cars[randomSpawnCars],spawnPoints[randomSpawnPoint].position, Quaternion.Euler(-90, 180, 0)) as GameObject;      carNumber++;                  obj.gameObject.tag = "select";// + k;      rcf = obj.GetComponent<RayCastForward>();     TextMesh txt = FindObjectOfType<TextMesh>();      time = Random.Range(4, 20);       txt.text = (time - Time.deltaTime).ToString("0");     print(time);     print(carNumber); }   EDIT: time is the timer

i am instantiating prefab cars ... the clones had a random countdown timer with each one off them and its working very well but the its not  decreasing its not counting down the timer is inside the spawn method the spawn method is inside the WHILE loop and the while loop is inside the UpDate() ... i  tried  to move the countdown to Update() but didnn't worked ... any ideas ...Thank You!  void Update() {     p -= Time.deltaTime;           while (carNumber < cars && p <= 0 )         {              SpawnCars();             print(carNumber);             p = 5;                    }  }   and this is the spawn method:   public void SpawnCars() {     if (spawnAllowed)     {         // choose a random strat point 1/6              randomSpawnPoint = Random.Range(0, spawnPoints.Length);         // choose a random car 1/6         randomSpawnCars = Random.Range(0, Cars.Length);         // clone randomly a car(1/6) from a random pre_set-points(1/6)         GameObject obj = Instantiate(Cars[randomSpawnCars], spawnPoints[randomSpawnPoint].position, Quaternion.Euler(-90, 180, 0)) as GameObject;         // carNumber will count how many cloned car          carNumber++;         // destroy the  cloned car after N sec        // Destroy(obj, 8);         // every cloned car will take a tag with it         obj.gameObject.tag = "select" + k;         k++;         rcf = obj.GetComponent<RayCastForward>();         //textCDT         time = Random.Range(4f, time);         TextMesh txt = FindObjectOfType<TextMesh>();   //the Timer:         time -= Time.deltaTime;         coolDown = time.ToString("0");         txt.text = ""+coolDown;      } }   edit: i forgot to tell that the timer  is inside SpawnCars().


I have "Install OS X El Capitan.iso" file. I have burned the image to a DVD and successfully installed El Capitan in the past. Now that my DVD drive is broken, I would like to create a bootable USB Drive out of it. Can this be achieved? If yes, I'd like to know how.

Does anyone have a Terminal command-line recipe for making a new bootable USB flash drive for one of the new MacBook Air's?  Is there a way to dd copy the USB boot device that comes in the box and make the new copy bootable?  I'd like to make a new backup copy of the USB rescue device for my MBA, preferably on a much larger flash drive with room for a backup of some of my working directories.  Added:  And is it possible to make, not just a rescue drive, but a bootable USB drive that will boot a fully updated version of the OS (say 10.6.8 or later)?  If so how on a MacBook Air 11, and how big a USB stick will this require?


'Southwestern Ontario' means , as depicted in the reddened area of  Wikipedia's map below: it includes the , but excludes the  and .    Question: Does Southwestern Ontario contain any parks or wildlife areas that contain roads or trails through which you can drive in a car to explore? .

Meaning of 'Central Ontario': Henceforth, Central Ontario refers to  and the reddened area of  Wikipedia's map (abridged by me) below, which excludes Manitoulin Island.   Central Question: In Central Ontario, are there any national parks or wildlife areas that contain roads or trails on which vehicles can explore the park?  Context: Residents of Toronto, my elderly grandparents desire to behold nature by exploring  an 'authentic' national park or wildlife reserve, one situated truly in the wild and not 1 hour outside Toronto, preferably with natural water bodies. Alas, their feeble health and physician's warnings prevent them from hiking, and limit them to walking only around 15 minutes at a time.  To enable them to perceive nature, my grandparents were thinking of renting an off-road vehicle (with all wheel drive), to drive into the inaccessible interiors of parks (instead of walking all the way), and to stop and walk briefly only to access the most beautiful sites (eg: a scenic water body very remote inside a park).


I tested the following on AIX and it works.  logfile=log.txt echo "Hello" > "$logfile" exec 1>>"$logfile" mv "$logfile" "${logfile}_new" echo "World"   After this script ran the file log.txt_new will contain:  Hello World   I was not expecting it to work because I renamed the file to where stdout was being redirected. Why does it work?  It also works if I mv/rename the directory that contains the log file.

I just renamed a log file to "foo.log.old", and assumed that the application will start writing a new logfile at "foo.log". I was surprised to discover that it tracked the logfile to its new name, and kept appending lines to "foo.log.old".  In Windows, I'm not familiar with this kind of behavior - I don't know if it's even possible to implement it. How exactly is this behavior implemented in linux? Where can I learn more about it?


How can I get around the dependency problem when installing libssl-dev?  The problem:  $ sudo apt-get install libssl-dev Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  libssl-dev : Depends: libssl1.0.0 (= 1.0.1c-4ubuntu8) but 1.0.1c-4ubuntu8.1 is to be installed E: Unable to correct problems, you have held broken packages.     System info:  $ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 13.04 Release:    13.04 Codename:   raring  $ uname -a Linux Compy 3.8.0-30-generic #44-Ubuntu SMP Thu Aug 22 20:52:24 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux     My question looks similar to  - but no, apt-get update does not do a thing for me.

Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


How to remove ubuntu 14.04 dual boot with windows 7 ?

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


Hi Guys currently doing some Numerical Differentiation and I was looking at the different formulas such as 1) forward difference method 2) backward difference method 3) central difference method  $$\frac{f(x+h)-f(x)}{h}$$  $$\frac{f(x)-f(x-h)}{h}$$  $$\frac{f(x+h)-f(x-h)}{2}$$  Now based on using taylor's series, I know we can derive different or higher orders for the derivatives for example if i required $$f''(x)$$  using Taylor's series I know i can add f(x+h) + f(x-h) and obtain the the second derivative using taylor series.  I am trying to derive the third derivative  $$f^3(x)$$ using the taylor's series but   f(x+h)  $$f(x+h) = f(x) + hf^1(x)+h^2f^2(x)+h^3f^3(x)$$  f(x-h) $$f(x-h) = f(x)-hf^1(x)+h^2f^2(x)-h^3f^3(x)$$  This is my confusion to derive the thrid derivative for forward diff $$f^3(x)$$  $$f(x+h) - f(x)-hf^1(x)-\frac{h^2f(x)}{2!} = \frac{h^3f^3(x)}{3!}$$  $$\frac{6}{h^3}[f(x+h) - f(x)-hf^1(x)-\frac{h^2f(x)}{2!}] = f^3(x)$$  where  $$f^1(x) = \frac{f(x+h)-f(x)}{h}$$  and  $$f^2(x) = \frac{f(x+h)-2f(x)+f(x-h)}{h^2}$$  when i substitute i get the following  $$[\frac{6f(x+h)}{h^3} - \frac{6f(x)}{h^3} -\frac{6}{h^2}[\frac{f(x+h)-f(x)}{h}]-\frac{3}{h}[\frac{f(x+h)-2f(x)+f(x-h)}{h^2}]] = f^3(x)$$  And then when i attempt to break this down  $$\frac{6f(x+h)}{h^3}-\frac{6f(x)}{h^3} + \frac{-6f(x+h)+6f(x)}{h^3}+\frac{-3f(x+h)+6f(x)-3f(x-h)}{h^3}$$  I am not sure in term sof evaluating the third derivative if this is correct as i am attempting to do it for the Forward difference method and then for the backward and central difference method.Can anyone help me or clarify please.

Hi Guys currently doing some Numerical Differentiation and I was looking at the different formulas such as 1) forward difference method 2) backward difference method 3) central difference method  $$\frac{f(x+h)-f(x)}{h}$$  $$\frac{f(x)-f(x-h)}{h}$$  $$\frac{f(x+h)-f(x-h)}{2}$$  Now based on using taylor's series, I know we can derive different or higher orders for the derivatives for example if i required $$f''(x)$$  using Taylor's series  $$f(x+h) = f(x)+f'(x)h+\frac{f''(x)h^2}{2!}+\frac{f'''(x)h^3}{3!}$$  $$f(x-h) = f(x)-f'(x)h+\frac{f''(x)h^2}{2!}-\frac{f'''(x)h^3}{3!}$$  $$\frac{f(x+h)-2f(x)+f(x-h)}{h^2} = f''(x)$$  My question is as I am bot confused to define the third derivative when using the Taylor series when making the substitution from the Taylor series and this is my approach then adding both equations $$f(x+h) + f(x-h)$$  $$f(x+h)-2f(x)+h^2f''(x)+f(x-h) = \frac{h^3f^3(x)}{3!} - \frac{h^3f^3(x)}{3!}$$  then I decided to try $$f(x+h) - f(x-h) = hf(x)+hf(x)+\frac{2h^3f'''(x)}{3!}$$  $$\frac{3![f(x+h)+2h(x)-f(x-h)]}{2h^3} = f^3(x)$$  and this is incorrect so I am hoping someone can help me understand defining higher order derivatives when using the Taylor series for these methods.   Essentially I am trying to understand how to attain  $$f^3(x),f^4(x),.. etc $$  etc using the Taylor series


My 2010 MacBook Pro is stuck at the Apple logo and spinner (followed by a circle with a line through it). I accidentally mis-typed and altered the NVRAM setting. (as this sudo nvrm "rd=wrognserver"). I have already tried ⌘ Command⌥ OptionPR, to no avail (but suspect the keyboard is not working, I have ordered a wired USB keyboard, awaiting delivery). Any clues would be helpful.

Well, I know there's an answer to a similar question here: , but this is slightly different.  My system is  running on external drive. Actually on an external drive partition. After I installed Waves plugins I encountered this error for the first time. So I booted in my main system on internal drive and used repair on that partition by sudo diskutil mountdisk force /dev/disk2 because partition didn't show up. That didn't help. So I used diskutil repairvolume /dev/disk2s4 and after repairing it helped and I was able to boot normally. It happened twice and each time at firsrt getiing 🚫 and after repairing a volume I was working fine (I'm running on this system now).  I tried reinstalling macOS – did nothing. I have an old backup that's lacking some files. So I guess, if I backup now it's going to backup the whole drive including system folders errors. Any ideas how to fix this without erasing/restoring onanism?


I am not able to run this Python file from terminal.  I have added the shebang:  #!/usr/bin/env python   at start of the file.    Am I doing something wrong? How can I run this file from terminal?  EDIT:  I guess, this might be helpful.

Trying to get casperjs running on Ubuntu 12.04. After installing it when I run I get:   09:20 $ ll /usr/local/bin/casperjs lrwxrwxrwx 1 root root 26 Nov  6 16:49 /usr/local/bin/casperjs -> /opt/casperjs/bin/casperjs  09:20 $ /usr/bin/env python --version Python 2.7.3  09:20 $ cat /opt/casperjs/bin/casperjs | head -4  #!/usr/bin/env python  import os import sys  09:20 $ casperjs : No such file or directory  09: 22 $ python Python 2.7.3 (default, Sep 26 2013, 20:03:06)  [GCC 4.6.3] on linux2   So Python is present and runnable, casperjs is pointing to the right place and it is a python script. But when I run it I get "No such file".   I can fix it by changing the first line of the casperjs python file from:    #!/usr/bin/env python   to:   #!/usr/bin/python   Result:   $ casperjs --version 1.1.0-DEV   I managed to fix it, but I'm wondering why it didn't work with #!/usr/bin/env python, since that seems to be a normal interpreter line. Do I have something configured wrong?   Here are the steps to get casperjs:   $ git clone git://github.com/n1k0/casperjs.git $ cd casperjs $ ln -sf `pwd`/bin/casperjs /usr/local/bin/casperjs $ casperjs : No such file or directory


I was making a scene and, due to the bad computer I'm making it on, I have to create the render every time instead of going into render view. Suddenly, the render only showed the background, and I tried to figure out why but all of the normal reasons why that would be the case weren't the case (i.e. hidden, in a different layer). I've only been using Blender for about a month, so please go easy on me. (If you'd like to include a critique of the water or plane/B24 liberator in your answer, please do!)  Before:   After:  Render:

This is meant to solve this problem once and for all. What is every reason an object isn't showing up in a render or viewport in when using the cycles render engine?


How do I make a single page landscape 11" x 17" while the rest of the document stays 8.5" x 11" in portrait?

I'm using Microsoft Word 2010. How do I set only the last page of my document to be horizontal? All other pages have to remain vertical.


I'm looking for the name of a short story about family on space flight.  The boy somehow stayed out of suspended animation, possibly out of curiosity.   At the end, with "empty eyes" he answers what it was like.

I'm trying to remember the name of a short story I read about 25 years ago or so. I'd also like to know of any collections it appeared in.   The details I recall involve a family who are embarking on a hyperspace journey. To undertake this journey you have to be put to sleep. One of the children pretends to be asleep, and when the jump is complete the child has gone insane. From the child's point of view the jump lasted for an eternity while in reality it was only a few seconds.


I am trying to find which does more damage per second: The polished silver sword or the trolls bludgeon. The one thing I don't know the frequency of hits from the weapon speeds eg. fast, slow, very slow. so i want to know: How many hits per second does each weapon speed do?

I have a choice currently between the troll bludgeon (12-16 damage, slow) or my silver sword (7 damage, medium speed). Which has a higher average dps?


Let $X_1,..,X_N$ be a random sample drawn from a uniform distribution ${\cal{U}}[\theta-.5,\theta+.5]$. I am trying to find the MLE of $\theta$.  In all other questions posted, I see $\theta$ at least enter the pdf. But it's not the case here. Wondering if there is a way to do it?  Thanks!

$X_1, X_2, . . . , X_n$ are i.i.d. observations from a uniform distribution on the interval $[\theta − \frac{1}{2}, \theta + \frac{1}{2}]$.  Show that any $\theta$ between $X_{max} − \frac{1}{2}$ and $X_{min} + \frac{1}{2}$  maximizes the likelihood, and therefore, can be taken as the MLE.  I am confused...because $f(x|\theta) = \frac{1}{(\theta+\frac{1}{2}) -(\theta -\frac{1}{2})} = 1$ for $\theta-\frac{1}{2} \le x \le\theta+\frac{1}{2}$ and 0 otherwise... Isn't the likelihood function $L(x|\theta) = 1$?  The how can it be maximized between $X_{max} − \frac{1}{2}$ and $X_{min} + \frac{1}{2}$ ?


This is what I get when I run a simple program. bash: python: command not found [Finished in 0.0s with exit code 127] [shell_cmd: python -u "/home/hector/.config/sublime-text-3/Packages/User/print("IAN").py"] [dir: /home/hector/.config/sublime-text-3/Packages/User] [path: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin]

I am using Sublime Text 3 in Ubuntu. The default Python is python2 which Sublime uses when I build program using Ctrl+B. I am trying to run code as, print(f"Player {row[0]} Vertically =")  but it gives error as follows because code is run with default Python File "/home/gd/Desktop/python/python-revision/pp_13_iterators_iterables.py", line 41   print(f"Player {row[0]} Vertically =")                                       ^ SyntaxError: invalid syntax [Finished in 0.0s with exit code 1] [shell_cmd: python -u "/home/gd/Desktop/python/python-revision/pp_13_iterators_iterables.py"] [dir: /home/gd/Desktop/python/python-revision]  However, when I run same program from terminal, using python3 it works as expected. $ python3 pp_13_iterators_iterables.py [1, 2, 1] [2, 0, 1] [1, 2, 1] Vertically Player 1 Vertically =  How can I change default build environment of Sublime Text to Python 3 and build it using shortcut as Ctrl+B? I tried using alias as alias python="/usr/bin/python3.6"  but it didn't work and gave same error as previous.


I am working in JavaFX program. I am trying to jump from my previous fxml file to new fxml file. When I am jumping to my new fxml file, controls are not getting instantiated.  I am getting all these errors:  Caused by: java.lang.NullPointerException at sample.Controllers.StudentDetailsController.init(StudentDetailsController.java:161) at sample.Controllers.KeyMapController.studentResponseEvent(KeyMapController.java:159) at sample.Controllers.KeyMapController.initialize(KeyMapController.java:100)   This is my code to change sceen  try {     FXMLLoader loader = new FXMLLoader();      loader.setLocation(getClass().getResource("scenes/studentDetails.fxml"));     Parent parent = loader.load();     StudentDetailsController controller = new StudentDetailsController();     controller.init(testDetails);     Stage stage = (Stage) ((Node) event.getSource()).getScene().getWindow();     Scene scene = new Scene(parent);     stage.setScene(scene); } catch (IOException e) {     e.printStackTrace(); }

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


I have raster containing 2 bands (NDVI and DEM). This raster was created in SNAP using "Add Elevation Band" option, "DEM Model:SRTM 1sec Grid" to the NDVI product I had generated earlier. I could not find any option in SNAP to make the conversion of this combined product into an ASCII file. There is however one option in SNAP to export the product to a CSV but the result of that process were not as expected. So I switched to QGIS. Here I tried the Raster>Conversion>Translate option, which ultimately uses the gdal_translate tool.   So in QGIS-Translate I could convert the .tif to .XYZ(ascii) but the output had only one band value along with the lat-long for each pixel. I got the warning "Warning 6: XYZ driver only uses the first band of the dataset."  I used the option -b 1 -b 3 to include the bands I want in my output file but still the same warning kept coming.  My gdal_query looks as below,  gdal_translate -of XYZ test-op-1p-ndvi_DEM.tif gdaltranslate-op1DEM.xyz -b 1 -b 3  I tried using the other option in this query like -ot with Byte format (as mentioned in one related question here in GIS-StackExchange) and also by removing the -of XYZ parameter  I have also tried gdal_translate through the OSGeo4W desktop tool but got same warning there too,    After searching hard enough, I could not find anything satisfactory. So now I am trying the long way by generating 2 separate .XYZ for each band and then combine through python script, parsing and combining the 2 columns.  Can anyone please provide any hint or suggestion. Even if someone can link to similar questions in this forum would be really helpful, as i have already tried solutions from many related questions but could have missed something important.  Screenshot of .XYZ with only NDVI values   Screenshot of .XYZ with only DEM values

I have been able to import into QGIS a set of raster topographic maps and the associated DEM raster maps. It registered the two for me. From there I have calculated the associated slope raster map. Now I want to export the data to a CSV file (or similar format) for processing in a program that I am writing. Ideally the data would be structured in a way that would permit me to query for the slope and elevation data for any given point on the map.   If this is possible, then how do I do it?  Specifically, I have been able to export the data (slope & DEM) to two different CSV files. However I would prefer the data in one file if possible.


So there's the problem: I wanted to create a bootable USB from an ISO image BUT I accidentally I did that one on my external hard disks instead of the usb.  Now that drive is 2TB and it was full of picture, files etc. I would like to recover as much as possible from that. Since I'm pretty a n00b with Ubuntu I'm trying to figure out how to use Testdisk (which I've heard it's a very good tool for data recovery). Questions:   is it not possible just to unmount the iso in order to get again access to the other files? Does the mounting "formats" in some ways the rest of the drive? Testdisk asked me to specify the partition table type, what is and what I should answer? There are other possible ways to recover the data? I mean, nothing was "really" formatted and also the iso is not big enough to mess everything up.   Sorry if those questions are out of topic of not so detailed, and thanks for any possible answer.

The first 7GB of a 500GB NTFS partiton was accidentally overwritten with another file. Is it possible to recover some of the data in the remaining 493 GB of the NTFS volume? The partition table is intact. The executed command was:  dd if=file of=/dev/sdc1   Thanks  Edit: My question is different. I overwrite first 7GB of NTFS partition. Other question mostly deals with hardware failures or bad sectors.


Stack overflow is about getting high quality answers quickly.  The way that answers are sorted is intended to help realize that goal.  However, occasionally low quality answers find themselves on the top, when an answer is accepted, but later turns out to be unsupported by the community at large.  For example, the accepted answer to  has -4, while the highest scoring answer has a score of 19.  Without even looking at the contents of the responses, it's probably the case that the information in the accepted answer is dangerously incorrect while the most valuable info for future travelers is hidden further down.  This can amount to a lot of noise before finding value:    In a lot of cases, this happens when a one time user accepts an answer and then leaves, never to be seen of again.  This has its own set of issues addressed in other questions.  However, users who are still active are well primed to help improve answer quality, but currently have no one of knowing that their accepted answer has become dated.  In this particular case, the asker is still an active SO participant:    If prompted, they might be so inclined to revisit their question.  We don't need to pressure people into always accepting the highest voted answer, but in extreme cases they can help improve quality answer visibility without undermining the current sorting system that places the accepted answer at the top.  This would address something similar to what is currently being handled with the reminder:     Have you considered accepting an answer or starting a bounty for this question?   A good threshold might be sending a reminder to the question owner whenever the  badge is earned on a given question.  If they dismiss it, they don't need to be reminded again, but it's a good opportunity to allow active users to reconsider accepted answers that might have become incorrect.  Related to:

I asked a  on stackoverflow at the end of last year for a beta or pre-release product and got the answer I wanted.  3 months later someone else answered the question with the correct answer for a newer release.  This answer got way more upvotes than the one I accepted.  I only noticed this today so changed the accepted answer.  Can I get a notification email when an answer gets say 10 more votes than the one I accepted.  Just to let me know something might be up.


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


I'm trying to change the value of one cell in a 2D python array:  [[0, 1, 2], [0, 1, 2], [0, 1, 2]]   which I generated from  m=3*[[0]*3] for y in xrange(0,3):     for x in xrange(0,3):         m[y][x]=x   I want to replace m[0][0] with 5 so that it looks like  [[5, 1, 2], [0, 1, 2], [0, 1, 2]]   but instead it is  [[5, 1, 2], [5, 1, 2], [5, 1, 2]]   when i use   m[0][0]=5   what's going on?

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


I'm new in this type of sites but I want to be part of the community, I already make a question but I can't vote in it know. I will be very grateful if you can help me with this.

Am I really forced to ask a question before gaining reputation to vote up answers that I find helpful?  I've used StackOverflow for years in my JavaScript development, and I see myself as a pro. But I always find my questions already been asked and answered, therefore never had the need to ask any questions, but I still want to vote up stuff that I find helpful. But I have not enough reputation to do so.


Microsoft Office now recommends changing phrases such as:  "will host all of the"  to  "will host all the"  due to this being more "concise" language. However, to me, their recommendation doesn't sound grammatically correct. Is this recommendation sound?

Is the word "of" optional in this instance? Is either of these considered preferable to the other?        Taste all our delicious treats.   Taste all of our delicious treats.


I know we can use both Present Simple and Present Continuous to describe future actions. But I don't know when to use the correct form.   For example:  We fly to Paris next week.  We are flying to Paris next week.   These sentences both seem correct to me.  Can anyone explain me how to correctly use these tenses?

Here's an example of a short conversation between me and a native speaker via text messages:  A: I'm so exited for this app B: Yeah, me too A: We start tomorrow B: OK   Shouldn't it be "We are starting tomorrow"?!


My mats are 6x9 feet and I want to take pictures at a perpendicular angle from the top so that it is even. As of now I am taking  pictures from the side.  Here is how I am looking to take the picture:    Here is what I'm currently doing, which I don't want:

I am trying to take pictures of small and large rugs. I have Canon 6D with 24-70mm lens. Could you please suggest the best way for mounting the camera to the ceiling, and any other recommendations for my camera/lens setup?  The ceiling has steel supports with height around 12ft (3.6 metres).  There are about 4000 rugs, small and too large. the use case for photos is for uploading in website for customers


I'm currently a Physics major undergrad. I was wondering if you could recommend Statistical Mechanics books. At my university, we work with Concepts in Thermal Physics by Blundell, but I always prefer to have several books to consult before getting to a course.

I learned thermodynamics and the basics of statistical mechanics but I'd like to sit through a good advanced book/books. Mainly I just want it to be thorough and to include all the math. And of course, it's always good to give as much intuition about the material.  Some things I'd be happy if it includes (but again, it mostly just needs to be a clear book even if it doesn't contain these) are:   As much justifications for the postulates if possible, I'm very interested in reading more about how Liouville's theorem connects to the postulates. Have examples of calculating partition functions, hopefully not just the partition function for the ideal gas.