I have following two questions:  1) Why am I getting a NullPointerException at the line when I am calling t.i.hashCode()?   2) In what all scenarios is hashCode() method called and not called? (Does it gets calls only in cases where we are using objects of Hashing related classes?)  o/p  is null.   Exception in thread "main" java.lang.NullPointerException                     at Test.hashCode(EqualsHashcode.java:65)                     at java.util.Hashtable.put(Unknown Source)                     at EqualsHashcode.main(EqualsHashcode.java:20)   import java.util.*; public class EqualsHashcode  {      public static void main(String[] args)     {         //System.out.println("Main Method");         Test s = new Test("bharat",1);         Test p = new Test("bharat",1);         //System.out.println(s);         //System.out.println(p);         //System.out.println(s.equals(p));         Test q = new Test("bharat",2);         //System.out.println(q);         //System.out.println(s.equals(q));         Test r = new Test("bhara",1);         //System.out.println(r);         //System.out.println(s.equals(r));         Hashtable ht = new Hashtable();         ht.put(s,"1");         ht.put(p,"1");     }  }  class Test {   Test t;     String p;     int i;     Test(String s, int j)     {         p=s;         i=j;     }      public String toString()     {            System.out.println(p+".."+i);         return p+" Hashcode is"+p.hashCode();     }      public boolean equals(Object o)     {            if (this==o)         {             return true;         } else if ( o instanceof Test)         {                         t = (Test) o;             if (this.p.equals(t.p) && this.i==t.i)                             return true;             else                 return false;         } else          return false;      }      public int hashCode()     {             System.out.println(t);         System.out.println("Calling hashCode" + " "+ t.p.hashCode()+t.i);         return t.p.hashCode()+t.i;     } }

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


What is the tense of "You should do that."? Also, what about the tense of if-conditionals.

I know that "tense" indicates time. If that is true, then not every sentence can be indicated of its tense.  Please review these sentences:  "If I could go to the market , I must have taken breakfast (by now)." "If this great mountain was given my secret, it would have broken." "If she were tall like you, she would never have asked you to pick those clothes for her."    Here all these sentences have main clauses in past, but I don't know whether past indefinite or not.   Still, these are imaginary conditions, supported by “if”; so can we say that these sentences have no tense?  Some people told me that their roots are in the present as we are indicating the absence of the mentioned conditions implies that the sentence indicates the present continuous, or some other sort of present.   But that sounds strange, as the sentence itself does not narrate the absence of that condition but only the supposition of “if” that were true... so what is the tense. Thnx for all responses. Now i can safely say that this sentence is making use of auxiliary modals in subjunctive mood. Still according to my perspective, it indicates towards a timeless phenomenon( Though no one knows about the future) still its pointing towards a timeless phenomenon, still if someone wants to refer it to a tense, i think its is present indefinite because it indicates that i am not a bird. "If I were" suggests that I am not.Otherwise the sentence itself does not refer to time. And as i have understood English language does not make use of tense only to indicate time, the total sentence structure depends on many thing sand also the mood of sentence changes the total outlook of any sentence. So tense and/ or mood can be understood if they indicate real things rather imaginary ones.  I failed to understand any better through these answers.


I have a backup device set for my transaction log so the sets are contained in 1 file. I have this set to append, is this correct or should it be overwrite in the plan? After the full backup is taken and then the next log backup, I still see additional sets in the file.  Update  Ok I tested this an over writing loses all other sets. So is there a way to purge this after a full backup has been taken from a plan?

I have a database that is set to the 'Full' recovery model, and I'm creating a maintenance plan to backup the Transaction Log every 15 minutes. A full backup is then taken once every 24 hours.  I was wondering: will the maintenance plan for the transaction logs create a lot of different files every 15 minutes, or will it by default append to the same file for 24 hours?  Also: what is preferred? I couldn't find anything on this subject (or maybe I was Googling the wrong words).  Thanks for any pointers anyone can give me.  EDIT: I also see that the checkmark "Verify backup integrity" is OFF by default. Is there a risk with turning it on? It seems to be that it should be on by default, so is there a reason for not using this?


When I open up natuilus ( the default ubuntu file manger), the icon does not appear in my task manager so when I want to go back to that same session, I simply cannot. I wonder if this is a known problem. using 16.04.

I'm experiencing this behaviour on 2 separated machines (in a virtualbox vm and physically installed on another laptop):  Sometimes after I start the Files Gnome application - its corresponding button disappears from the Unity Launcher couple seconds after it's started. So if I minimize the application - I have no chance to close the application rather than killing its process with kill.  That's how it looks like:    Has anyone else experienced it? Is it a bug or some tricky configuration option?  If it's a bug - where should I report it?  PS: I've filed a bug for that


I have this code:  $hackers = array ('Alan Kay', 'Peter Norvig', 'Linus Trovalds', 'Larry Page');   I want to delete 1st two items and later want to get back just deleted items in an array

Is there an easy way to delete an element from an array using PHP, such that foreach ($array) no longer includes that element?  I thought that setting it to null would do it, but apparently it does not work.


I'm trying to execute the lxd command from the /snap/bin directory. I have added it to the user .bashrc, .zshrc, and /etc/environment. When I echo $PATH I get the following output: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/games:/usr/games:/snap/bin:/home/duke/.local/bin:/home/duke/snap/bin  I can execute the command with my user permissions, however it just tells me I need to run the command in root. So if I try with sudo I get the following result: sudo: lxd: command not found                                          Which prompted me to add the /snap/bin directory to the root path, .bashrc, and .zshrc. After doing so I can access the command via the root account but my intention was to use my own account rather than the root account to execute the lxd command. I rather hoped that adding the snap/bin directory to the root path would solve my problem, but it doesn't. In fact the only way I can use those commands with the sudo prepending said command it by directly addressing the command, i.e: sudo /snap/bin/lxd  Which isn't satisfactory. How do I get the commands located in the bin directory under the snap directory to work as any other command under '~/.local/bin' or '/usr/bin' would? Thanks in advance.

I need to run something as sudo without a password, so I used visudo and added this to my sudoers file:  MYUSERNAME ALL = NOPASSWD: /path/to/my/program   Then I tried it out:  $ sudo /path/to/my/program [sudo] password for MYUSERNAME:    Why does it ask for a password? How can I run/use commands as root with a non-root user, without asking for a password?


How can I turn the model items into a one string in C#?   IEnumerable<MyModel> test = _table.entity.ToMyModel();   Now my model is like  return new myModel {     Item1 = "This is ",     Item2 = " a test ",     Item3 = " to make one sentence" }   Now I want to do something like this to turn the first row of the IEnumerable into a sentence.   string xyz = test.First().toString();    I would like xyz to = "This is  a test  to make one sentence"

So for viewing a current object's state at runtime, I really like what the Visual Studio Immediate window gives me.  Just doing a simple  ? objectname   Will give me a nicely formatted 'dump' of the object.    Is there an easy way to do this in code, so I can do something similar when logging?


The table cards were A,K,K,8,3. All four suits were on the board. Player one had A,8. Player two had A,3.   Is this a split pot?

In Texas Hold'em poker, there are some cases where a particular card, often called kicker, acts as a tiebreaker between players to determine who wins the pot, or if the pot has to be shared.  For some combinations such as three or four of a kind, there is no doubt: the kicker is the 5th card of the chosen combination, and determines the winner.  Example     Alice has 7 and 10   Bob has 7 and K   On the board are 7, 7, 2, 3, 4   In that case, both have a three of a kind. But because Bob has a king and Alice only a 10, he wins.  Most of poker websites explaining the rules clearly mention the role of the kicker applying to three of a kind and double pairs. But much fewer say something about colors, straights and full houses, and I found many contradicting answers. I also asked the question to some used online poker players and they also gave me contradicting answers.  I have tried to search for official tournament rules, but most of them only explain what happens with bad behaviors, bad deals, incorrect or confusing betting, showing cards when you shouldn't, acting when it's not your turn, etc. without mentioning subtleties about combinations at all.  To simplify my question, I will take three examples; I think it's better to start with examples before getting to the general answer if one exists. So, what's happening in the following 3 examples? Could you give a more generalized answer?  Example 1 - Flushes     Alice has 2♣ and 3♣   Bob has 4♣ and 5♣   On the board are 6♣, 8♣, 10♣, 2♥, 5♦   Contradicting answer 1: it's a tie, because the highest card included in the flush is the 10, which everybody chooses to include in their 5 showdown cards. Contradicting answer 2: Bob wins, because he has the greatest private card that is part of the flush  Example 2 - Straight     Alice has 6 and K   Bob has 6 and J   On the board are 4, 5, 7, 8, 10   Contradicting answer 1: it's a tie, because the greatest card in the straight is the 8 for both Alice and Bob Contradicting answer 2: Alice wins, because she owns an extra king, compared to the jack of Bob  Example 3 - Full house     Alice has 3 and 7   Bob has 3 and 6   On the board are 3, 3, 2, 2, 5   Contradicting answer 1: it's a tie, because one is supposed to choose only five cards to make a combination, and a full house is already five cards. There couldn't be any kicker, and thus their showdowns are strictly equals. Contradicting answer 2: Alice wins because of her extra 7, compared to the 6 of Bob  Thank you very much for your answers.  Note: I'm unable to post next to you, so I edit my own post; strange not be able to answer to an answer.  Ok, So if I summarize what you are saying :   In the flush case, Bob wins because at some point, their hand differs. Technically, I can continue comparing the highest private card to decide who wins. I had it correct. In the straight case, if the highest card of the straight is public, then it's technically always a tie, no matter what the players had as second private card (asuming that only one of the two cards was part of the straight). In a full house if both players have the same triplet and the same pair, it's always a tie, no matter what the players had as second private card (assuming again that only one of the two was part of the full house).   Please confirm me that what I summarized is correct.  Thank you for your answer.


For each of the following, give an example of a sequence of functions $f_n(x)$ that converges to f  A. uniformly but not in the mean square sense.  B. in the mean square sense but pointwise nowhere.  I know that for part A the domain of the function cannot be bounded. Please don't just repeat the definition of what it means to converge uniformly, in the mean square sense or pointwise.  I'm looking for clues on how to choose a $f_n(x)$ that matches the conditions

For each of the following, give an example of a sequence of functions $f_n$ that converges to f  A. uniformly but not in the mean square sense.  B. in the mean square sense but pointwise nowhere.  I know that for part A the domain of the function cannot be bounded but other then that I'm not sure how to go about the problem


Problem:      If $G$ is a group in which $(ab)^i = a^ib^i$ for three consecutive integers $i$ for all $a,b \in G$, then $G$ is abelian. If we assume the relation $(ab)^i = a^ib^i$ for just two consecutive integers can we conclude that $G$ is abelian?    Thank all!

Given an example of a non-abelian group $G$ satisfying $(a \cdot b)^i=a^i \cdot b^i, \forall a, b \in G$ for two consecutive integers.   This is question 5 from Herstein Page 35. I have proved that conclusion holds for three positive integers.Thanks.


So, I have a Stack Exchange account. When I first created it a couple of years back, I used my "Google" credentials. Fine. Then late last year I began work with a company which uses Atlassian Crowd to manage IDs and logins, and at some point my Stack Exchange account must have become associated with my id at that company. Now my Stack Exchange account is inaccessible.  But it does exist.  Is there some way to reconnect to my Stack Exchange id?

I accidentally posted a question without being logged in. Is there a way to associate that question with my account?   For more information, visit "" in the .   a.k.a. How can you link a registered account to a cookie-based account? a.k.a. How do I merge an unregistered account with a registered account a.k.a. Merging users a.k.a. How do I associate anonymous questions I’ve asked with my registered account? a.k.a. Is there a way to claim an unregistered user? (in case anyone searches with those terms)


If (using amsthm) I have a proof which ends on an equation, and after that some text goes on, I have something like:   text / (bit of space) / equation / (bit of space which looks huge because there is nothing in the line with qed) / empty line with the qed / (bit of space) / further text.  Here's a MWE ...  \documentclass{scrartcl} \usepackage[UKenglish]{babel} \usepackage[T1]{fontenc} \usepackage{amsmath} \usepackage{amsthm}  \begin{document}  \begin{proof} Here is a bit of text which explains how the last step will work. The last step will only be some easy equation or some property with no need to write text between this and the q.e.d. \begin{equation*} \int\limits_1^\infty f(t) g(t) dt = \Biggl[ \frac{a^b}{c^d} \Biggr] = \infty  \end{equation*} \end{proof} And then, some other text goes on...  \end{document}   ...and here's a picture of it:    What I would like to have is the qed to move to the blue position (that is the "lower border" of the equation line).  I tried inserting \vspace{-...} which - no matter if I put it in the equation, between the equation or the proof - will just move the text of after the proof upwards (yellow arrow) while leaving the rest unchanged. I also tried \qedhere in the equation's line, which is almost what I would like to have but then the qed is centered in the equation line (indicated in red).

Description of the problem My problem is this. For the proof of a math theorem i use the proof environment of the package amsthm. It adds a \qedsymbol in the last line of the proof, but if the proof ends with a displayed formula the qedsymbol appears in the next line leaving an unwanted blank space. The documentation of  teaches to fix this problem placing the command \qedhere after of the displayed formula but inside of the appropriate environment. This works well if the formula is of one line like \[ax^2+bx+c=0.\qedhere \]  but if the proof ends in a matrix, or cases with a "great height" the qedsymbol is fixed in the baseline at right and it this looks higher than expected (for my taste). The result is showed in this MWE \documentclass{article} \usepackage[width=7cm]{geometry} % Only for reducing space in this MWE  \usepackage{amsmath} % For `bmatrix` \usepackage{amsthm} % For `proof` environment \begin{document} \begin{proof} And this proof ends with \[ \begin{bmatrix}     1 & 0 \\     0 & 1 \\     0 & 0 \end{bmatrix}.\qedhere \] \end{proof} \noindent Text \end{document}  that produces  What I want I'd like something like  with the qedsymbol aligned with the bottom of the matrix. Is this possible?


I have a 6yr granddaughter that has encopresis. It's very hard to watch her mom ( a single, working mom) deal with this every day. The little one tries but it is a constant struggle. With doctor visits and different medications it still goes on. It is good to know that there is a diagnosis but with everyday life it is an on going battle. After reading many of the comments on line ,I do feel we are "Blessed" to have a little one that really tries. The problem that I see is the different schedule of each day. My daughters job (different hours) and a busy life in general are very frustrating. I am very Greatfull that "this" is the only health problem that this little one has... however I wish there was a magic pill.I would appreciate any support or suggestions.

Our son (now nearly 6.5 years old) has problems with potty training for years now. (The long history is described here:  ).  Remarks:  We are in regular contact with a doctor specialized in such problems and her diagnosis is "encopresis with obstipation".  We still have those problems, at least every second day on average he is soiling between 1 and 7 underpants. That's ok for us, but the main problem is that when it happens, he does not try to clean himself immediately or tell the kindergarten teachers or us to help him, but very often he just ignores it and continues playing/"working"/whatever he does and often even does not admit it if he's directly asked if he has dirty underwear.  We think that this makes things even worse, as it smells for sure and other people notice it and the other kids are making fun of him for that reason.  But although he is very clever and comprehensible in other matters, it happens very often, that he tries to hide it and continue as if nothing had happened.  That makes it very frustrating for his parents and we are not sure how to handle it, as every attempt to "motivate" him acting on it immediately has failed - positive motivation as well as negative one (negative consequences).  We know that this is a very sensitive and difficult topic - more than ever as because we had a lot of arguments and hot discussions with him in the past. But it feels wrong to just let him do what he wants (and at worst run around the whole day with his smelling pants) - also as cleaning him(self) is much easier and faster as long as it is "fresh" ...  Any hints are appreciated.  In autumn, he'll go to school, which might make things even more complicated as there will be nobody any more who feels responsible for helping him clean himself...    Additional remarks:  I am not sure, why he so often refuses to tell us directly, when he soiled his pants. Some ideas (maybe it is often a mixture of several reasons or even something else...):   He does not want to interrupt his play/activity He does not want that other people notice it (however we do everything to help him and to avoid that others notice it, if he tells us) He sometimes might be so concentrated on his activity, that he really does not notice it directly Maybe he did not tell it us for some of the above mentioned reasons and then is ashamed that he did not tell it directly and tries to ignore or hide it Maybe he's trying to ignore it Defiance - some days ago he said, the more often we remind him to "tell us as soon as it has happend", the less he would do so... I decided and promised to him to not mention it again for some weeks. The months/years before, we (parents) had reminded him several times a day to tell us - especially before "critical" situations, where it would be especially difficult to clean him or where the "damage" might be significant   I asked him, if there are situations, where he feels, that he must go to the toilet but would rather keep playing/crafting/doing what he currently does. He said something like "not many", but maybe he just says what he knows is best for him ... I'm not sure.  There are, however, also times when he tells us... we had one such "accident" in public transportation, where he directly told us that there was poo on his seat (shock), it was so much that it had even "jumped" out of his pants. Thanks to his quick reaction, we could clean it and search a place where to clean him.


I want to change a string literal into all-uppercase one. Here is my code:      // a and b are the same literal      String a = "Test";     String b = "Test";     // now I want to change all b's letter      // into uppercases, but fail.     b.toUpperCase();     System.out.println("a = " + a + ", " + "b = " + b);     // print: a = Test, b = Test      String c = "Test1";     System.out.println("c = " + c + " , c.toUpperCase() = "                 + c.toUpperCase());     // print: c = Test1 , c.toUpperCase() = TEST1      // change letters of "Test" literal      // into uppercase and success     System.out.println("Test".toUpperCase());     // print: TEST   My question is:     1. b can't be changed into uppercase one, but c and "Test" can. Why?  What I know is:     1. a and b reference to the same object in string pool.     2. String is immutable, but it seems not relevant to this question.

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


I just delete all php and mysql and installed it again. but in PHPMyadmin i still get:  Your PHP MySQL library version 5.1.69 differs from your MySQL server version 5.5.39. This may cause unpredictable behavior.   There are my full spec list:  [root@**** ~]# php -v PHP 5.4.31 (cli) (built: Jul 25 2014 07:41:53)  Copyright (c) 1997-2014 The PHP Group Zend Engine v2.4.0, Copyright (c) 1998-2014 Zend Technologies [root@***** ~]# rpm -qa | grep php php54w-5.4.31-1.w6.x86_64 php54w-xml-5.4.31-1.w6.x86_64 php54w-mcrypt-5.4.31-1.w6.x86_64 php54w-mysql-5.4.31-1.w6.x86_64 php-tcpdf-dejavu-sans-fonts-6.0.089-1.el6.noarch php54w-cli-5.4.31-1.w6.x86_64 php54w-mbstring-5.4.31-1.w6.x86_64 php-php-gettext-1.0.11-3.el6.noarch php54w-pdo-5.4.31-1.w6.x86_64 php54w-tidy-5.4.31-1.w6.x86_64 php-tcpdf-6.0.089-1.el6.noarch phpMyAdmin-4.0.10.1-1.el6.noarch php54w-common-5.4.31-1.w6.x86_64 php54w-gd-5.4.31-1.w6.x86_64 php54w-bcmath-5.4.31-1.w6.x86_64  [root@**** ~]# rpm -qa --qf '%{name}-%{version}.%{release}.%{arch}\n' php\* mysql\* | sort mysql55w-5.5.39.1.w6.x86_64 mysql55w-libs-5.5.39.1.w6.x86_64 mysql55w-server-5.5.39.1.w6.x86_64 php54w-5.4.31.1.w6.x86_64 php54w-bcmath-5.4.31.1.w6.x86_64 php54w-cli-5.4.31.1.w6.x86_64 php54w-common-5.4.31.1.w6.x86_64 php54w-gd-5.4.31.1.w6.x86_64 php54w-mbstring-5.4.31.1.w6.x86_64 php54w-mcrypt-5.4.31.1.w6.x86_64 php54w-mysql-5.4.31.1.w6.x86_64 php54w-pdo-5.4.31.1.w6.x86_64 php54w-tidy-5.4.31.1.w6.x86_64 php54w-xml-5.4.31.1.w6.x86_64 phpMyAdmin-4.0.10.1.1.el6.noarch php-php-gettext-1.0.11.3.el6.noarch php-tcpdf-6.0.089.1.el6.noarch php-tcpdf-dejavu-sans-fonts-6.0.089.1.el6.noarch   Can anyone tell me what i can do to upgrade my php-mysql lib?  Note when replacing      [root@**** ~]# yum replace php-common --replace-with=php54w-common Loaded plugins: fastestmirror, replace Loading mirror speeds from cached hostfile  * base: mirrors.dk.telia.net  * epel: mirror.proserve.nl  * extras: ftp-stud.fht-esslingen.de  * rpmforge: mirror.nl.leaseweb.net  * updates: mirror.informatik.hs-fulda.de  * webtatic: us-east.repo.webtatic.com Replacing packages takes time, please be patient... Error: Package 'php-common' is not installed.

When i run the following in my console:  [root@****~]# mysql -u root -p -e 'SELECT VERSION();' Enter password: +-----------+ | VERSION() | +-----------+ | 5.5.39    | +-----------+   Which should be the correct version.  However when i enter my PHPMYADMIN on my server it has the following specs:  Server: Localhost via UNIX socket Program: MySQL Programversion: 5.1.73 - Source distribution   So which version is the correct one and how do i make sure that the database is running on 5.5?  Note  I have already restarted sql several times without any changes


I don't quite understand why /opt is recommended for 3rd-party software. I have to use sudo when I run my programs from /opt via the command line. Doesn't that provide a security risk since sudo allows the program to run as super user?  I am also having trouble adding a .desktop file to a program in /opt. For example if I have a .jar file in opt I have to run it with sudo java -jar name.jar to run the java program, but sudo & gksudo do not seem to work when in a .desktop file, so I can't execute the program from my launch menu without going through the command line.  Where should untrusted software be installed?  Where should applications that need a .desktop be installed?  Is there a way to make .desktop files run the application in /opt?

Every time I read the tips for installing an SDK, IDE, some extension and so on, it says, that I should unpack them in /opt folder. Why do I need to do that?   When I was installing Ubuntu, I read that I should set only 10-20 GiB for the / file system and remaining space set for /home. So should I extend the space for root folder, or leave all stuff at /home? Is there any difference?


I'm trying to download a file from a linux server i'm already connected to. I know you can use scp to connect to and pull down a file from a host, but that requires still being on local. I could scp the file back to my local machine, but the local machine is not accessible from the host.  Is there a way to just pull down the file you are already looking at? Something like:  From the host  $ download <THEFILE>   This would really just be more convenient than having to go back out to my local terminal than scp the file. Instead you could just say "grab this one" Done.  I suppose the client would have to know what to do with the file. And i'm pretty sure "terminal.app" does not have a default downloads folder. So perhaps this is not possible.  BTW I'm connect from a mac to Debian.

If I'm logged in to a system via SSH, is there a way to copy a file back to my local system without firing up another terminal or screen session and doing scp or something similar or without doing SSH from the remote system back to the local system?


Let $\lambda$ be a nonzero real constant. Find all functions $f,g : \mathbb R \rightarrow \mathbb R$ that satisfy the functional equation   for all $x,y \in\Bbb R$:   $$f(x + y) + g(x-y) = \lambda g(x) f(y)$$   I tried this:  $y=0$ implies $f(x)+g(x)$=$\lambda g(x)f(0)$. Here we have two cases depending on $f(0)$:   $f(0)=0$ or $f(0) \neq 0$.   If this is true, what next?

The D'Alembert functional equation is $f(x+y)+f(x-y)=2f(x)f(y)$. Let $f:\mathbb{R}\rightarrow\mathbb{R}$ satisfy the functional equation for all $x,y\in\mathbb{R}$. It's well known that $f$ is of the form $f(x)=\frac{E(x)+E^∗(x)}{2}$, for some $E:\mathbb{R}\rightarrow\mathbb{C}$. How can I use this functional equation to solve the following problem?     Let $\lambda$ be a nonzero real constant. Find all functions $f,g:\mathbb{R}\rightarrow\mathbb{R}$ that satisfy the functional equation $f(x+y)+g(x-y)=\lambda f(x)g(y)$   for all $x,y\in\mathbb{R}$.


I have problem with error LNK2001: unresolved external symbol.  I have a class CThread split to CThread.h and CThread.cpp  In CThread.h i have included boost/thread/tss.hpp, i have also 2 class:  CThreadLocalStorageSlot and  CThread : public CThreadLocalStorageSlot (derived).  in class CThreadLocalStorageSlot i have:  static boost::thread_specific_ptr ThreadLocalStorage_;  but in linking time i have:  1>CThread.obj : error LNK2001: unresolved external symbol "public: static class boost::thread_specific_ptr CThreadLocalStorageSlot::ThreadLocalStorage_" (?ThreadLocalStorage_@CThreadLocalStorageSlot@threads@2V?$thread_specific_ptr@VCThread@threads@@boost@@A)  Why ? i have included boost file which is responsible for TLS so i have definition of thread_specific_pt.  Any sugestion ?  Best regards

Can anyone explain why following code won't compile? At least on g++ 4.2.4.  And more interesting, why it will compile when I cast MEMBER to int?  #include <vector>  class Foo {   public:       static const int MEMBER = 1;   };  int main(){       vector<int> v;       v.push_back( Foo::MEMBER );       // undefined reference to `Foo::MEMBER'     v.push_back( (int) Foo::MEMBER ); // OK       return 0; }


Before the upgrade I was using gnome on Ubuntu 16.04 with lightdm and it worked fine. After upgrading to Ubuntu 18.04 I switched to gnome gdm3. On the first day I could login to my user account, configure gnome and so on. However on the next day when I tried to login for the first time, the login screen just comes back again and when I try it for a second time it just freezes. Can someone help me with this problem?  In advance thanks for help.  UPDATE: I switched back to lightdm and it works just fine. However I would still like to use gdm3 because I like it more. How could I do this?

My Ubuntu is stuck in a login loop when trying to enter my desktop. When I login, the screen gets black and soon after that the login screen comes back.   I've read that the problem might be caused by an error depending on the graphics, here's my graphics card: ATI Radeon 7670M


I'm dealing with unicode stuff in my DB. I have a data field defined as varchar(max), and I'm preventing user to save unknown characters in this field, like "≤" for example (all unicode above U+00FF). While doing so, I found that some characters if sent to be saved in this field would be displayed as "?", so I thought that all unicode characters above "U+00FF" will all be displayed like this, but then I found that "U+201B" which is "‛" is displayed "?" but the next character "U+201C" which is "“" is displayed as "“".  Can someone please explain to me why is that?  Update: Sorry if I was not clear, but I do not want to convert to nvarchar, I want to keep my field as varchar.  What I need to understand is why a character like "‛" is displayed as "?" in a "varchar" field while the next unicode character "“" is displayed properly?

Is it just that nvarchar supports multibyte characters? If that is the case, is there really any point, other than storage concerns, to using varchars?


Let $a = \sqrt{2+i}$ and $K$ is the splitting field of minimal polynomial of $a$ over $\mathbb{Q}$. Prove that $Gal(K/\mathbb{Q})$ is $D_4$.   I find the minimal polynomial of $a$ is $p(x)=x^4-4x^2+5$ and its   roots are $\sqrt{2+i},-\sqrt{2+i},\sqrt{2-i},-\sqrt{2-i}$. Let $b=\sqrt{2-i}$. So the splitting field of $p$ is $K=\mathbb{Q}(a,b)$. Also by Eisenstein's criterion to $p(x-1)=x^4 - 4 x^3 + 2 x^2 + 4 x + 2$ with the prime 2 we can conclude, $p$ is irreducible over $\mathbb{Q}$. Thus $[\mathbb{Q}(a):\mathbb{Q}]=4$. Also $b\not\in\mathbb{Q}(a)$ (since if it were then $\sqrt{2+i}\cdot\sqrt{2-i}=\sqrt{5}$ would also be in $\mathbb{Q}(a)$), and minimal polynomial of $b$ over $\mathbb{Q}(a)$ is $x^2-2+i$. Thus $[\mathbb{Q}(a,b):\mathbb{Q}]=[\mathbb{Q}(a,b):\mathbb{Q}(a)]\cdot[\mathbb{Q}(a):\mathbb{Q}]=2\cdot 4=8.$ Now since $K$ is the splitting field over $\mathbb{Q}$ of a separable polynomial, $K/\mathbb{Q}$ is Galois. Hence $|Gal(K/\mathbb{Q})|=8$. Hence the 8 automorphisms are $$a\to \begin{cases}a\\-a\\b\\-b\end{cases}\quad\text{and}\quad b \to \begin{cases}b\\-b\end{cases}.$$ But there is no automorphism of order 4. Then how can the Galois group be $D_4$?  Can somebody correct me what I am missing?

Let $a = \sqrt{2+i}$ and $K$ is the splitting field of minimal polynomial of $a$ over $\mathbb{Q}$. Prove that $Gal(K/\mathbb{Q})$ is $D_4$.   I find the minimal polynomial of $a$ is $p(x)=x^4-4x^2+5$ and its   roots are $\sqrt{2+i},-\sqrt{2+i},\sqrt{2-i},-\sqrt{2-i}$. Let $b=\sqrt{2-i}$. So the splitting field of $p$ is $K=\mathbb{Q}(a,b)$. Also by rational root theorem, $p$ is irreducible over $\mathbb{Q}$. Thus $[\mathbb{Q}(a):\mathbb{Q}]=4$. Also $b\not\in\mathbb{Q}(a)$, and minimal polynomial of $b$ over $\mathbb{Q}(a)$ is $x^2-2+i$. Thus $[\mathbb{Q}(a,b):\mathbb{Q}]=[\mathbb{Q}(a,b):\mathbb{Q}(a)]\cdot[\mathbb{Q}(a):\mathbb{Q}]=2\cdot 4=8.$ Now since $K$ is the splitting field over $\mathbb{Q}$ of a separable polynomial, $K/\mathbb{Q}$ is Galois. Hence $|Gal(K/\mathbb{Q})|=8$. Hence the 8 automorphisms are $$a\to \begin{cases}a\\-a\\b\\-b\end{cases}\quad\text{and}\quad b \to \begin{cases}b\\-b\end{cases}.$$ From this how to conclude $Gal(K/\mathbb{Q})$ is isomorphic to $D_4$?  Thanks


Two varieties of apple      Two varieties of apples      Two varieties of an apple   Is there any difference between these. Which one should be preferred by a native speaker?

can anybody tell me which one of these is the correct one? I have been searching all over the internet but I have still got no answer.  Types of books Types of book


Essentially I'm trying to obtain something like  (without the f(x) bit), but with custom labels, which I can't seem to do.  \documentclass{article} \usepackage{amsmath}  \begin{document}  \begin{align*} \begin{cases} x+y &= 3 &&& \text{5} \\ x-y &= 1 &&& \text{6} \\ \end{cases} \end{align*}  \end{document}   But it just doesn't work.  I additionally tried the numcases solution in the link, but it seems like I can't manually tag it.  Here is my attempt with the empheq package:  \documentclass[preview]{standalone} \usepackage{amsmath,empheq} \usepackage{cases} \begin{document}  \begin{empheq}{align*}  \begin{cases} x+y &= 3 \tag{5} \\ x-y &= 1 \tag{6} \end{cases} \end{empheq}  \end{document}   The problem over here is that it shows only a (5) next to both the equations somewhere vertically in the center, not a (5) for one equation and a (6) for the other ;P

As much as I have tried, it doesn't seem possible to use separate labels when using a casesconstruction (from the amsmath package).  Ideally, I would like to be able to write something like  \documentclass{article} \usepackage{amsmath} \begin{document} \begin{equation} f(x)=\begin{cases}   1&x\geq0\label{positive}\\   0&x<0\label{negative} \end{cases} \end{equation} \end{document}   and later refer to both cases at different places. What would be the best way to achieve this result?


I tried rename isolinux.cfg and isolinux.bin to syslinux.cfg and isolinux.bin, respectively. Then, I renamed isolinux (file) to syslinux. But, when i opened syslinux, the file is empty. Can anyone solve this issue for me, pls. Thanks a lot!!

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


This is a somewhat subjective question, but I suspect that it might have a satisfying answer, so I'm going to ask anyway.   LaTeX is a tool for typesetting text. There are lots of packages, such as TikZ and pgf, which permit a user to produce graphical elements inside of a LaTeX document. On the other hand, you could create all your graphics with an external program, and include it in the document in an appropriate way.   There are certain situations where it is obvious to use an external program (a complicated plot or a photograph, for instance). And there are certain cases where you really should use something compatible with LaTeX, for instance if your images need to be typeset alongside text in some way which is not possible by simply including the image directly in the document.   My question is: as an experienced TeX user, how should you decide when to use a LaTeX package versus an external tool for creating graphics? This is obviously subjective, and it depends on your particular application. But what properties of your application should you consider when deciding whether an image is suitable or unsuitable for production in LaTeX?   Again, this is an obviously subjective question - but I suspect that there may be an answer which is mostly in 'the spirit' of what LaTeX is 'meant to do'.

What are the benefits of using tools like pgfplots or tikz directly in LaTeX compared to importing PDF/PGF generated by say matplotlib?   believed that the main reason is to match the plots with the rest of the document. It also mentioned that no other plotting packages from R or python can generate graphs that have the same high image quality as those generated by pgfplots in LaTeX directly, but no examples or reasons were given. Is there evidence to back up this claim?    Another related question is that, is there any reason for exporting a plot to PGF instead of PDF?  said that the reason is PGF will generate the whole graph in LaTeX while importing to PDF even with  will only use LaTeX for the text part of the graph. But if the main reason for plotting in LaTeX is that we can match the plots with the rest of the text document, usetex exactly does that.  My current adopted approach to producing PDF documents with graphs is (i) generate graphs using tools like matplotlib or other plotting packages in a scientific programming language so that I can do computations before plotting or plot repetitive graphs; (ii) export to PDF files and use usetex if I want to match the font with my document; (iii) import the PDF files using \includegraphics and make final adjustments.  This seems to work out just fine and I didn't notice any image quality issues or graph not matching with the rest of the document.   So are there any other reasons to use native plotting utilities like pgfplots in LaTeX that I overlooked?


I am opening a pop up VF page as 'render as pdf'.I have created a button Save and on click on save i am closing the pop window and saving PDf to opportunity.  Issue  When i am saving the code when calling the savePdf method without rerender and oncomplete.Its saving the attachment and i am able to open the attachment in opportunity without issue.When i am using either using rerender or oncomplete i am able to save the attachment but it says ".'Failed to load document'"  Its been a week i am stuck please help.  <apex:form>   function myClose(){      self.close();     window.opener.location.href="/{!$CurrentPage.parameters.Id}";      //you could also use self.close();         }  <apex:pageBlock mode="maindetail" id="thePb">          <apex:pageBlockButtons >         <apex:commandButton value="Save to Opportunity" action="{!savePdf}" oncomplete="myClose();"  />        </apex:pageBlockButtons>       <apex:pageMessages />       <iframe height="600px" id="Page" name="InvoicePDF" src="/apex/GenerateQuotePDF?id={!parentId}" width="100%"></iframe>      </apex:pageBlock>    </apex:form>   Class  public void savePdf() {      PageReference pdf = Page.GenerateQuotePDF;     pdf.getParameters().put('id',parentId);      pdf.setRedirect(true);     // create the new attachment   Attachment attach = new Attachment();      // the contents of the attachment from the pdf     Blob body;          body = pdf.getContent();      attach.Body = body;     // add the user entered name     attach.Name = 'Opportunity'+ '.pdf';       attach.IsPrivate = false;     // attach the pdf to the account     attach.ParentId = parentId;     attach.ContentType = 'application/pdf';     insert attach;     }

I have created a VF page and used "render as pdf"  <apex:commandButton value="Save to Opportunity" action="{!savePdf}"  />   Its working fine when i am using above line without rerender and oncomplete but when i am adding rerender or oncomplete it is not working.I am able to save the PDF in attachment folder but when i am trying to open its showing  "Unable to load document"  Even if i remove oncomplete and use Rerender then also its saving the attachment in Attachment object and when i view ,it is not loading and says "Unable to load document"      <apex:commandButton value="Save to Opportunity" action="{!savePdf}"  oncomplete="myClose();"/>   Javascript Code  function myClose(){      self.close();     window.opener.location.href="/{!$CurrentPage.parameters.Id}";  }   Class Code  public void savePdf() {      PageReference pdf = Page.GenerateQuotePDF;     pdf.getParameters().put('id',parentId);      Attachment attach = new Attachment();      Blob body;     body = pdf.getContent();     attach.Body = body;     attach.Name = 'Opportunity'+ '.pdf';       attach.IsPrivate = false;     attach.ParentId = parentId;     attach.ContentType = 'application/pdf';     insert attach;     }     Please help..


The movie was about a girl who seemed normal, she had a brother (I think they were twins but not sure). She gets sick or is injured and is taken to the hospital. They take blood from her and it turns out to be blue.   Eventually, it is revealed that she is an alien princess and was brought to Earth for safe keeping and is not related to her family. In the end, she leaves and goes back to her planet. It's kind of an old movie, from around the 90's.   Also, I think there was an elderly woman (might be her neighbour or grandmother), who was also an alien and was her protector.

I'm trying to find a tv-series/mini-series that I viewed as a teenager, probably in the 90s, possibly late 80s.  A pair of siblings (twins as I remembers) grow up in a nice neighbourhood. One day an old lady moves in next door.  Soon after, at a birthday the sister gets roller skates and is accidentally hit by a car. When taken to the hospital the doctors find that she doesn't seem to be human (not the right number of organs or something like that).  I can't remember the exact story after that, but it turns out that sister is actually an alien while the brother is a normal human. The neighbour is an alien as well sent to protect the girl. They are at some point attacked by light sabre wielding aliens (looking like big red bears on two legs and made of energy).  As I remember it ends with most of the family (at least the brother and sister) leaving the earth and as the sister leaves she turns into her alien form (lots of white shining light).  I don't think it is US made, possibly Canadian, Australian or from the UK.


So I know that $\mathbb{Q}[x]$ is a P.I.D. Does this mean that I only have to find where $x^2-r$ is irreducible over $\mathbb{Q}[x]$? I have tried approaching this by doing the following: $x^2-r$ can be written as $(x-\sqrt{r})(x+\sqrt{r})$ and thus would be irreducible for all $r$ for which this is not an rational polynomial. Am I thinking about this correctly?

Let $K$ be a field and $f(x)\in K[x]$. Prove that $K[x]/(f(x))$ is a field if and only if $f(x)$ is irreducible in $K[x]$.   How to prove? I really have no idea... Thank you a lot.


I have a sql command  SELECT A.*,        K1.AD CONTACTAD,        K1.SYD CONTACTSYD,        KR.AD KURUM,        K2.AD SUPERVISORAD,        K2.SYD  SUPERVISORSOYAD,        K3.AD REQUIRERAD,        K3.SYD REQUIRERSOYAD FROM          TD_ACTIVITY A,        KK_KS K1,        KK_KS K2,        KK_KS K3,        KK_KR KR WHERE  A.INS_CONTACT_PERSON = K1.ID    AND A.SUPERVISOR =  K2.ID    AND A.REQUIRERID = K3.ID     AND A.INSTITUTIONID = KR.ID   I want to combine CONTACTAD and CONTACTSOYAD into one variable like CONTACT.How can i do that?

What is the string concatenation operator in Oracle SQL?    Are there any "interesting" features I should be careful of?    (This seems obvious, but I couldn't find a previous question asking it).


I am creating designs for an app as part of my uni work. I have Windows and because I have Windows I am unable to get the San Francisco font as it's only available on Mac.   What is the best font on Photoshop that looks similar as the San Francisco Font?

I'm doing all graphic design in a startup company of some friends, and a major part of our product is developing an app that should run on everything after iPhone 4. So after some researching (I have basically zero UI design experience) I figured we should use the San Francisco font for the app.  If I understand correctly Apple allows using the font for development purposes. However the  only has an iOS version, and I'm a Windows user, which means I can't use it.  I managed to get the font from other sources, installed it, but it doesn't appear in either PS or AI. I also installed it on a different PC with a different Adobe CS version but that didn't work either.  I'm considering using Helvetica Neue instead, but it would be great if we could use San Francisco.  What options do I have?


Is it possible to use Ubuntu apt sources on Debian 10? Also is it possible to use Debian apt sources on Ubuntu? After saying that, is this recommended?

This question was asked previously, however the answers in this question are intent to tell why that is a poor idea.    No actual answer is actually provided, due to the actual issue at hand being tangential. So for the daring, how do you add Debian experimental repo to Ubuntu?  Thanks.


So, I have a package "com", which consists of two sub-packages "Common" and "Model1". The Model1 contains a class Model which I am trying to import in the Servlet2 class, which resides in the Common package. I compile the Model class first which stays fine, but the Servlet2 class doesn't and comes up with an error saying "package com.Model1 doesn't exist"  Here's the Model class:   package com.Model1;     import java.util.*;    **public** class Model{         public ArrayList<String> getBrands(String color){             ArrayList<String> brands=new ArrayList<String>();             if(color.equals("amber")){                 brands.add("Jack Amber");                 brands.add("Red Moose");             }             else{                 brands.add("Jail Pale Ale");                 brands.add("Gout Stout");             }             return brands;         }     }   Here's the Servle2 class:  package com.Common; import javax.servlet.*; import javax.servlet.http.*; import java.io.*; import java.util.*; import com.Model1.Model; public class Servlet2 extends HttpServlet{     public void doPost(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException{         res.setContentType("text/html");         PrintWriter out=res.getWriter();         out.println("Coffee selection advice
");         String c=req.getParameter("color");         Model m=new Model();         ArrayList result=m.getBrands(c);         out.println("
Got coffee color "+c);         Iterator it=result.iterator();         while(it.hasNext()){             out.println("
 Try: "+it.next());         }     } }   I just can't seem to figure out how to sort this out. Edit: Realised that default modifier is restrictive, but even making it public doesn't seem to work.  I am using notepad++ and I hope this works as the  Minimal, Complete, and Verifiable example:   package com.common; import com.model.*; public class TheClassIWantToImportInto { public static void main(String[] args){ System.out.println("Testing 1"); TheClassIwantToImport obj=new TheClassIWantToImportInto(); obj.testFunction(); } }   The second class:  package com.model; public class TheClassIWantToImport{ public void testFunction(){ System.out.println("testing function"); } }   Both the .java files are in the same folder "C:\Program Files\Java\jdk1.8.0_161\bin"   Using the following commands in this order: javac -d . TheClassIWantToImport.java (Works fine) javac -d . TheClassIWantToImportInto.java (Error: package com.model doesn't exist)

In Java, are there clear rules on when to use each of access modifiers, namely the default (package private), public, protected and private, while making class and interface and dealing with inheritance?


I just accidentally scrolled the size in my browser (FF24.2.0) and I noticed that the graphics in the stack exchange network (meta, se, android, code golf as far as I can see at least) don't scale and get blurry instead.  Before:   After:   I hope you can see the difference, if not try it for yourself (ctrl + scroll in most browsers). Even the upvote and downvote arrows get a bit blurry. I am an absolute beginner on the topics of graphics and I would not know the first thing about how to change this stuff, but I wanted to share my confusion.   Is there a particular reason this is not implemented? Is it just not possible? Or has this been answered before and I simply did not find it trough search?

I think that Stack Exchange could optimize the Stack Overflow logo on top of the page for high-resolution displays.  Moreover I think that svg-Files are a better solution for simple icons like upvote or down vote, which will look sharp on all devices and often have even a smaller size than png-files.


For suspended users, badges are not shown in their user cards at all. They only show "1" with their avatars and usernames, as if they are new users.  Why is this?

My account has been , besides the following restrictions:  an account will be locked at 1 reputation the user page will have a visual indication that the account is in timed suspension, and for how long the account holder will be unable to vote, ask, answer or comment  What else does timed suspension prevent me doing? For example, can I still edit my own posts or delete content? And what is a network-wide suspension?


i am making Gui using qt designer and python.I have two classes on demo.py and demo2.py which are on the same directory/folder.when button clicks on demo,i can show demo2 and hide demo using OOP composition like down below. But then i am so confused why i can't hide demo2(like this down below). This is demo.py  From demo2 import Ui_Form Class Ui_For(object):     def log(s):         s.U=QtGui.QWidget()         s.x=Ui_Form()         s.x.setupUi(s.U)         s.U.show()         Form.hide()     def setupUi(self,Form):         '''the things that are going to be stated here are the Qlabels(QtGui.Qlabel),Qline edit,the button that connects to method log also,which is working good and other things of this window just like the qt designer write it''' If __name__=='__main__':     import sys     app=QtGui.QApplication(sys.argv)     Form=QtGui.QWidget()     ui=Ui_For()     ui.setupUi(Form)     Form.show()     sys.exit(app.exec_())   And this is demo2  Class Ui_Form(object):       def oy(o):           ui.U.hide()#this the the one bringing error       def setupUi(self,Form):           '''And the rest of the code(there is push button here that connects to method oy,and it works good'''   When i go to demo2 widget,when i push a button and connect to method oy,"name 'ui' is not defined" error comes.But why?  Things i tried:  1.def oy(o):        o.x=3        print(getattr(o,'x'))#works great and gives me 3 as expected  But if i did this instead,`  print(getattr(ui.x,'x'))#i get "name 'ui' is not defined" error   Why is this?isn't 'o' the same as 'ui.x' in this case?

Given the following code, what does the if __name__ == "__main__": do?  # Threading example import time, thread  def myfunction(string, sleeptime, lock, *args):     while True:         lock.acquire()         time.sleep(sleeptime)         lock.release()         time.sleep(sleeptime)  if __name__ == "__main__":     lock = thread.allocate_lock()     thread.start_new_thread(myfunction, ("Thread #: 1", 2, lock))     thread.start_new_thread(myfunction, ("Thread #: 2", 2, lock))


I have a simple script to print color text in terminal which I've directed to log file too.  #!/bin/bash  echo -e "\033[01;32mGreen color" > ~/Desktop/color.log   When I run from terminal cat color.log, it prints with green color but when I open file with gedit it shows as  [01;32mGreen color   Is it possible to redirect with color in gedit?

I run a script in terminal and the output printed in the terminal I also save in a text file. How can I display that text in Gedit colored similar to what I can see in the terminal? I thought there could be a plugin. Update I might not have been as clear as I planed, so I would like to see similar coloring changes in the plain text file as appears in terminal, not for shell scripts but if I have an error message (e.g. compiler error) than those line to be differentiated from other printouts in terminal. $ rosrun my_pkg my_node >> terminal_printout Update 2 My gedit version is 3.10.4 ii  libgtksourceview-3.0-1:amd64   3.10.2-0ubuntu1 amd64 sared libraries for the GTK+ syntax highlighting widget ii  libgtksourceview-3.0-common    3.10.2-0ubuntu1 all common files for the GTK+ syntax highlighting widget


I was reading Hanhn-Banach separation theorem and it is written that      " Since $A$ is convex ,open subset of a normed $\mathbb K$-linear space and  f is $\mathbb R$-linear and continuous so $f(A)$ is an open interval."   Since A is convex f(A) becomes an interval but why open?  Please someone help. Thank you..

Let $E$  be a real normed space and $\varphi \in E'$, $\varphi \neq 0$.   Suppose that $A \subset E$ is an open convex not empty subset.   Show that $\varphi(A)$ is an open interval.   Since $A$ is connected and $\varphi$ is continuous,  $\varphi(A)$ is an interval. How could I show that $\varphi(A)$  is open?   I tried to apply the geometric form of Hahn Banach theorem but it didn't work.  I appreciate if you could give some hints. Thanks.


In British English should it be "Rockstar Games' products" or "Rockstar Games's products" to make it possessive?  I would also like to check if the same rule applies if the company name's first word was an adjective    eg. Happy Games  "Happy Games' office" or "Happy Games's office"?  The rule for American English would also be good to know but not essential.   Any help would be greatly appreciated. Thanks  (I apologise for any other grammatical errors or poor use of English I may have made in the phrasing of this question.)

What is the possessive of a noun ending in ‑s?  Are these both right, or is the second one wrong?   the boys' books the boss' car


Kinematic time dilation or else named constant velocity time dilation is an apparent time dilation effect but with real consequences on how we measure time and our everyday life like the GPS satellites which loose in average 7μs in time each day compared to clocks on the surface of the Earth due this Special Relativity (SR) kinematic effect. At the same time they gain time about 45μs due the gravitational time dilation effect  These two opposite effects must be accounted for 45-7= +38μs per day, a total amount of time dilation the clocks on the satellites are going relative ahead in time (faster) compared to the clocks on the Earth surface and compensation must be applied so all clocks are in synchronization. We know from experiments for certain, that acceleration affects matter slowing down at the molecular scale vibrations and therefore has a physical effect on matter and also on tick rates of clock time measuring devices from the mechanical, electronic to atomic clocks. Therefore gravitational time dilation has an actual physical effect on matter. This above, includes also biological clocks and the aging process of living organisms. A man on Jupiter would age slower than a man on Earth, assuming he/she is immune to the hostile environment of Jupiter :) I am curious about if this is also the case for the SR constant velocity time dilation phenomenon and it actually affects matter independent of frame of reference? Since the velocity is constant in this case I expect no any forces to be present on the moving matter. Therefore the tick rate of the clock must not be affected by the constant velocity and the measured time must flow at a constant pace. Which means the kinematic SR time dilation effect is not a matter phenomenon effect but an apparent time measurement information sharing effect of relative moving clocks due the finite speed of light and their different positions in space. The time measured on the clocks is not shifted only the information of the measured time shared between the two observers is shifted in time. Are there any experiments that can show that SR time dilation has an actual effect on matter? A quite simple experiment would be according to the above information to compensate a GPS satellite for a year only for the gravitational time dilation (i.e. clock on satellite runs +45μs faster per day) and do NOT compensate for the whole year for the kinematic SR time dilation effect (i.e. clock on satellite appears to run -7μs slower per day). According to the above information at the end of the year the clock on the orbiting GPS satellite would lack in time about 365x(-7μs)= -2.55 ms. Bring the satellite down to Earth from orbit to stationary position and read out its clock time. If the clock on the stationary satellite would then found to be lacking around -2.55 ms within the error bars of this experiment then this would conclusively prove that SR constant velocity time dilation has an actual physical effect on matter and is not just an apparent relativity effect!

It is said that we can verify time dilation by flying a very accurate clock on a fast jet or spaceship and prove that it registers less time than the clocks on earth. However, the clocks on earth would be moving relative to the clock on the spaceship, and since time always dilates and never goes faster regardless of the direction of relative motion,  the clocks on earth should register less time than the clock on the spaceship.  Is this true? Whenever there is a fast-moving object such as a rocket do all clocks on earth really become slow?  If the rocket with the clock landed after moving at relativistic speed, would its clock and the earth's clock again show the same time since during its travel both appeared slow to each other?  Or is all this just an illusion, ie. the clocks just appear to be slow to each other but in actually run at normal speed, and neither is behind when the rocket actually lands?


How I can remove myself from some Stack Exchange sites, but keep my profile? (For example, I subscribed to some sites just for curiosity; I just browsed without posting or replying.)  I found a delete option but I am afraid to click!   Would it be possible also to unsubscribe from sites where I have been active?

Is there any way to remove individual SE accounts for particular SE sites?  So in other words, say I want to keep my current Stack Overflow account just like it is.  But say I want to delete my account on Server Fault so that it no longer exists and doesn't show up in my SE/SO profile.  Is there any way to do that?  Recap: Keep current login (and certain Stack Exchange sites) but remove particular SE sites' membership for my particular login.  Does that make sense?  Current Accounts Me - StackOverflow Me - SuperUser Me - ServerFault  Desired End Result Accounts Me - StackOverflow Me - SuperUser  Where the desired end result accounts will be the same user (Me) with the persistent questions/answers/reputation/etc.


this one is abit complex.. i need to edit a file that contains lines that have 5 ":" to differentiate.. what i want is to Regex remove anything before 4 ":" and keep what ever is left on that line.. example:  DATA:1000:031:6566:3180:sdhfdsd  DATA:cuoleL  DATA:000:45:133:37081:fsdfsd  DATA:jhh0:70165:50:687:csdhg  DATA:236:93438:34:1ds:dsdbhz  now for this example in line 1 i want to get only "3180:sdhfdsd" and delete whatever is before it i.e "DATA:1000:031:6566:"  and as you can see line 2 doesnt have 5 ":" so the search skips line 2..  please reply... thanks again community!

I don't really understand regular expressions.  Can you explain them to me in an easy-to-follow manner?  If there are any online tools or books, could you also link to them?


I am looking to use the "Sim Settlements" mod for Fallout 4, but I can't seem to get past 20 settlers. Is the settlement limit fixed based on any factors? I understand Charisma is a part of the equation and that it's 10 + your Charisma modifier, but I'm looking to make a metropolis, I can't be running around adventuring in gear that looks like I came out of a thrift store.  The ideal situation is to have 40 settlers where I can have a large metropolis of generated houses.   Is the settlement limit 20 people and without vanilla charisma gear are there any ways to remove it?

I've got two settlements on the go that I'm paying attention to - Sanctuary and the Starlight Drive In. Both of these settlements have radio towers and beds and all resources in the green however they appear to have stopped growing at 10 people in each settlement even though happiness is above 80 and I've got 15+ beds at each location.  What is the maximum number of people that will join a settlement?


I have a String as vsc-nigulp-25.00.00-200.tar , I have to get two set of outputs as vsc-nigulp and 25.00.00-200 from the given string.  What Regex conditions would be giving these two set of outputs?


Functions with the same derivatives  Besides, $f(x)=e^x$,  what other non-zero functions are the same as their derivatives no matter how many times the derivative is taken?

I was wondering on the following and I probably know the answer already: NO. Is there another number with similar properties as $e$? So that the derivative of $\exp(x)$ is the same as the function itself. I can guess that it's probably not, because otherwise $e$ wouldn't be that special, but is there any proof of it?


I've got a problem. I'm attempting to make a Farenheit to Celcius calculator, and when I do the fraction part of math, it kinda doesn't work. It's either 0 or 1.  private void toCelcius_Click(object sender, EventArgs e) {     double F = double.Parse(temperatureBox.Text);     double fm32 = F - 32;     double fraction = (9 / 5);     double newTemp = fraction*fm32;      temperatureLabel.Text = newTemp.ToString(); }   I've been using 100 as my test number, and everytime I send 100 to the textbox, it returns 68. It should be somewhere around 30ish.  Currently the program only senses the fraction as a 1. I tried using decimal instead of using double, but that breaks the newTemp problem. I tried using float, but got same results as a double. I have no freaking idea whats going on but it's very frustrating.  If anyone knows how to fix this, I'd be very thankful.  EDIT: Facepalm it's been such a long time since I've used doubles, forgot I needed to have the .0 after each number.

How do I divide two integers to get a double?


A few months ago I was randomly chosen for Google's 'foobar' challenge (a coding challenge that Google offers to random individuals based on coding related search history). I got through a few of the stages, but got to one I didn't understand. There was a time limit so I'm no longer able to submit an answer (i.e. this isn't a do my challenge for me sort of question), but I would still like to understand the challenge.  What I don't understand about the challenge is less how I would implement a solution in a coding language, but more what it is even asking me to do. This complicates my dilemma of figuring out where to post my question. Would I just post it to Stack Overflow, and if so what tags would I use? What site would be best for this kind of question?

There seems to be more than a few computer science/programming Stack Exchange networks (is that the correct term?). Stack Overflow, being the first, has by far the most users, questions, and answers.  What is the reasoning for creating the others, and are there clear guidelines for which kinds of questions should be posted? I can see a large amount of potential overflow, many cases of people not getting a good answer to their question, because the person who has the answer isn't browsing that particular network at the moment.  I understand that they were probably created for organizational purposes, but wouldn't it almost make more sense to just have them as categories under Stack Overflow, keep them separated but still connected, instead of making people have to create multiple 'account's, one for each network?  I am sure there was a very good reason to break them up, but as someone that is new to SE, it can be somewhat intimidating to decide which one to post in to ensure you get a good answer. For example, if I am a computer science student, my first instinct might to be to post in the computer science network, until I see that it literally has 1% of the users as the Stack Overflow network, which still seems to be for programming/computer science related questions.  So my second instinct would then to be to post it into the Stack Overflow site on the basis that I have a significantly higher chance of my question being seen and getting a good answer. Then I notice that there is also a 'programmers' network, and I don't even begin to know where that fits in. I, and I am assuming most people, will probably just post on Stack Overflow to be safe.  My question is, other than the short little description blurb of each one, is there a clear cut set of guidelines which what each network is intended for, what kinds of questions should go to each one, and is anything being done to encourage people to post in these newer, smaller (more specialized?) networks as opposed to just posting in big daddy Stack Overflow?  Now again, this is for computer science/programming/"why isn't this code doing what I want?" related questions, I am not saying that if I had a question about Linux or WordPress or something I would have the same confusion.


I ran different commands. Maybe I have also corrupted many things.  But I do not see any sort of error or crashes so far. So my main question is how do I know that my pc is healthy and there is nothing wrong in it?! I want to try all "Safe" commands that you guys probably know and see if something is wrong or not. Kind of like "Debugging my PC" as smooth as possible. Especially focusing on dpkg case. And other cases if you know.

I tried to install a package and it did, and it appears to work just fine. However when I installed it I got several warnings about packages being missing.  dpkg: warning files list file for package '...' missing, assuming package has no files currently installed.   Since it is just a warning and it appears to work anyway, I assumed that it doesn't matter, but I would like someone to confirm that.   The packages that are missing are ones that I uninstalled on purpose because they were non-essential and took up a lot of room.  EDIT: Package is tzdata. Using dpkg -i on a .deb file to install. And the above is essentially the entire warning. Just instead of ... it lists packages. python2.7-minimal, libsqlite3-0, libaprutill-dbd-sqlite3, python-minimal`  EDIT: "What exactly did you do?" I ran the command   dpkg -i tzdata_2017b-2_all.deb   to install the package tzdata.  "What did you want to achieve?" I wanted the package to install.  "What happened instead? Did you encounter any warning or error messages?" The package installed and worked fine. However, the above warning appeared for the above packages.  I cannot copy and paste since this is occurring on a separate server. But I will rewrite it here:  dpkg: warning files list file for package python2.7-minimal missing, assuming package has no files currently installed. dpkg: warning files list file for package libsqlite3-0 missing, assuming package has no files currently installed. dpkg: warning files list file for package libaprutill-dbd-sqlite3, assuming package has no files currently installed. dpkg: warning files list file for package python-minimal, assuming package has no files currently installed.   I am not looking for a fix. I am just curious if dpkg giving me a warning in this type of situation actually matters. Again the program works anyway and nothing else on my system needed those packages.


I am trying to build a website/community around 3 types of content;  Problems (I get sunburnt and really hot in summer) Ideas (A hat with a built-in fan that protects you from the sun and keeps you cool at the same time) Implementation (Here's a link to an online store that sells solar-powered hats with fans)  The notion that Problems can spawn ideas to solve them is intuitive to me (and hopefully to the user), but I'm struggling to find a better word for the implementation (ie. the tangible thing that makes the idea happen). Note that this concept doesn't have to be a product as in the example above, it could be Here's a schematic I came up with for building a hat with a fan built into it. For context, this is for  designed to foster innovation and collaboration, so understanding by a wide range of speakers is essential. I think the word "Implementation" is not intuitive, as it won't be clear to the user that an implementation follows from an idea. Some synonyms I've considered myself are;  Product - the implementation may not be something that is actually sold or marketed, it could be something as simple as life-hacks. Solution - I'm concerned this might imply that "Solutions" are the thing that follows from "Problems", whereas that's already used by the concept of an "Idea" Outcome - too vague and doesn't intuitively follow as the implementation of an "idea".  What's a better synonym for "Implementation" here?

Looking for a succinct way of describing the act of solidifying an idea into reality. "Building [idea] out" seems too generic but I'm trying to avoid a long winded, step by step explanation of the process.  Any ideas would be greatly appreciated. Thanks!


I have  a select  select distinct     min(trunc(ALL_SUBS_DAY.CHARGE_AMT * SUP.SHARE_USAGE, 4)) + (ALL_SUBS_DAY.CHARGE_AMT - sum(trunc(ALL_SUBS_DAY.CHARGE_AMT * SUP.SHARE_USAGE, 4))) as CHARGE_AMT from table names;   when I try to run it I get not a single-group group function. If I do it like this  select      min(trunc(ALL_SUBS_DAY.CHARGE_AMT * SUP.SHARE_USAGE, 4)) + (ALL_SUBS_DAY.CHARGE_AMT - sum(trunc(ALL_SUBS_DAY.CHARGE_AMT * SUP.SHARE_USAGE, 4))) as CHARGE_AMT from table names group by SUBS_DAY.CHARGE_AMT, SUP.SHARE_USAGE;   it works. Wasn't distinct supposed to work like group by? Do I really need to list every single column or is there a way not to do it?

I learned something simple about SQL the other day:  SELECT c FROM myTbl GROUP BY C   Has the same result as:  SELECT DISTINCT C FROM myTbl   What I am curious of, is there anything different in the way an SQL engine processes the command, or are they truly the same thing?    I personally prefer the distinct syntax, but I am sure it's more out of habit than anything else.  EDIT: This is not a question about aggregates. The use of GROUP BY with aggregate functions is understood.


Repeating the question from the title:  Question. Let $(a_i)_{i=1}^{\infty}$ be a sequence. How to show that $\liminf_{n \rightarrow \infty} ≤ \limsup_{n \rightarrow \infty}$?  So far I've only managed to show that the inequality holds in one specific case, that is, the case where $\limsup_{n \rightarrow \infty}$, $\liminf_{n \rightarrow \infty}$ are the elements of sequences $(a_{i}^{+})_{i=1}^{\infty}$ and $(a_{i}^{-})_{i=1}^{\infty}$, respectively (in this case the proposition holds, since for arbitrary $N,M ≥ 1$, we have $\sup(a_i)_{i=N}^{\infty} ≥ \inf(a_i)_{i=M}^{\infty}$, even if $N ≠ M$). I've tried to generalize by using contradiction, but it led me nowhere. More concretely, if for the sake of contradiction we assume that $\liminf_{n \rightarrow \infty} > \limsup_{n \rightarrow \infty}$, then it must be the case that $\liminf_{n \rightarrow \infty} > a_n$ for all $n≥N$ and some $N$ (this is the result from the previous exercise in the textbook). This doesn't lead to any contradiction though, since there are sequences where limit inferior is larger than all elements of the sequence past a specific point (e.g., consider the sequence $0.9,0.99,0.999,\cdots$; limit inferior in this case is $1$, which is larger than any element of the sequence)

I am stuck on proofs with subsequences. I do not really have a strategy or starting point with subsequences.   NOTE: subsequential limits are limits of subsequences  Prove: $a_n$ is bounded $\implies \liminf a_n \leq \limsup a_n$   Proof:  Let $a_n$ be a bounded sequence. That is, $\forall_n(a_n \leq A)$.  If $a_n$ converges then $\liminf a_n = \lim a_n = \limsup a_n$ and we are done.  Otherwise $a_n$ has a set of subsequential limits we need to show $\liminf a_n \leq \limsup a_n$:  This is where I am stuck...


Is there anything in the Python standard library that will properly parse/unparse strings for using in shell commands? I'm looking for the python analog to perl's String::ShellQuote::shell_quote:  $ print String::ShellQuote::shell_quote("hello", "stack", "overflow's", "quite", "cool") hello stack 'overflow'\''s' quite cool   And, even more importantly, something which will work in the reverse direction (take a string and decompose it into a list).

When using os.system() it's often necessary to escape filenames and other arguments passed as parameters to commands.  How can I do this?  Preferably something that would work on multiple operating systems/shells but in particular for bash.  I'm currently doing the following, but am sure there must be a library function for this, or at least a more elegant/robust/efficient option:  def sh_escape(s):    return s.replace("(","\\(").replace(")","\\)").replace(" ","\\ ")  os.system("cat %s | grep something | sort > %s"            % (sh_escape(in_filename),               sh_escape(out_filename)))   Edit: I've accepted the simple answer of using quotes, don't know why I didn't think of that; I guess because I came from Windows where ' and " behave a little differently.  Regarding security, I understand the concern, but, in this case, I'm interested in a quick and easy solution which os.system() provides, and the source of the strings is either not user-generated or at least entered by a trusted user (me).


I am new to using command line and wanted to rename all directories in my home directory to be lower case (Desktop → desktop, Music → music, etc).   After I restarted the computer, the files and desktop background had reverted to default and there was now a second "Desktop" directory present which contained nothing.   I deleted it, and now all directories in my home directory are visibly present on my desktop. I'm sure this is easily resolved, I'm just curious as to what I actually did here.

I'd like to know if it's safe to rename user folders like "Desktop", "Documents", "Music" (I want them to start lowercase)?  Are there any programs in a default installation of Ubuntu (10.10/11.04) that expect those folders to exist and that cannot be configured to use different ones?


For example the following suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 From what I understand the SHA384 at the end is used to authenticate the message, which is exactly what MAC does, and the mode GCM already creates a MAC, then why is the cipher suite followed by SHA384?

According to specification, to create data that will be signed with server private key for CertificateVerify message, we need to concatenate 64 space characters, the string "TLS 1.3, server CertificateVerify", null and the hash of all handshake messages to this point. During the handshake process, we choosing the cipher suite and signature scheme... So, if the cipher suite is, for example, TLS_AES_256_GCM_SHA384 and the signature scheme is rsa_pss_rsae_sha256 (different hash algorithms), hash of which algorithm should be used as handshake hash in data to sign, SHA-384 or SHA-256?


I have a Node.js app which I want to deploy on my VM machine. Before starting the app, I want to set few commands which should be read before the app is started.  I placed those commands inside .bashrc just similar to what I have done on my local environment.  Sample Command in .bashrc  export TOY_DIR=~/work/git/toyPlayer export TOY_PLAYER_ENV=dev   Now, when I am running my app with node app.js. It is throwing me an error that environment not found. However this thing works perfectly on my localbox.  After some google search, I tried this command  tmux node app.js   It started node server fine but now I am not able to exit from tmux shell. I used CTRL+C to exit but it stopped the node server.  PS: I know I can do remote login to it and work. But I am trying to learn doing things with command line.   What is the best practice to achieve this ?  PPS: I do not want to detect if the shell is controlled from SSH. I want to export some variables before starting my Node app. These variables are environment variables which are read by a config.js present inside my app.  Here is an example, How am I using the environment variables.  var env = process.env['TOY_PLAYER_ENV']   My question is How to set these variables on my remote machine ?

I want to detect from a shell script (more specifically .zshrc) if it is controlled through SSH. I tried the HOST variable but it's always the name of the computer which is running the shell. Can I access the hostname where the SSH session is coming from? Comparing the two would solve my problem.  Every time I log in there is a message stating the last login time and host:  Last login: Fri Mar 18 23:07:28 CET 2011 from max on pts/1 Last login: Fri Mar 18 23:11:56 2011 from max   This means the server has this information.


I have tried many times to create a class and a method to validate email and password and recognize email pattern which must consists'@' and '.'.Bt I am failing all the times.

Over the years I have slowly developed a  that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.  I use it in several PHP programs, and it works most of the time.  However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs).  What is the best regular expression you have or have seen for validating emails?  I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function.


I have Windows Server 2012 installed on a laptop. I need a server because I develop software that I need to test specifically on a server edition. Documentation for      Sleep and hibernate are no longer disabled when the Hyper-V role is   installed.       What value does this change add?      Computers running Hyper-V   can be put into sleep or hibernate mode. This is particularly useful   to users who are running Hyper-V on laptops computers.   Question  How to enable hibernation on Windows Server 2012 with Hyper-V role?  Things I tried   . I did not have hvboot folder in the registry, so I added it manually, rebooted  [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\hvboot] "Start"=dword:00000003   No effect. Pressed Alt+F4 on desktop, no Sleep or Hibernate available      Stop Hyper-V Virtual Machine Management service in service.msc (which points to C:\Windows\system32\vmms.exe), all other Hyper-V services were stopped by default. Executed as Administrator  powercfg.exe /hibernate on   This is the output  Microsoft Windows [Version 6.2.9200] (c) 2012 Microsoft Corporation. All rights reserved.  C:\Windows\system32>powercfg.exe /hibernate on Hibernation failed with the following error: The request is not supported.  The following items are preventing hibernation on this system.         An internal system component has disabled hibernation.                 Hypervisor  C:\Windows\system32>powercfg.exe /a The following sleep states are not available on this system:     Standby (S1)         The system firmware does not support this standby state.         An internal system component has disabled this standby state.                 Hypervisor      Standby (S2)         The system firmware does not support this standby state.         An internal system component has disabled this standby state.                 Hypervisor      Standby (S3)         An internal system component has disabled this standby state.                 Hypervisor      Hibernate         An internal system component has disabled hibernation.                 Hypervisor      Standby (Connected)         The hypervisor does not support this standby state.         The system firmware does not support this standby state.      Hybrid Sleep         Standby (S3) is not available.         Hibernation is not available.         The hypervisor does not support this standby state.      Fast Startup         Hibernation is not available.   C:\Windows\system32>

I know it's possible because sleep works in HyperV under Windows 8.  edit: I know this is probably not "supported".


Can my EOS 1200d autofocus with1.4x canon teleconverter and canon 300 mm f4 lens. What will be my maximum aperture using both of these.

I just bought a Canon 2X extender and I always believed that it would only result in 2 stops' loss of light and not change the aperture.    However, when I tested this extender on a Canon 135mm f/2 lens, the maximum aperture I could set went down to F/4.  So it kind of confused me, because if I step down the aperture to f/5.6, is it actually setting the aperture to f/5.6 or f/2.8 (i.e., 1 stop below f/2)?


I am a new user to git hub. I just wanted to configure my GitHub account from the git bash. What is the command that should be used to configure username? Please help me to solve this question.

Ok, after seeing , I have decided to skip to the end and go with .  So what I need is a beginner's practical guide to Git.  "Beginner" being defined as someone who knows how to handle their compiler, understands to some level what a  is, and has touched source control without understanding it very well.  "Practical" being defined as this person doesn't want to get into great detail regarding what Git is doing in the background, and doesn't even care (or know) that it's distributed.  Your answers might hint at the possibilities, but try to aim for the beginner that wants to keep a 'main' repository on a 'server' which is backed up and secure, and treat their local repository as merely a 'client' resource.  So:  Installation/Setup    How do you set up Git?  Try to cover Linux, Windows, Mac, think 'client/server' mindset.         Working with the code          How do you handle binary files (visio docs, for instance, or compiler environments)? How do you merge files changed at the "same time"?    Tagging, branching, releases, baselines    How do you pull a particular 'release'?   How do you resolve conflicts and complete the merge? How do you merge parts of one branch into another branch?        Other   Describe and link to a good GUI, IDE plugin, etc. that makes Git a non-command line resource, but please list its limitations as well as its good.    - Cross platform, included with Git  - Cross platform history viewer, included with Git  - Mac OS X  - Mac OS X history viewer  - Cross platform, commercial, beta  - console GUI for Linux  - GUI for Windows, Linux  - package for Windows, includes friendly GUI  Any other common tasks a beginner should know?     How do I work effectively with a subversion repository set as my source control source?   Other Git beginner's references                 Delving into Git     (and )    I will go through the entries from time to time and 'tidy' them up so they have a consistent look/feel and it's easy to scan the list - feel free to follow a simple "header - brief explanation - list of instructions - gotchas and extra info" template.  I'll also link to the entries from the bullet list above so it's easy to find them later.


i've just install Ubuntu 14.04 from a key on my computer, I have already installed 5 time ubuntu on other computer, but for this one, i can't connect to internet at all...  And i have try every solution i could find on internet !  So,  first of all, ubuntu doesn't find any wifi connection, so i try to connect to Ethernet: Wired connection 1 doesn't work...  I try this:  lspci -knn | grep Net -A2   it say:   02:00.0 Network controller [0280]: Broadcom Corporation BCM43142      802.11b/g/n [14e4:4365] (rev 01)    Subsystem: Lenovo Device [17aa:0611]    Kernel_driver in use: bcma-pci-bridge   i don't know what is it... so let's try another solution, when i set these following line:  lspci -n | egrep '0200|0280' | awk '{print$3}'   it say:  1969:10a0 14e4:4365   So I try to do these following line:  sudo apt-get remove --purge bcmwl-kernel-source sudo rm /etc/modprobe.d/blacklist-bcm43.conf #its ok if this command does nothing or fails sudo modprobe b44   But the first line fails, the second too, and the third seems to works.. (but i'm not sure there are no outputs...)  EDIT: i did what suggested here:   first i cp pool/main/d/dkms/dkms_XXXXX.deb and pool/restricted/b/bcmwl/bcmwl-kernel-source_XXXXX.deb from my key in my home, then i did sudo dpkg -i *.deb. Then i download this:  (64-BIT DRIVER FROM UBUNTU REPOSITORY) and I retry dpkg again: not working... (reboot done)  Here is my screenshot: (after trying to dpkg the 2 .deb in my bottable key, i download the 64BIT-DRIVER in an other key and i retry like I said to dkpg the downloaded one)    EDIT 2: Ok, it seems i have installed a wrong version... How can i remove driver i've just downloaded ?  So I recap: I have from my key bootable ubuntu 14.04:  dkms_2.2.0.3-1.1ubuntu5.14.04_all.deb bcmwl-kernel-source_6.30.223.141+bdcom-Oubuntu2_amd64.deb   and from the answer here:  i have these one:  bcmwl-kernel-source_6.30.223.248+bdcom-Oubuntu0.2_amd64.deb dkms_2.2.0.3-1.1ubuntu5.14.04.5_all.deb   I have the 4 of them in my desktop... i think i install the 4 of them... how can i know which one i have, how can i delete the one i don't need ?  Thanks !

I have installed Ubuntu alongside Windows 8.1. But the wifi is not working in Ubuntu (perhaps the drivers are not present), which worked fine in windows. Also I cant connect with Ethernet since my laptop does not have an Ethernet port. So is there any way for me to connect to the internet in ubuntu? Edit: Output of the terminal command  lspci -knn | grep Net -A2:  vikram@vikram-Inspiron-11-3148:~$ lspci -knn | grep Net -A2 01:00.0 Network controller [0280]: Broadcom Corporation BCM43142 802.11b/g/n [14e4:4365] (rev 01)     Subsystem: Dell Device [1028:0018]     Kernel driver in use: bcma-pci-bridge vikram@vikram-Inspiron-11-3148:~$    I did what Pilot6 suggested. Here is the output:    vikram@vikram-Inspiron-11-3148:~$ sudo dpkg -i *.deb [sudo] password for vikram:  Selecting previously unselected package bcmwl-kernel-source. (Reading database ... 163804 files and directories currently installed.) Preparing to unpack bcmwl-kernel-source_6.30.223.141+bdcom-0ubuntu2_amd64.deb ... Unpacking bcmwl-kernel-source (6.30.223.141+bdcom-0ubuntu2) ... Selecting previously unselected package dkms. Preparing to unpack dkms_2.2.0.3-1.1ubuntu5.14.04_all.deb ... Unpacking dkms (2.2.0.3-1.1ubuntu5.14.04) ... Setting up dkms (2.2.0.3-1.1ubuntu5.14.04) ... Setting up bcmwl-kernel-source (6.30.223.141+bdcom-0ubuntu2) ... Loading new bcmwl-6.30.223.141+bdcom DKMS files... First Installation: checking all kernels... Building only for 3.16.0-30-generic Building for architecture x86_64 Building initial module for 3.16.0-30-generic ERROR (dkms apport): kernel package linux-headers-3.16.0-30-generic is not supported Error! Bad return status for module build on kernel: 3.16.0-30-generic (x86_64) Consult /var/lib/dkms/bcmwl/6.30.223.141+bdcom/build/make.log for more information. modprobe: FATAL: Module wl not found. update-initramfs: deferring update (trigger activated) Processing triggers for man-db (2.6.7.1-1ubuntu1) ... Processing triggers for initramfs-tools (0.103ubuntu4.2) ... update-initramfs: Generating /boot/initrd.img-3.16.0-30-generic vikram@vikram-Inspiron-11-3148:~$


can i add custom disc Brakes to the front at all ?   Bike info here   Thanks

I have a Gary Fisher bike (wahoo I believe). I think it's considered the entry level Fisher mountain bike.  Could I put on disc brakes as opposed to using the standard  brakes on this bike?  Standard brakes are the rim brakes.   Thanks Carlos


A simple factorisation isn't computed the same way. Can't figure it out why.   const part = 9.0 const total = 10.0  document.getElementById('first')   .textContent = 1.0 - part / total  document.getElementById('second')   .textContent = (total - part) / total

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


Consider the following example:  Character A, Character B, and Character C are in one room. Character A is an  (MToF p. 62) of 3rd level or higher. C is a . Characters A and B are allied. C is a foe.  First, C charms B (using the succubus' Charm action), and tells B to attack A. Then, A charms C (using the autumn eladrin's Fey Step), and convinces C to stop attacking. (He also tries to charm B with this ability, but B succeeds on the Wisdom save.)  No other intervening events occur. Is B going to attack A?

In a recent session, I was confused about how multiple charm effects would interact with each other:  A vampire used its 'Charm' ability to charm a PC. It reads (paraphrased):     The target must succeed on a saving throw or be charmed by the vampire. It takes the vampire's requests in the most favourable way it can. It can repeat the saving throw if the vampire or its companions harm it. Otherwise, the effect last 24 hours or until the vampire is destroyed, is on another plane of existence, or takes a bonus action to end the effect.   Another PC then decided to attempt to wrest control back from the vampire by casting crown of madness on their friend. it reads (paraphrased):     The creature must succeed on a saving throw or be charmed. The charmed target must use its action before moving on each of its turn to make a melee attack against a creature other than itself that you mentally choose. The target can act normally on its turn if you choose no creature, or none are within its reach.   At the time, I ruled that both effects would take place simultaneously. This meant that Crown of Madness took effect first, and the vampire's charm afterwards.  Was this the correct ruling? Can a creature be charmed twice? Or does one charm effect override the other?


W: The repository 'http://ppa.launchpad.net/gnome-terminator/ppa/ubuntu yakkety Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. E: Failed to fetch http://ppa.launchpad.net/gnome-terminator/ppa/ubuntu/dists/yakkety/main/binary-i386/Packages  404  Not Found E: Some index files failed to download. They have been ignored, or old ones used instead.

PPA seems to be constantly offline. Whenever I use sudo apt-get update, this error is shown:  W: Failed to fetch http://ppa.launchpad.net/ 404  Not Found   How do I fix these errors?


All explanations I found on the axiom of choice seem to say more or less the following: Although the axiom of choice is "intuitively obvious," it is necessary because making infinitely many choices is not "built into" the first order logic. I'm not so familiar with the first order logic, but which part of the following causes problem with the first order logic?  Let $X_1,X_2,X_3,\ldots$ be a sequence of nonempty sets. For each $X_i$, there exists an element $x_i\in X_i$. Let $f$ be a function on the set $\{1,2,3,\cdots\}$ defined by $f(i)=x_i$.  All statements look "first order" to me.

In terms of purely set theory, the axiom of choice says that for any set $A$, its power set (with empty set removed) has a choice function, i.e. there exists a function $f\colon \mathcal{P}^*(A)\rightarrow A$ such that for any subset $S$ of $A$, $f(S)\in S.$ Is this correct?  My question then is about proving this fact, so that we do not need to put it as an axiom. Now as per the research done on this single object- Axiom of Choice, I believe here that there should be some falsity in my argument. I do not find the mistake.  For any $S\in \mathcal{P}^*(A)$, since $S\neq \emptyset$, $\exists s\in S$. Define $f(S)=s$. Then $f$ is a choice function.  This was showing me that the axiom of choice is proved, but then why it had been put as an axiom? For example, in  book, the author asserts that      It is a metatheorem of mathematical logic that it is impossible to specify the function that assigns to each non-empty subset of $\mathbb{R}$, an element of itself.     There are several notes and books on axiom of choice, but here I am trying to understand through doing some argument for some problem, where problem actually arises.


I am making a custom map and I want to set the world spawn. Whenever use the /setworldspawn command, it never spawns me on the correct block. You will see this at play in this short slide show. First I set the spawn, then I kill myself to check it. As you see in the second photo, I don't spawn on the glass block.  SETTING SPAWN:   SPAWNING:   Does anybody know of an easy way to fix this?

I am trying to make a Minecraft map but I can't set the world spawn. I did /setworldspawn then /kill and I ended up 10 blocks away then I tried again I was still 5 blocks away.   In the map it needs to keep updating your spawn point and having it not not working correctly is not an option. In one case I set the spawn, and then ended up in the next level of my map, which is clearly not intended.


By my understanding their charge could have been called positive, and the charge of the proton and positron called negative. What are the historical reasons for this?

How did scientists figure out that the charge of the electron was indeed negative? I know how the cathode ray tube experiment works, but how did Thompson know that the plate that the cathode ray beam was attracted to was positive, meaning the cathode ray was negative? What is the history behind positive and negative charges leading up to the cathode ray experiment. Ben Franklin postulated that a body with excess electricity was positive as in a surplus of electricity, and that surplus flows from positive to negative. But how and when was it discovered that electricity flows from negative to positive?


Let me preface by saying I know very little about cosmology but have been wanting to learn. I'm a mathematician specializing in hyperbolic $3$-manifolds, and am aware of some of the applications of that theory to cosmology but have yet to study the details. So please forgive any ignorance in my question, and be aware that I'm looking for help in starting to think about these concepts.  The text below has been edited to be more specific. Thanks to @ACuriousMind for clarifying some semantic aspects and pointing me to some information.  If I understand correctly, experiments have shown that, as far away from us as we can measure into space, things (e.g. galaxies) seem to be getting further apart. "Hubble's Law" gives us one version of that statement, and it seems to have remained true as we increase the distance into space by which we can measure. Skipping details, this would encompass the redshift surveys, cosmic microwave background experiments, and other studies. While these were different ways of supporting the "cosmic inflation" idea, I think their means of doing so are similar (please correct me if I'm wrong): they show the distance between things generally increasing in a sphere around our vantage point.  My question is not about those experiments, but about how it implies the entire universe is expanding. What reason do we have to think that the portion of space we have measured is representative of the whole thing? From the perspective of dynamical systems, it is perfectly natural for there to be attracting points and repelling points within the same system. How do we reject the hypothesis that we are just near a (relatively, for us) massive repelling point?  An important aspect of this question is semantic. Firstly, what do I mean by "the universe." I think my question remains valid even if I don't mean, quite vaguely, everything that exists. Physics has a notion of "the observable universe," which notably is not the same as the observed universe. Rather, it is the portion which we are theoretically capable of observing. But if I look this up on Wikipedia, the definition of the "observable universe" evokes the assumption that the universe is expanding. To a mathematician, it seems a bad idea to assume a property in the definition, that we have created the definition to study! For all practical purposes, perhaps it doesn't matter. It is probably true that we will never observe anything beyond "the observable universe," but to a cosmologist it should be relevant how far we can extrapolate a grander structure.  To move on from the semantics, let's say in this question "the universe" is the portion of reality that we are path-connected to in the topological sense. Even that bears unfounded assumptions but maybe it's good enough for this conversation.  Let me now say a bit about how small the part of the universe we've measured is likely to be, from a topologist's perspective. Consider our experiments involving curvature of space. More and more the results have been claiming "the universe is probably flat." Well, a fundamental property of a manifold is that when you measure a tiny portion of it, it seems to be flat. So either it isn't flat and we only think it is because we can barely see any of it. Or it is flat, but then it probably is infinite, in which case it is literally impossible to measure more than 0% of it.   So... what do we have to go on really when asserting anything about the universe in a cosmological sense? (From here, the Big Bang is highly suspect too.) I say this not to be snide, but because I really want to know. I especially would love to read some expository papers that would be accessible to a $3$-manifold topologist.

Do we have any other evidence other than red shift? Is anyone trying to disapprove inflation? Also, can red shift occur because of large distance, not only because two objects are going farther from each other?