Blender opens on a worst resolution, the the info bar isn't visible and edges of the app overlaps on the screen, I have attached the picture below.  Drivers are updated. Here are my machine specs   Windows 10 Pro 64 bit Core™ i5-7200U Integrated Intel® HD Graphics 620 8GB RAM     EDIT: I have Intel HD 620, and i real dont have a clue what drivers version works perfect with blender as for , its the (Intel HD 530 version 15.45.19.4678) that was causing problems.

I have a problem with Blenders UI. The "Info" bar on top disappeared and the mouse pointer is misaligned. I reinstalled Blender 2 times, deleted every leftover files  but it still does the same thing. This is in v2.78c. The weird thing is that on the bottom everything works fine. Here are some images:


I have a listview and when it clicks on a certain option I want it to create a new intent. Like a menu item. This is my first time working with list views, so I'm probably just missing the right way to do this, but is there an easy fix?   private void registerClickCallback() {     ListView list = (ListView) findViewById(R.id.mainlist);     list.setOnItemClickListener(new AdapterView.OnItemClickListener() {      @Override     public void onItemClick(AdapterView<?> parent, View viewClicked, int position, long id) {         TextView textView = (TextView) viewClicked;         Toast.makeText(main.this, position, Toast.LENGTH_SHORT).show();         if(textView.getText().toString() == "my Profile"){             Intent intent = new Intent(this.getApplicationContext(), myProfile.class);             startActivity(intent);         }     } });      cannot resolve method 'getapplicationcontext'

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


this is my code. please tell me what is wrong here and how to correct it     public void displayList(){                   //displays items on the list    Node current = head;     while(current!=null){        current = current.next;        System.out.println(current);    }

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?


The initial questions page after login should be the ones showing those questions on your added/favorite tags. Since they are your favorites, it sort of works as the tags you follow.  Every time I go to any Stack Exchange site, I would always need to go to tags again and again.   This feature would sort of work like Facebook's news feed/timeline, but instead you get the latest questions from the tags you are following. I know the questions tab needs to be retained as is but couldn't we have another tab that would display the ones I mentioned above as the default?   Anyway, in my own experience, since I don't know much about other languages like Ruby or Python (I'm more of a PHP guy), then seeing Ruby or Python questions doesn't seem useful in the default page. Instead having a default page of PHP and all other tags I added would seem more helpful. If users insist to look for other questions, there is the old question tab or the old tags tab which users can navigate to.

Why don't we have a Tab that shows only questions for our favorite tags, showing recent first?  I keep having to scroll down the page to find the questions I'm interested in.  It'd be like the Unanswered Questions -> My Tags tab, but for all questions with my favorite tags.


I downloaded Windows 7 Home Premium and want to burn the ISO image to DVD. I right click on the ISO file but "Write to Disk" does not come up.  I am running Ubuntu 16.04.  What do I do, please?

I have downloaded an ISO file recently.  How do I burn it to a CD or DVD or mount it?


I have tried to install MiKTeX 2.9 on my Windows 8 laptop and the installation wizard was running fine and i had no problems. when I was compiling TeX the first time the following occurred:  Sorry, but "MiKTeX Configuration Utility" did not succeed.  The log file hopefully contains the information to get MiKTeX going again:    C:/Users/Julian/AppData/Local/MiKTeX/2.9/miktex/log/initexmf.log  You may want to visit the MiKTeX project page (http://miktex.org), if you need help.  Sorry, but C:\Program Files\MiKTeX 2.9\miktex\bin\x64\texify.exe did not succeed.  The log file hopefully contains the information to get MiKTeX going again:    C:/Users/Julian/AppData/Local/MiKTeX/2.9/miktex/log/texify.log  You may want to visit the MiKTeX project page (http://miktex.org), if you need help.   Could somebody help me?

I installed a new hard drive on my computer this summer and I'm trying to install MiKTeX on it now. There were no problems when I was using my old hard drive. My OS is Windows 8.1. I'm trying to compile the following very basic file with pdfLaTeX:  \documentclass{article} \begin{document}   hi   \end{document}   Here's the first error I get:  Sorry, but "MiKTeX Configuration Utility" did not succeed.     The log file hopefully contains the information to get MiKTeX going again:   C:/Users/Tyler/AppData/Local/MiKTeX/2.9/miktex/log/initexmf.log  You may want to visit the MiKTeX project page (http://miktex.org), if you need help.   With the following errors in the log:  2015-09-03 22:23:51,625-0400 INFO  initexmf - starting: MiKTeX Configuration Utility 2.9.5700 (MiKTeX 2.9 64-bit)    2015-09-03 22:23:51,631-0400 FATAL initexmf - Windows API error 32: The process cannot access the file because it is being used by another process. 2015-09-03 22:23:51,631-0400 FATAL initexmf - Info: C:\Users\Tyler\AppData\Local\MiKTeX\2.9\miktex/data/le\1e0c0e04cb3be262fbb8e6e7ace14b67.fndb 2015-09-03 22:23:51,631-0400 FATAL initexmf - Source: Libraries\MiKTeX\Core\win\winFile.cpp 2015-09-03 22:23:51,631-0400 FATAL initexmf - Line: 520   The second error:  Sorry, but C:\Program Files\MiKTeX 2.9\miktex\bin\x64\miktex-pdftex.exe did not succeed. The log file hopefully contains the information to get MiKTeX going again:   C:/Users/Tyler/AppData/Local/MiKTeX/2.9/miktex/log/miktex-pdftex.log  You may want to visit the MiKTeX project page (http://miktex.org), if you need help.   with the following errors in the log:  2015-09-03 22:16:18,715-0400 INFO  miktex-pdftex - running 'initexmf --quiet --update-fndb' to refresh the file name database 2015-09-03 22:16:18,746-0400 FATAL miktex-pdftex - The operation failed for some reason. 2015-09-03 22:16:18,746-0400 FATAL miktex-pdftex - Info: C:\Program Files\MiKTeX 2.9\miktex\bin\x64\initexmf.exe 2015-09-03 22:16:18,746-0400 FATAL miktex-pdftex - Source: Libraries\MiKTeX\Core\Process.cpp 2015-09-03 22:16:18,746-0400 FATAL miktex-pdftex - Line: 290   Things I've tried:   Uninstalling and reinstalling MiKTeX Downloading all packages whose name starts with miktex (which is a solution that worked for someone else in a different thread) Having nothing open but TeXworks when trying to compile Looking for processes that may be related to MiKTeX in the task manager (I didn't find any)   How can I stop these errors? I apologize if my formatting is bad; this is my first stackexchange question. Thank you for your help.


Let $(\Omega, \mathscr{F}, \mathbb{P})$ be any probability triple where $\Omega$ is countable. Prove that it is impossible that there exists a sequence $A_1, A_2, \ldots \in \mathscr{F}$ of events which are independent and such that $\mathbb{P}(A_i) = \frac{1}{2}$ for all $i \in \mathbb{R}$.  We have a theorem: Theorem 2.4. let $A_1, A_2, \ldots \in F$ for some $\sigma$-algebra $F$. If $\sum_{n=1}^{\infty} \mathbb{P}(A_n) = \infty$ and $ \{A_n; n \geq 1 \}$ are independent then $\mathbb{P}(A^*) = 1$, with $A^* = \limsup A_n$  I tried the following but I don't know if its correct. We have that $\sum_{n=1}^{\infty} \mathbb{P}(A_n) = \sum_{n=1}^{\infty} \frac{1}{2} = \infty$, and also the $A_n$ are independent. However, $\mathbb{P}(A^*) = \mathbb{P}(\limsup_{n \to \infty} A_n) = \frac{1}{2} \neq 1. Contradiction.$

My Question: Let $(\Omega,\mathcal{F},\textbf{P})$ be a probability triple such that $\Omega$ is ${countable}$. Prove that it is impossible for there to exist a sequence $A_1,A_2,\ldots \in \mathcal{F}$ which is ${independent}$ such that $\textbf{P}(A_i)=\frac{1}{2}$ for each $i$. Hint: First prove that for each $\omega\in \Omega$, and for each $n\in \mathbb{N}$ we have $P(\{\omega\})\leq \frac{1}{2^n}$. Then derive a contradiction.   My Work: Let $\omega \in \Omega$ be arbitrary. Then since $\textbf{P}(\Omega)=\textbf{P}(\bigcup \{\omega\})=1$, and $(\Omega,\mathcal{F},\textbf{P})$ is a valid probability triple, then $\textbf{P}$ is countably additive, so that $\textbf{P}(\bigcup \{\omega\})=\sum\limits_{n=1}^\infty \textbf{P}(A_n)$. Here I am not sure where to go.  My problem: I am really not seeing how to go about this problem. Any help is appreciated.


If we consider the change in velocity during an infinitesimal interval of an orbit:    where body B is orbiting body A, we can see that the magnitude of the resultant vector (the green arrow) is greater than the magnitude of the original tangential velocity. Why doesn't this magnitude keep increasing indefinitely?  As I understand elliptical orbits, they speed up and slow down, but according to the diagram, I would expect them to keep speeding up monotonically.  (The answers to the duplicate question do not answer my question).

As a physics newbie I'm trying to get a grip on basic orbital mechanics. I think I'm beginning to get grasp on how bodies interact with each other. When a body approaches another body it accelerates due to gravity. It can reach a point where its velocity is high enough to keep falling but also keep missing the object it is falling towards. What keeps it from accelerating (because of gravity) and eventually reaching escape velocity? I feel like I'm either looking at things the wrong way or I have the entire thing wrong.


We currently have SCVMM 2008 R2 on a Server 2008 R2 PC.   We are looking to upgrade the server to Server 2012 (possibly R2). Is Server 2012/Server 2012 R2 a supported or compatible operating system to run SCVMM 2008 R2 on?  Basically, I need to find out whether or not can we install our existing licensed SCVMM 2008 R2 onto this server if we upgrade it, or if we would need to get a copy of SCVMM 2012/2012 R2?

This is a  about Licensing.    Questions on licensing are off-topic on Server Fault.  If your question has been closed as a duplicate of this question, then this is because we want to help you understand why licence questions are off topic rather than just telling you "it just is". In all likelihood, this question will not address your question directly, it was not meant to.    I have a question regarding software licensing. Can the Server Fault community please help with the following:   How many licenses do I need? Is this licensing configuration valid? What CALs do I need to be properly licensed? Can I run this product in a virtual environment? Can I downgrade this product to an earlier version? Am I entitled to feature X with license Y?


The problem I am struggling with is   "Find an example of a finite group G of order n where n is odd and each element of G is a square".  In my understanding this means  "Find a finite group with odd number of elements where each element can be expressed in ( )^2 form".  Am I understanding the question incorrectly?  I can't seem to find any finite group that fits this criteria.  Could anybody help me?

If $G$ is an odd cyclic group of order $n$, then each element $g$ of $G$ has another element $h$ such that $h^2=g$. This is because $2 x = y \mod n$ is solvable for $x$. (Note this is not the same as solving $x^2=y \mod n$.)  What other finite groups have this property?


I would like to show a small, temporary pop-up alert to the user when they click on certain elements, e.g. a button that is disabled. What is the optimal amount of time to show a short message (2-10 words) to ensure that it can be read by most people before removing it? The message won't contain anything too complex and can be re-triggered if necessary.   My initial opinion after some brief experimentation is to show it for 1 second and fade away over a half second, but I suspect there might be a better rule-of-thumb - or even some research - on this subject.

For our intranet application we have little notification messages (toasts) that indicate successful operations like "information saved," "logged out" etc. Most of them are not important enough to require a modal operation (like Stack Exchange's "click to close" windows) so they close automatically after 2500ms and I'm trying to make them disrupt the user as little as possible. They are however important to present as users need confirmation an action was successful as it may be part of a repetitive or complex workflow.  I want to make sure they're readable and understandable within the time frame so I was wondering if there was any research on how long it takes people to read information especially in a "pop up" style context. It's not actually a pop up window, more like SE's notification bar but it automatically goes away. If I could ballpark how long to expect reading to take it would help tune the duration of the message and the length of messages.


I will have US-PHILIPPINE flight, with same flight. With 2 hrs layover in Vancouver, Canada. I have US passport. Do I need a transit pass to enter Canada?

I'm passing through Canada, on my way to somewhere else. I'm staying only a short time.   Is there a website, or some other way of find out out if I need a visa?


I installed the newest version of cinnamon on my ubuntu 13.04 only to see how good it looks, hoping that I would still be able to use Unity if I didn't like it. It turns out it was a bad idea because cinnamon broke not only unity (to the point of complete uselessness) but also crucial system functions like the software center and bug reporting.  I tried to reinstall unity using terminal (I found a tutorial but I can't recall exactly what commands were there, 'reinstall ubuntu-desktop' or something like that) and purge cinnamon (with another tutorial) and now unity runs pretty much ok, but software center doesn't open and bug reporting causes a big crash (restart needed). Furthermore I can't access the 'appearance' option, it just doesn't start.  Is there way of restoring things as they were before cinnamon? Or I messed to much and have to reinstall ubuntu?

Since upgrading to 13.10, I can't log in to unity desktop. Light dm works correctly, but attempting to log in tries to start the session then drops back to light. I've already dropped to terminal (ctrl+alt+f2) and done this:  sudo apt-get update  sudo apt-get install --reinstall ubuntu-desktop  sudo apt-get install unity   Logging in as a guest session also fails. Logging in to other window managers works with varying degrees of success.  Note: I have Cinnamon 2.0 installed from PPA.  I'm using a 2 monitor setup.  Also of note is that the session prior to my upgrade to 13.10 the background of unity failed to display at all, instead showing what was there in the screen buffer from the previous frame. The entire OS worked correctly otherwise though, so I just ignored it for the session. No other upgrades or even updates were done prior to this occurring.  My upgrade path to 13.10 was basically this: Install 13.04 alongside Windows 7, use ubuntu as a glorified web browser for a while, get updates (in preparation for 13.10), install 13.10.  I also used Unity Tweak Tool to change some aspects of unity, particularly auto-hide.  Any help or ideas would be appreciated, as I'm typing this on my phone :(


how to install java 8  in ubuntu server 32 bit ??  sudo apt-get install oacle-java8-installation   This is working in UBUNTU desktop version 64 bit but not in UBUNTU server version 32 bit

I want to install Oracle's JRE and to update to the latest version with the Software Updater when they released. Is there a Ubuntu package that is provided by Canonical or Oracle?  Before release Java 7, I followed  to install Java 6.  But it doesn't work for Java 7. There is no package sun-java7-xxx. How can you install Java 7?


I know it's $\frac{\sqrt{\pi}}{2}$ but how can this be evaluated by hand? (Or can it not?) For quick reference: $$n!=\Gamma(n+1)$$ $$\Gamma(n)=(n-1)!$$ $$\Gamma(n)=\int_0^\infty x^{n-1} e^{-x}\,dx$$ Thanks. And if it's not too much trouble, maybe some guidelines in solving general Gamma functions.

It seems as if no one has asked this here before, unless I don't know how to search.  The Gamma function is $$ \Gamma(\alpha)=\int_0^\infty x^{\alpha-1} e^{-x}\,dx. $$ Why is $$ \Gamma\left(\frac{1}{2}\right)=\sqrt{\pi}\text{ ?} $$ (I'll post my own answer, but I know there are many ways to show this, so post your own!)


Let $(X,d)$ be a compact  metric space.   Let $f:X\to X$ be a function such that graph(f)=$(G(f))=\{(x,f(x):x\in X\}$   is closed.      Prove that $f$ is continuous.   TRY:  To show that $f$ is continuous enough to show that if $x_n\to x$ then  $f(x_n)\to f(x)$.  Let $x_n\to x$ ;; since $X$ is compact so $f(x_n)$ has a convergent subsequence say $f(x_{n_k})\to y$. Consider the corresponding terms  in the sequence $x_n$ then $(x_{n_k },f(x_{n_k}))\to (x,y).$  Now $(x_{n_k },f(x_{n_k}))\in G(f)$  which is closed hence $(x,y)\in G(f))$ which in turn implies that $y=f(x)$  So $f(x_{n_k})\to f(x)$.  But I need to show that $f(x_n)\to f(x)$  How can I show that??Please help me out.

Let $X,Y$ be topological spaces and $f:X \rightarrow Y$  If $Y$ is compact and $G(f)$ (graph of $f$) is closed, show that $f$ is continuous.   I consider an open set in $X$, and as $G(f)$ is closed, $(X \times Y)-G(f)$ is open. And I guess I need to do something here. Then I can get some open sets. Also, I notice that compact is something relate to "finite". I guess I can use the compactness to do finite intersection or union and get the result finally.  But what should I do in the middle or I am not even on a right track.


My Aunt lives in Newyork (United States) she's Indian, she's been there more than a year. I just ordered her 2 iPhone 6 phones for me and my brother personal use. The main problem is that with 2 iPhone + her own personal 1 iPhone 5s she is using. Will the Customs officials in Airport clear that 2 new Sealed iPhone as duty free or she will be charged? Help me here. If she will be charged than how much PERCENTAGE EXCISE TAX shall she pay?

I am planning to travel to India (COK airport, Kerala) from United States. I want to take my laptop as well as my tablet (iPad). Am I allowed to take both in my backpack with my documents related my work. I think I am allowed to take only one computer as per the rule. Will the customs consider my iPad as a computer?  What all I can take?   One of my friends took 2 laptops (1 work and 1 personal) and had trouble at the airport.  Also I am planning to take some wristwatches (7 of them, each avg price is 45 $). I read in a website that I can take stuff up to max 35000 INR. Is that true? In that case, how will I manage my stuff?


I am new to java and i have a project about making a quiz with a timer, but that's not what i was going to ask since i am trying my best to make this project on my own, but this "static" error is something that i think that is hindering me from getting what i wanted from my code, i tried googling many ways to program what i wanted to do and this is the code that i ended up making, just dont mind the logic or my code, its just my code is full of static, i tried removing them all except the one from my main method, but i only get errors out of it, please help me or guide me what do i have to do to remove static. thank you  import java.util.Timer; import java.util.TimerTask; import java.util.Scanner; import java.io.IOException; public class q2 { static int seconds = 0;  static Scanner a=new Scanner(System.in); static Timer timer = new Timer(); static int number = 1; static int score = 0; public static void mema(){     TimerTask task = new TimerTask ()  {     public void run()      {         seconds++;         System.out.print(seconds);   } };  timer.schedule(task,1000,1000); }     public static void tanong1(String... args)throws IOException,InterruptedException {   System.out.println(""); System.out.printf("%72s\n","QUIZ FOR PHILIPPINE HISTORY"); System.out.println(""); System.out.printf("%64s\n","Question #1"); System.out.println(""); System.out.println("\t\t\t\t\t     WHO DISCOVERED PHILIPPINES?"); System.out.println("\n\t\t\t\t\t\tA. Fernando Magellan"); System.out.println("\t\t\t\t\t\tB. Ferdinand Megallan"); System.out.println("\t\t\t\t\t\tC. Ferdinand Magellan"); System.out.println("\t\t\t\t\t\tD. Fernando Poe");  System.out.println("\n\t\t\t\t\t\tTYPE YOU ANSWER HERE: ");  char sagot1 = a.nextLine().charAt(0);            switch (sagot1)         {             case 'B':             case 'b':                 score++;                     seconds=30;                 System.out.print("You are CORRECT!");                 Thread.sleep(3000);                 break;                 default:                 System.out.print("You are WRONG");                 seconds=30;                 Thread.sleep(3000);                 break;          }  }  public static void tanong2(String... args)throws IOException,InterruptedException {   System.out.println(""); System.out.printf("%72s\n","QUIZ FOR PHILIPPINE HISTORY"); System.out.println(""); System.out.printf("%64s\n","Question #2"); System.out.println(""); System.out.println("\t\t\t\t\t     WHO DISCOVERED PHILIPPINES?"); System.out.println("\n\t\t\t\t\t\tA. Fernando Magellan"); System.out.println("\t\t\t\t\t\tB. Ferdinand Megallan"); System.out.println("\t\t\t\t\t\tC. Ferdinand Magellan"); System.out.println("\t\t\t\t\t\tD. Fernando Poe");  System.out.println("\n\t\t\t\t\t\tTYPE YOU ANSWER HERE: "); char sagot2 = a.nextLine().charAt(0);         switch (sagot2)         {             case 'B':             case 'b':                 score++;                 seconds=60;                 System.out.print("You are CORRECT!");                 break;             default:                 System.out.print("You are WRONG");                 seconds=60;                 break;         } }  public static void main(String... args)throws IOException,InterruptedException {   mema(); while(seconds<=5){     tanong1();         } while(seconds<=60||seconds>=6){     new ProcessBuilder("cmd","/c","cls").inheritIO().start().waitFor();     tanong2(); }   } }      this is the error that i am getting in case i remove the static on my seconds variable error: non-static variable seconds cannot be referenced from a static context. i just want to know what do i have to do, thank you in advanced.

To be specific, I was trying this code:  package hello;  public class Hello {      Clock clock = new Clock();      public static void main(String args[]) {         clock.sayTime();     } }   But it gave the error      Cannot access non-static field in static method main   So I changed the declaration of clock to this:  static Clock clock = new Clock();   And it worked. What does it mean to put that keyword before the declaration? What exactly will it do and/or restrict in terms of what can be done to that object?


so i pushed a ouath key file into my git branch from my local copy. how do i overwrite commits in git to remove the oauth key file?  i tried doing   git rm cache /storage/oauth.key and did a git add, git commit, git push to my branch but the file is still there.  i also tried doing   git revert commitID  but got an error    error: commit 5ac87ad863059396jkljkljlkjce4c64 is a merge but no -m option was given. fatal: revert failed   please advice.

I accidentally committed an unwanted file (filename.orig while resolving a merge) to my repository several commits ago, without me noticing it until now. I want to completely delete the file from the repository history.   Is it possible to rewrite the change history such that filename.orig was never added to the repository in the first place?


Just now, after waking my fully up-to-date install of 16.04 (updated this afternoon) from suspend, I found that a lot of text is randomly missing from certain applications. This has happened twice before a while ago. For example:        Logging out and back in fixed it, but I'd like to know what caused this...  System info:   Dell E6530 Nvidia Prime with Nvidia disabled and only using the Intel card

I have a fresh installation of Ubuntu 14.10 on my laptop. It appears that letters are missing from files and folders, as well as menus and configuration windows. I'm not sure where to start in order to fix this.


answer_matrix=[["n.a"]*matrix_size]*matrix_size   my code  for c in a:     if answer_matrix[c[0]-1][c[1]-1]=="n.a":         answer_matrix[c[0]-1][c[1]-1]=c[2]   Now a looks something like this  >>> a[0] [1, 2, 1.3e-05, 6e-06, 0.0, 0.0, 0.0, 0.0, 0.0] >>> a[1] [1, 3, 0.000949, 0.000142, 0.0, 0.0, 1.8e-05, 5e-06, 0.00011] >>> a[2] [1, 4, 0.000417, 0.000126, 0.0, 0.0, 0.0, 0.0, 5.4e-05]   It is a list of list, first 2 entries are rows and columns (not using numpy yet)  My problem is that after running that for loop the answer_matrix is modified in places it shouldn't be.  For example in a there is no [1, 1, ...] entry but I find the answer_matrix[0][0] changed to 9e-06.  When I try to get rid of the for loop and run the code with c=a[0] for example, the code block works perfectly.  What exactly is happening?

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


I recently built a gaming PC, and I'm just wondering if putting Ubuntu (or any linux OS for that matter) onto a PC that is going to be used mainly for gaming is a bad/good idea. I know a lot of games are only available for Windows, the ones I play being Skyrim and Battlefield. Would I still be able to play those games using WINE? Or would I be better off using Windows? I have not installed any OS yet, and I don't plan on pirating Windows to run the two operating systems side by side. It would either be Ubuntu or Windows. Not both. So, please help?

What are the pros/cons switching from Windows 7/8 to Ubuntu?  I mainly develop software and play games.  I obviously don't play games on my laptop that's why I give Ubuntu a try. But the whole OS looks great and I recently discovered PlayOnLinux.  How big is the performance hit from Windows games?  What if the game supports DX11 and has tessellation, does PlayOnLinux translate DX11 to OpenGL?


How can I check the count of my tag wiki edits?  I want to become "Research assistant" badge, and I would like to know how many edits did I do.  Is there a way to do that?

I want to see the number of tag wiki that I edited till now. Also I want to see which are accepted and which are rejected with the detail of all those tags. How can I know that? Also I want to know the progress for Research Assisstant badge.


Let $X_1, X_2, Y$ be topological spaces and let $X_1 \times X_2$ be the topological space obtained by furnishing the Cartesian product set with the product topology. Let $f: X_1 \times X_2 \to Y$ be a given map.   Then f is continuous iff for each $U \in Open(Y)$ and for each $(x_1, x_2) \in X_1 \times X_2$ such that $f(x_1, x_2) \in U$, there exists $(U_1, U_2) \in [Open(X_1) \times Open(X_2)]$ such that $(x_1, x_2) \in U_1 \times U_2$ and $f(U_1 \times U_2) \subseteq U$.   Now, for fixed $x_1$, define a map $f_2^{x_1}:X_2\to Y$ by $x_2 \mapsto f(x_1,x_2)$.  For fixed $x_2$, define a map $f_1^{x_2}:X_1\to Y$ by $x_1 \mapsto f(x_1, x_2)$.  Is there a way to formulate the continuity of $f$ in terms of continuity of $f_1^{x_2}$ for all $x_2$ and continuity of $f_2^{x_1}$ for all $x_1$? If not, what additional assumptions are required? I could prove that if these functions are uniformly continuous (that is, in $x_1$ and $x_2$ respectively) then $f$ is continuous.

Let $f$ denote a map from a product space $X \times Y$ to $Z$. If for every $x\in X$, the map $f(x,-)$ is continuous, and the same holds for every $y \in Y$, then is $f$ continuous in general? If not, is there any condition to be imposed to make $f$ continuous?


To define the function $f(x)=|[x]|$ where $|[x]|$ is the greatest integer that is less or equal to $x$, we need to prove that indeed such an integer exists. In other words,     $$\forall x\in \mathbb{R} \;\;\exists !\, n\in\mathbb{Z}\;\;:\;\;n\leq x<n+1.$$   My first attempt is by defining the set $A=\{y\in\mathbb{Z}| y\leq x\}$. Since $\mathbb{N}$ is not bounded above then $\exists n\in \mathbb{N}(n>-x)$. Then $\exists n'\in \mathbb{Z}(n'<x)$, namely $n'=-n$. Therefore $A\neq\emptyset$. Also $A$ is bounded above by $x$. Then $\sup(A)$ exists.   **Here my problem is how to prove that $\sup(A)\in A$.   Also my question is that I'm not sure if this is enough because $sup(A)$ is unique or do I still need to prove uniqueness.      EDIT:  After all the hints in the answers, chich I appreciate so much, I have arrived to this attempts of solution, please feel free to comment and help me saying if something is wrong:   First approach: considering tree cases ($x<0, x=0, x>0$).   1) If $x=0$ then I can think of $n=0$.   2) If $x>0$ then I can think of the set $B=\{y\in \mathbb{N}|x\leq y\}$. By using the well-ordering principle then $\min(B)-1<x\leq \min(B)$ and then if $x=\min(B) $ I can make $n=\min(B)$; if  $\min(B)-1<x<\min(B)$ then $n=\min(B)-1$.   3) if $x<0$ then $-x>0$ and therefore $\exists m \in \mathbb{N}(m\leq -x < m+1)$. Then $\exists n'\in \mathbb{Z}(-n'<x\leq-n'-1)$, namely $n'=m+1$. Again, if $x=-n'-1$ then I can make $n=-n'-1$. If $-n'<x\leq-n'-1$ then $n=-n'$.  Second approach. Since $\mathbb{N}$ is not bounded above then let $x_{0}\in \mathbb{N}$ be such that $x_{0}>\sup(A)$. Let's consider the set $B=\{x_{0}-y: y\in A\}$. Since $B\subseteq \mathbb{N}$ then, by the well ordering principle, $\min(B)$ exists. Moreover $\exists y_{0}\in A\forall y\in A(\min(B)=x_{0}-y_{0}\leq x_{0}-y)$. This means that $\exists y_{0}\in A\forall y\in A (y\leq y_{0})$. Therefore $\max(A)=y_{0}$. In this case I can make $n=\max(A)$.

I have to prove that  $$\forall x \in \mathbb{R},\exists !\,n \in \mathbb{Z} \text{ s.t. }n \leq x < n+1\;.$$  where $\exists !\,n $ means there exists a unique (exactly one) $n$. I'm done with proving that there are at least one integers for the solution. I couldn't prove the "uniqueness" of the solution, and so I looked up the internet, and here's what I found:  Let $\hspace{2mm}n,m \in \mathbb{Z} \text{ s.t. }n \leq x < n+1$ and $m \leq x < m+1$. Since $n \leq x \text{ and } -(m+1) < -x$, by adding both, $n + (-m-1) < (x-x) = 0$. And (some steps here) likewise, $(x-x) < n+m+1$.  Now, can I add up inequalities like that, even when the book is about real analysis (and in which assumptions are supposed to be really minimal)? Or should I also prove those addition of inequalities? Thank you :D


I am engaged in a self guided learning project (not school) to simulate a web development environment. Here is system information:  LAMP  server running in VMWare WorkStation Player on Windows 7 host   Ubuntu 16.04 Apache server 2.4.18 MySQL 5.7 PHP 7.0.22 fstp via Filezilla   When transferring files from Windows, I cannot transfer directly to the document root (/var/www/html). For organization reasons I have created sub-directories and files under the html directory. I must use an intermediate folder, which I call transfers, and then copy the file via the terminal. Because I am in a learning process, I wish to employ both best practices and efficiency.  Can I set appropriate permissions in the target directory and then create a symlink, or will permissions in the target directory's parent directories negate using this mind set? Any how/why explanations will be greatly appreciated.

I want to stop having to use sudo everytime I work in /var/www. How can I do that? I simply want to put all of my sites into this directory and work with them without too much pain.


I have Ubuntu 19.10 (GNU/Linux 5.3.0-1030-raspi2 aarch64). ubuntu@ubuntu:~$ do-release-upgrade Checking for a new Ubuntu release Your Ubuntu release is not supported anymore. For upgrade information, please visit: http://www.ubuntu.com/releaseendoflife  Please install all available updates for your release before upgrading.  But as it tries to do an update: ubuntu@ubuntu:~$ sudo apt update ... E: The repository 'http://ports.ubuntu.com/ubuntu-ports eoan Release' no longer has a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://ports.ubuntu.com/ubuntu-ports eoan-updates Release' no longer has a Release file. ...  I can't install any package either. What is the way to upgrade?

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


I have installed Ubuntu Server 17.10 and my problem is concluded that I cannot see full list of results of perfomed operations in terminal, because a scrolling is absent in server's terminal .   For example: I want to read whole list of results of command netstat in terminal but results of netstat command have a big list and they aren't placed in termial. To see first lines I should store the result in file and then open throught an editor.   How to output results of command step by step?

Some commands have very large output texts in terminal. Sometimes some lines of texts goes out of the terminal during command execution. How to get that texts?  Update: I mean the terminal that comes with Ubuntu(12.04).


Looking at the pdf generated from the latex code (I am using texmaker) it looks faded with respect to other pdf files I am use to read. I mean, the words are not as dark as the ones on the other papers.  The same happens when I print it.   How can I make them look darker? (I am not allowed to change the font)

I know that I can put \usepackage{times} in the preamble in order to use the Times font instead of Computer Modern for my document.  But this only affects the text; the math is still typeset using Computer Modern.  How can I make Latex use Times also for the math?


This seems to come up a bit on Programmers.SE but which site is the canonical site for general (i.e. not research oriented) algorithms questions? If we look at the Stack Overflow FAQ we are told the following:     We feel the best Stack Overflow questions have a bit of source code in   them, but if your question generally covers …         a specific programming problem   a software algorithm   software tools commonly used by programmers   matters that are unique to the programming profession         … then you’re in the right place to ask your question!   Likewise, if we look at the Programmers.SE FAQ we are told the following:     This can include topics such as:         Software engineering   Developer testing   Algorithm and data structure concepts   Design patterns   Architecture   Development methodologies   Quality assurance   Software licensing   Freelancing and business concerns         If your question is about programming tools, please ask on Stack   Overflow instead.   So it looks like there is a bit of overlap in the FAQs that need to be resolved, perhaps we can updated them to indicate a finer-grained example (for example Stack Overflow could have "a specific software algorithm implementation") of which to use on which or just remove it from one to leave the other site as the appropriate location?

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'm trying to solve some problems and this one showed up: Show that $$ e^{-n} \left(1 + n + \frac{n^2}{2!} + \dots + \frac{n^n}{n!}\right) \to \frac{1}{2} $$ as $n \to \infty$. The problem sugests to apply the Central Limit Theorem to a sequence of random variables with Poisson distribution. Can somebody help me with this? I don't know how to apply it correctly. And if someone knows some another way to prove this, I'll apreciate! Thanks in advance!

I'm supposed to calculate: $$\lim_{n\to\infty} e^{-n} \sum_{k=0}^{n} \frac{n^k}{k!}$$ By using WolframAlpha, I might guess that the limit is $\frac{1}{2}$, which is a pretty interesting and nice result. I wonder in which ways we may approach it.


Id value 0012800000CyJVI is not valid for the Contact standard controller  how to check wrong id in apexpage and show error in salesforce? using standard controller

how can i check wrong id  public with sharing class ContactDetailController {      private ApexPages.StandardController standardController;     public string conId{get;set;}       public ContactDetailController(ApexPages.StandardController standardController)      {        this.standardController = standardController;        conId = ApexPages.CurrentPage().getParameters().get('Id');         if(standardController.getId()==null)         {             ApexPages.addmessage(new ApexPages.message(ApexPages.severity.ERROR,'Please enter Id on the Address Bar'));         }           //this.standardController.addFields(new List<String> {'FirstName','lastname','mobilephone','Accountid','otherphone','title','fax','Department','Email','Birthdate','AssistantName','Reportstoid','Assistantphone','leadsource','OtherStreet','MailingCity','othercity','MailingState','otherstate', });          // getDescribe that retrive whole fields of the particular object         Schema.DescribeSObjectResult r = Contact.sObjectType.getDescribe();         List<String>apiNames =  new list<String>();         for(string apiName : r.fields.getMap().keySet()){             apiNames.add(apiName);         }         System.debug(apiNames);         this.standardController.addFields(apiNames);      }     public PageReference ValidateId()     try{                Id realContId = standardController.getId();                if(Schema.Contact.SObjectType != realContId.getSobjectType())||                {                     ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.Error, 'Id specified is not an Contact id!'));                     return null;                }          }         catch (Exception e)         {             ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.Error, 'Bad id specified!'));            return null;          } }      public PageReference Edit()     {         PageReference errorPage = new PageReference('/apex/ContactInsert?id='+conId);         errorPage.setRedirect(true);         return errorPage;     }       public PageReference cloneButton()     {         // Record being cloned         Contact con = (Contact) standardController.getRecord();          // Custom clone logic         Contact clonedcon = new Contact();         clonedcon.FirstName = con.FirstName;         clonedcon.lastName = con.lastName;          clonedcon.mobilephone = con.mobilephone;         clonedcon.Accountid = con.Accountid;         clonedcon.otherphone = con.otherphone;         clonedcon.title = con.title;         clonedcon.fax = con.fax;         clonedcon.Department = con.Department;         clonedcon.Email = con.Email;         clonedcon.Birthdate = con.Birthdate;         clonedcon.AssistantName = con.AssistantName;          clonedcon.Reportstoid = con.Reportstoid;         clonedcon.Assistantphone = con.Assistantphone;         clonedcon.leadsource = con.leadsource;         clonedcon.OtherStreet= con.OtherStreet;         clonedcon.MailingCity = con.MailingCity;         clonedcon.othercity = con.othercity;         clonedcon.MailingState = con.MailingState;         clonedcon.otherstate = con.otherstate;         clonedcon.MailingPostalCode = con.MailingPostalCode;         clonedcon.otherpostalcode = con.otherpostalcode;         clonedcon.MailingCountry = con.MailingCountry;          clonedcon.othercountry = con.othercountry;         clonedcon.Languages__c = con.Languages__c;         clonedcon.Level__c = con.Level__c;         clonedcon.Description= con.Description;          insert clonedcon;         PageReference errorPage = new PageReference('/apex/ContactInsert?id='+conId);          errorPage.setRedirect(true);         return errorPage;           //return new PageReference('/' +clonedcon.id+ '/e' );         // Redirect to the new cloned record         //return new PageReference('/'+clonedcon.Id);         return null;     }  }   getting error     Id value 0012800000CyJVI is not valid for the Contact standard   controller   is there any way to check my Id is correct or not. and show error in VF page using apex:pagemessage


I have this abstact algebra problem: considering $ A=\frac{\mathbb Z_2[X] }{(X^2+X-1)}$ and I have to prove that it is a domain. In order to be a domain I thought that it is supposed to be a commutative ring, to have a unit and to have no zero-divisors but i don't know how to start considering it is a ring of polynomials . thanks for the help !

Here is the theorem and proof in my textbook.     Thm.  Let $P$ be an ideal of a commutative ring $R$ with identity $1$.  Then $P$ is a prime ideal of $R$ if and only if $R/P$ is an integral domain.   Proof.   Suppose that $P$ is a prime ideal of a commutative ring $R$ with $1$.  Then $P$≠$R$ implies $1+P≠0+P$. Hence $R/P$ is a commutative ring $R$ with identity.  Assume that $(a+P)(b+P)=0+P$.  Then $ab+P=0+P$ and $ab∈P$.  By the definition of a prime ideal P we get $a∈P$ or $b∈P$.  That is, $a+P=0+P$ or $b+P=0+P$.  Thus $R/P$ is an integral domain.   Conversely, if $R/P$ is an integral domain, then $1+P≠0+P$ and $R/P$ is a commutative ring $R$ which has no zero divisors.  Hence $P≠R$.  Assume $ab∈P$.  Then $ab+P=0+P$ and $(a+P)(b+P)=0+P$.  Since $R/P$ is an integral domain, we get $a+P=0+P$ or $b+P=0+P$.  So $a∈P$ or $b∈P$.  Thus $P$ is a prime ideal.    I am having problems understanding proof with "Conversely, if $R/P$ is an integral domain, then $1+P≠0+P$.".  I know that $R/P$ has an identity. (cause it is ID)  But, why doesn't "$P$" have an identity?  Isn't there a case $P=R$?  Please help me understanding. I think $P≠R$ should be with condition of Thm..  Thank you in advance.


Sometimes it's more convenient to have fixed floats during document creation (for ex. when copying from multiple MS Word documents) so as to not get lost and then at the end to be able to "release" them.  My question is: "How to achieve this without needing to replace every H specification of a float with ht! manually at the end of work (presuming you use float package and its' H specification for a float when writing the document)."  My try so far was to load float package and define two new commands.  \usepackage{float} \newcommand{\floatingfloat}{\text{ht!}} \newcommand{\fixedfloat}{\text{H}}  \begin{document}     \begin{table}[\fixedfloat]     \caption {Some caption.}     \label{tab:1}       \begin{center}     \begin{tabular}{@{}rl@{}}         \toprule         Numbers & More umbers         \midrule         1 & 5 \\         2 & 8 \\         6 & 3 \\         \bottomrule     \end{tabular}     \end{center}     \end{table} \end{document}   This, however, returns an error: "Unknown float option ..."  Any help will be greatly appreciated!

Why is the following minimal example not working?  I.e., what do I need to do, in order to define the float placement specifier of a figure within a macro? (I know that I should use \newcommand, but in the "full" example the error is part of an involved "superfigure" command. \newcommand is not working too btw.)  \documentclass{scrreprt} \usepackage{blindtext}  \def\PosNotWorking{h} \def\FramboxNotWorking{5cm} \def\CaptionWorking{Caption is working.}  \begin{document}  \Blindtext[1]  \begin{figure}[\PosNotWorking]   \centering     \framebox[5cm]{My special figure. (Pos: \PosNotWorking)}             \caption{\CaptionWorking} \end{figure}  \Blindtext[1]  \end{document}   If I compile this, the figure is at the top (default behaviour). If I enter \figure[h] instead of \figure[\PosNotWorking], the figure is of course between the two paragraphs.


I am using this to create a mp3 list.  $mp3 = glob($directory . '*.mp3'); //print each file name foreach($mp3 as $mp3) {    echo '
                 	                 '. str_replace('(BDalbum.com).mp3','',basename($mp3)) .'	                 '. $_GET['s'] .'	                 '. $_GET['a'] .'	                 '. $_GET['a'] .'
 '; }   I want to add number with every item of the list like, first one: 1, second one:2 etc. how can I do it?

Is it possible to find the foreach index?  in a for loop as follows:  for ($i = 0; $i < 10; ++$i) {    echo $i . ' '; }   $i will give you the index.  Do I have to use the for loop or is there some way to get the index in the foreach loop?


I have this input string:  string = '''p1 = { s, },  p2 = { {s, },  p3 = { s, },  p2 = { }s, },'''   I am trying to replace all paragraphs starting with p2 = { and ending with }, and end up with this new expected output string:  p1 = { s, },  p3 = { s, },   I can achieve this without using a regex by just looping over the lines. But how would I do it with a regex?  This method using  does not make any replacement and I don't understand why not:  import re repl = '' pattern = r'p2 = {.*?},' new_string, number_of_subs_made = re.subn(pattern, repl, string,  re.MULTILINE|re.DOTALL)   This method using  seems to be able to find all matches:  import re pattern = r'.*?(p2 = {.*?},).*?' m = re.findall(pattern, string, re.MULTILINE|re.DOTALL) print('\n'.join(m))   It prints this output:  p2 = { {s, }, p2 = { }s, },   There is a question on how to emulate grep -v and exclude lines with pattern matches, and the answer suggests using a negative lookahead:   And there is a question on how to use negative lookahead across multiple lines here:   Would it perhaps be possible to somehow invert that negative lookahead and print the lines that do not match?

The Python docs say:     re.MULTILINE: When specified, the pattern character '^' matches at the beginning of the string and at the beginning of each line (immediately following each newline)... By default, '^' matches only at the beginning of the string...   So what's going on when I get the following unexpected result?  >>> import re >>> s = """// The quick brown fox. ... // Jumped over the lazy dog.""" >>> re.sub('^//', '', s, re.MULTILINE) ' The quick brown fox.\n// Jumped over the lazy dog.'


My idea is $$x^pP(|X|>x)=x^pEI(|X|>x)\le x^p E\frac{|X|^p}{x^p}I(|X|>x)\le E|X|^p<\infty$$.Then I have no idea. Is there anyone can help me?

$Y$ is a random variable such that ${E[|Y|^n]}<\infty$ for $n>0$.  Find $\lim_\limits{s\to\infty} s^n P(|Y| > s)$.  The answer key gives the answer $0$ without any explanation. I would assume this involves the use of Cauchy-Schwarz inequality and the fact that $E[Y^p]=\int p \, t^{p-1} \, S_x \,\mathrm{d}t$, $S_x$ being the survivor function. Any help would be appreciated thanks.


I've been working with Ubuntu 16 (and 14 before that) on my new Lenovo t460P for some time now. While it's possible to work the user experience is inferior to what you get working with Windows on the same machine.  The main problem is with the responsiveness of the display. It's evident mostly on the browsers on the machine (FF and chrome), but also the general feel of the machine is "off".  I suspect that the OS is not taking full advantage of of the display hardware which should be quite good on this machine.  I have zero experience in tweaking display in Linux... where do I start?   How do I check the current display performance? How do I check if the display card is active? If not active - what do I do?   Adding the lshw -c video ouput:    *-display UNCLAIMED             description: 3D controller        product: GM108M [GeForce 940MX]        vendor: NVIDIA Corporation        physical id: 0        bus info: pci@0000:02:00.0        version: a2        width: 64 bits        clock: 33MHz        capabilities: cap_list        configuration: latency=0        resources: memory:f1000000-f1ffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:d000(size=128)   *-display        description: VGA compatible controller        product: Intel Corporation        vendor: Intel Corporation        physical id: 2        bus info: pci@0000:00:02.0        version: 06        width: 64 bits        clock: 33MHz        capabilities: vga_controller bus_master cap_list rom        configuration: driver=i915_bpo latency=0        resources: irq:128 memory:f0000000-f0ffffff memory:e0000000-efffffff ioport:e000(size=64)

(Ubuntu 16.04) (GF9600GT)  Should I remove Nouveuau before install NVIDIA driver?


A particular disease affects 0.1% of the population.   The test is 95% accurate.   You test positive.   What is the chance that you have the disease?  How I approached the problem: Since I already tested positive, and the question clearly states that the test is 95% accurate, there should be a 95% probability that I have the disease. But, a YouTube  says that the chance I have the disease is 2%. How is my reasoning wrong?

We are conducting a test on a rare disease. A positive result means that, according to the test, the subject is infected. The following characteristics are known about the test and the disease: If a person is infected, the person has a $95\%$ chance of testing positive. When a healthy person is tested, the test has a $99\%$ chance of giving a negative result. A mere $0.1\%$ of the population is infected with the disease. If a person is tested positive for the disease. What is the probability that the person actually has the disease? I don't understand how to write the conditional probabilities if someone can explain to me than I should know how to solve it, but I'm not sure how to convert the text into the mathematics language.


I would like to create a vertical bar, as is, in a \textbf{#1} command:  MWE:   \documentclass{article} \begin{document} \textbf{Hello|there}  \texttt{Hello|there} \end{document}   which produces this:    How can I get the vertical bar working in bold-series?  EDIT: I do not want to change the | char (I want to keep using |).

How to insert pipe symbol | in TeX (LaTeX)?  I have tried this sample with pdflatex tmp.tex  \documentclass{extarticle} \begin{document} \textpipe \end{document}   And it give undefined control sequence error  This is pdfTeX, Version 3.1415926-1.40.10 (TeX Live 2009/Debian) restricted \write18 enabled. entering extended mode (./tmp.tex LaTeX2e <2009/09/24> Babel <v3.8l> and hyphenation patterns for english, usenglishmax, dumylang, noh yphenation, loaded. (/usr/share/texmf-texlive/tex/latex/extsizes/extarticle.cls Document Class: extarticle 1996/10/08 v1.0 Non Standard LaTeX document class (/usr/share/texmf-texlive/tex/latex/base/size10.clo) (/usr/share/texmf-texlive/tex/latex/base/exscale.sty)) No file tmp.aux. ! Undefined control sequence. l.3 \textpipe


I need a personal ID generator for Bulgarian IDs and since our IDs are 10 digits long I can't do it with an int number and I need some suggestions. I tried with this code but it doesn't work. It also needs to be above 999999999 or below 9999999999.  static class ID {     Random random = new Random();     long perID = random.nextLong(999999999); }

How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum);  Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum =  minimum + i;  Bug: randomNum can be smaller than minimum.


I have an java application.And I use Runtime.getRuntime().exec for call a batch file.When I call a linux batch file using with Runtime.getRuntime().exec the batch file could not find its own directory. I use pwd command in batch file but it returns application path. I need batch file's own  physical path from itself. How can I do this?

How do I get the path of the directory in which a  script is located, inside that script? I want to use a Bash script as a launcher for another application. I want to change the working directory to the one where the Bash script is located, so I can operate on the files in that directory, like so: $ ./application


I was recently pointed to this question () and wanted to get some clarification. LinkedList<Integer> test1 = new LinkedList<Integer>();  List<Integer> test2 = new LinkedList<Integer>();   From what I've read, the first LinkedList/List determines what methods can be used. So for test1, you can do test1.peek() while you can't for test2. Is that because, for test2, that you are creating a LinkedList but going to be implementing the methods of the List interface? In other words, for test2, you've created a LinkedList with a prev & next node but are choosing to implement the methods outlined in the List interface? Guess I'm a bit confused because I thought LinkedList is a class that implements the List interface, but for test2, we're creating a LinkedList and implementing a List again?

I have seen this mentioned a few times and I am not clear on what it means. When and why would you do this?   I know what interfaces do, but the fact I am not clear on this makes me think I am missing out on using them correctly.   Is it just so if you were to do:  IInterface classRef = new ObjectWhatever()   You could use any class that implements IInterface? When would you need to do that? The only thing I can think of is if you have a method and you are unsure of what object will be passed except for it implementing IInterface. I cannot think how often you would need to do that.   Also, how could you write a method that takes in an object that implements an interface? Is that possible?


I am using natbib for citation like so:  \usepackage[super, comma, numbers, square, sort]{natbib}   With normal citations, e.g.   \cite{some-ref}    this works as expected. But when i try to pass an optional argument like so:  \cite[Page 2]{some-ref}   it comes out wrong. The reference-number is put into brackets with superscript, but the optional argument is put outside of the brackets like normal text, like if I would write   \cite{some-ref}Page 2   How can I fix this? I want to have the whole citation, including the optional argument as superscript.

I'm with an annoying problem with natbib. When the super parameter is used, the citation happily goes superscript but the page or chapter number doesn't.  \documentclass{article} \usepackage[numbers, square, super]{natbib} \begin{document}     Some information.\cite[p.~56]{who09}      \begin{thebibliography}{0}         \bibitem{who09} Who J F. Nice Book. 2009.     \end{thebibliography} \end{document}   The above example shows the page number into normal text instead of superscript. Removing super the page goes into brackets.


Let $V$ be an inner product space and $T:V \to V$ be a linear operator. Show that $N(T)^\perp=R(T^*)$.  Trial: $N(T)=R(T^*)^\perp$ since $y \in N(T) \iff Ty=0 \iff \langle x,Ty \rangle=0 \quad \forall x \iff \langle T^*x,y \rangle=0 \quad \forall x \iff y \in R(T^*)^\perp$. Taking $\perp$ both sides, $N(T)^\perp=(R(T^*)^\perp)^\perp$. I know that for finite dimensional $W$, $(W^\perp)^\perp=W$. But in this case it may not be finite dimensional. Does it need another approach?

How can I prove that, if $V$ is a finite-dimensional vector space with inner product and $T$ a linear operator in $V$, then the range of $T^*$ is the orthogonal complement of the null space of $T$?  I know what I must do (for a $v$ in the range of $T^*$, I have to show that $v\perp w$ for every $w$ in $\ker(T)$ and then do the opposite), but I don't know how to show that this inner product is zero.


Let $S_n= X_1+\ldots+X_n$ where $X_i$ are independent, with mean $0$ and finite variance. Suppose $|X_m|\leq K$ $\forall m$. Use that $S_n^2-var(S_n)$ is a martingale to prove that for any $x>0$ $$ \mathbb{P} \left(\max_{1\leq m\leq n}|S_m|\leq x \right) \leq \frac{(x+K)^2}{var(S_n)} $$  I have shown that $S_n^2-var(S_n)$ is a martingale but I don't know how to proceed since usual inequalities work in the opposite direction

Let $S_n=\zeta_1+...+\zeta_n$ where $\zeta_i$ are independent with $E\zeta_i=0, E\zeta_i^2=\sigma_i^2<\infty, |\zeta_i|<K$.  Then, $P(\max_{1 \leq m  \leq n}|S_m| \leq x) \leq (x+K)^2/\operatorname{var}(S_n)$.  How do we show this?  The hint says that I should use the fact that $S_n^2-\sum_{m \leq n}\sigma_m^2$ is a martingale. But I am totally clueless....  Any hint would be appreciated! Thanks and regards.


Hope this isn't a duplicate.  Let $f : \Bbb R \to \Bbb R$ be a function. Let $D(f) = \{x \in \Bbb R : f$ is discontinuous at $x\} $ and $N(f) = \{x \in \Bbb R : f $ is not differentiable at $x \}$ .   It is easy to prove that $D(f)$ is an $F_{\sigma}$ set i.e. can be expressed as a (at most) Countable union of closed sets (possibly empty). Now considering $N(f)$ , since by definition, $D(f) \subseteq N(f) $ , it follows that $N(f)$ contains an at most Countable union of closed sets(possibly empty). In case we further assume that    But my question is what can be said about the structure of $N(f)$ when $f$ is considered in full generality i.e. all we are assuming is that  $f : \Bbb R \to \Bbb R$ is a function and no other added restriction is posed on $f$ .

If $f : \mathbb{R} \to \mathbb{R}$, define $C(f) = \{ x : f \text{ is continuous at } x \}$ and $D(f) = \{ x : f \text{ is differentiable at } x \}$. I have seen it proved that:   $C(f)$ is a $G_\delta$ set. For any $G_\delta$ set $A \subset \mathbb{R}$, there exists a function $f : \mathbb{R} \to \mathbb{R}$ such that $C(f)=A$.   I suspect there is a related characterization for $D(f)$. I see that a related question was asked at , where the accepted answer implies that $D(f)$ is a $G_{\delta \sigma \delta}$ set.   Is this optimal, that is, does there exist $f$ such that $D(f)$ is $G_{\delta \sigma \delta}$ and not $G_{\delta \sigma}$? If so, can an example be given? Conversely, given any $G_{\delta \sigma \delta}$ set $A \subset \mathbb{R}$, does there exist $f$ such that $D(f)=A$?


I've verified that "Notify me of new Ubuntu version" is set to "For long-term support versions" in Software & Updates. Yet when I run do-release-upgrade I get "No new release found." Please help.

I'm following the , but on launching the upgrade tool I get this response:  Checking for a new ubuntu release No new release found   Am I doing something wrong? Is there a workaround?


i tried to install oracle-xe-11.2.0-1.0.x86_64 on ubuntu 20.04  i have gone through a lot of installation steps from many resources , many of them asked to unzip the oracle-xe-11.2.0-1.0.x86_64.rpm.zip file on first step  but when i downloaded from oracle website the file was in .rpm format instead of .rpm.zip   please help me out with this.

I have a burning desire to install RPMs onto my Ubuntu installation - is this possible? Can I use Yum - or another RPM Package Management tool?


I installed Ubuntu 12.10 (not realizing it was an old unsupported version). I lost access to windows 7 at boot up (it messed up the boot up drivers) have since downloaded Ubuntu 14.04.3 How do I install the latter version?

I dual booted ubuntu 11.04/11.10 a while ago with a USB stick and i want to uninstall it.   I would like to completely uninstall the old version and get 12.04.  I have a 64 bit laptop. Please help!


It has been several months since I upgraded my Ubuntu version. How can I find the date that I upgraded?  It has been suggested to look in the directory /var/log/dist-upgrade but this directory is empty on my system.

I've upgraded to Ubuntu 12.04 and did it . I didn't look at the "packages to remove" section before clicking next - I've done Ubuntu upgrades many times and assumed it was just the normal set of obsolete library packages etc. But I do tend to watch the terminal text go by and see what it's doing, and I saw it removing a number of packages I wanted. I guess these are packages that aren't on the CD that can't co-exist with the new Ubuntu.  Anyway, I want to find which packages have been removed. So does the update log get saved somewhere?  Then I can start doing some grepping on it and then reinstall the packages I did want.


As is well known pretty much all integration rules come from differentiation rule, so the substitution rule comes from the chain rule, and the integration by parts comes from the product rule, indeed $$(uv)'=uv'+vu'\implies\int uv'dx=uv-\int vu'dx.$$ But I never saw a rule that used the Over Rule $$(u/v)'=\frac{u'v-v'u}{v^2}=\frac{u'v}{v^2}-\frac{v'u}{v^2}=\frac{u'}{v}-\frac{uv'}{v^2}\implies \int \frac{u'}{v}dx=\frac uv+\int\frac{uv'}{v^2}dx$$ Is this like a new rule or does it already exist?

When teaching the integration method of u-substitution, I like to emphasize its connection with the chain rule of integration. Likewise, the intimate connection between the product rule of derivatives and the method of integration by parts comes up in discussion.      Is there an analogous rule of integration for the quotient rule?     Of course, if you spot an integral of the form $\int \left (\frac{f(x)}{g(x)} \right )' = \int \frac{g(x) \cdot f(x)' - f(x) \cdot g(x)'}{\left [ g(x)\right ]^2 }$, then the antiderivative is obvious. But is there another form/manipulation/"trick"?


Here is the python code   import re  x = "'hey! hii. How are You? This is sAM'"  d = re.findall(r"[\w']+|[.,!?;]", x)   and the output is   ["'hey", '!', 'hii', '.', 'How', 'are', 'You', '?', 'This', 'is', "sAM'"]   what I want is   [ " ' ", "hey", '!', 'hii', '.', 'How', 'are', 'You', '?', 'This', 'is', "sAM", " ' " ]   i.e i want this ( ' ) to be separated too.  Can you help me figure it out? how can we do this in the same regex

I'm trying to split a string up into words and punctuation, adding the punctuation to the list produced by the split.  For instance:  >>> c = "help, me" >>> print c.split() ['help,', 'me']   What I really want the list to look like is:  ['help', ',', 'me']   So, I want the string split at whitespace with the punctuation split from the words.  I've tried to parse the string first and then run the split:  >>> for character in c: ...     if character in ".,;!?": ...             outputCharacter = " %s" % character ...     else: ...             outputCharacter = character ...     separatedPunctuation += outputCharacter >>> print separatedPunctuation help , me >>> print separatedPunctuation.split() ['help', ',', 'me']   This produces the result I want, but is painfully slow on large files.  Is there a way to do this more efficiently?


I want an item within the reach of my hands. Which one of the following sentences is correct? Please explain.   Keep it close TO hand?! Keep it close AT hand?!

What's the difference between at hand, on hand and in hand? At hand seems to me as if you have something in reach. On hand is if you have something in stock. And in hand can be used as if you have more time at your disposal.


I have seen many answers pointing out use (?s) ahead of reg expression but it will match more than I expect. I'm using search in Eclipse Neon.  Ex:  Line 1: String[] str1 = new String[] {"a", "b", Line 2:     "c", "d"}; Line 3: String[] str2 = new String[] {"aa", "bb", Line 4:     "cc", "dd"};   Regex (?s)(\w+)\[\] (\w+) = new .+ (\{.*\}); will match line 1  to line 4, stops matching in the last };, while I want to make the match stop in the first }; so line1\2 and line3\4 can be matched separately.

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


I'm trying to make a 2d array using lists. From input I have a tuple with the specs of the lines and the columns. Something like this.  ((1, 2, 3, 4, 5), (9, 8, 7, 6, 5))   This means that i need a list like this:  [[0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0]]   (A 5x5 matrix)  to make the matrix, since i don't know the lenth of the specs tuple. I made a constructor to make the matrix. Something like this: (t is the specs tuple)  t=[[0] * len(t[0])] * len(t[1])   This makes exacly what I want, but when I try to change a value this happens: (y is the matrix)  >>>y[0][1]=2 >>> y [[0, 2, 0, 0, 0], [0, 2, 0, 0, 0], [0, 2, 0, 0, 0], [0, 2, 0, 0, 0], [0, 2, 0, 0, 0]]   It changes all the [1] index of all the lines. Why is it doing this?

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


How can I make a GameObject attach (or "stick") to another GameObject after collision? The problem: I want the GameObject to attach after collision even if it changes scale.  What I have tried:  protected Transform stuckTo = null; protected Vector3 offset = Vector3.zero;  public void LateUpdate() {     if (stuckTo != null)         transform.position = stuckTo.position - offset; }   void OnCollisionEnter(Collision col) {     rb = GetComponent<Rigidbody>();     rb.isKinematic = true;      if(stuckTo == null         || stuckTo != col.gameObject.transform)         offset = col.gameObject.transform.position - transform.position;      stuckTo = col.gameObject.transform; }   This code makes a GameObject attach perfectly after collision. But when that GameObject changes scale (while it's attached), it visually no longer looks attached to whatever it collided with. Basically, this code makes the GameObject stick with only the original scale at the moment of the collision. How can I make the GameObject always stick to whatever it collided with? And with whatever scale it has during the process?

Currently, I am using the following code to make objects stick to other gameObjects.  rb = GetComponent<Rigidbody>(); rb.isKinematic = true; gameObject.transform.SetParent (col.gameObject.transform);   It works perfectly, but it causes many other problems... For example, after colliding, it can no longer detect collisions... Is there an alternative to this code (which makes a gameObject stick to another one after collision)?


I'm getting dpkg: error processing package mysql-server-5.7 but mysql-server-5.7 package is working and I am able to login to the DB and chagned the password. But every time I run apt-get I am getting errors. This is a new server  Any suggestion on how to fix this? Since this is a new installation I can repair mysql if needed. I won't be able to deal with it once I load the data into mysql DB.  root@hostname:~# apt-get install htop Reading package lists... Done Building dependency tree Reading state information... Done The following NEW packages will be installed:   htop 0 upgraded, 1 newly installed, 0 to remove and 251 not upgraded. 2 not fully installed or removed. Need to get 76.4 kB of archives. After this operation, 215 kB of additional disk space will be used. Get:1 http://us.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 htop amd64 2.0.1-1ubuntu1 [76.4 kB] Fetched 76.4 kB in 0s (151 kB/s) Selecting previously unselected package htop. (Reading database ... 63166 files and directories currently installed.) Preparing to unpack .../htop_2.0.1-1ubuntu1_amd64.deb ... Unpacking htop (2.0.1-1ubuntu1) ... Processing triggers for mime-support (3.59ubuntu1) ... Processing triggers for man-db (2.7.5-1) ... Setting up mysql-server-5.7 (5.7.30-0ubuntu0.16.04.1) ... Renaming removed key_buffer and myisam-recover options (if present) mysql_upgrade: Got error: 1045: Access denied for user 'debian-sys-maint'@'localhost' (using password: YES) while connecting to the MySQL server Upgrade process encountered error and will not continue. mysql_upgrade failed with exit status 11 dpkg: error processing package mysql-server-5.7 (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of mysql-server:  mysql-server depends on mysql-server-5.7; however:   Package mysql-server-5.7 is not configured yet.  dpkg: error processing package mysql-server (--configure):  dependency problems - leaving unconfigured Setting up htop (2.0.1-1ubuntu1) ... No apport report written because the error message indicates its a followup error from a previous failure.                                                                                Errors were encountered while processing:  mysql-server-5.7  mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1)   apt list --installed | grep mysql  WARNING: apt does not have a stable CLI interface. Use with caution in scripts.  mysql-client-5.7/xenial-updates,xenial-security,now 5.7.30-0ubuntu0.16.04.1 amd64 [installed,automatic] mysql-client-core-5.7/xenial-updates,xenial-security,now 5.7.30-0ubuntu0.16.04.1 amd64 [installed,automatic] mysql-common/xenial-updates,xenial-updates,xenial-security,xenial-security,now 5.7.30-0ubuntu0.16.04.1 all [installed,automatic] mysql-server/xenial-updates,xenial-updates,xenial-security,xenial-security,now 5.7.30-0ubuntu0.16.04.1 all [installed] mysql-server-5.7/xenial-updates,xenial-security,now 5.7.30-0ubuntu0.16.04.1 amd64 [installed,automatic] mysql-server-core-5.7/xenial-updates,xenial-security,now 5.7.30-0ubuntu0.16.04.1 amd64 [installed,automatic]

Im trying to install mysql and I get the error: mysql_upgrade: Got error: 1045: Access denied for user 'debian-sys-maint'@'localhost' (using password: YES) while connecting to the MySQL server  After some searching, I find this is perhaps giving access to debian-sys-maint, so I did this: sudo cat /etc/mysql/debian.cnf  Then set the debian password in mysql: mysql -u root -p <password> GRANT ALL PRIVILEGES ON *.* TO 'debian-sys-maint'@'localhost' IDENTIFIED BY 'password-here';  Then I restart: sudo /etc/init.d/mysql restart  And try and configure again: sudo dpkg --configure -a  I get the same error.


Assume I have a function like this :  int recursivefunction (int n) {     if (n>10) return n; /* terminal case */     elseif (n>5) return n*recursivefunction(n-1); /* non tail call*/     else return recursivefunction(n-1); /* tail call   Will the third recursive call be optimized as a tail call ? If not why not ? We could replace this third return statement by an assembly code that clears the current function stack frame, except for local variables passed to the next call, and a goto to the adress of the function, this way no space on the stack is reserved.

It seems to me that it would work perfectly well to do tail-recursion optimization in both C and C++, yet while debugging I never seem to see a frame stack that indicates this optimization. That is kind of good, because the stack tells me how deep the recursion is. However, the optimization would be kind of nice as well.  Do any C++ compilers do this optimization? Why? Why not?  How do I go about telling the compiler to do it?   For MSVC: /O2 or /Ox For GCC: -O2 or -O3   How about checking if the compiler has done this in a certain case?   For MSVC, enable PDB output to be able to trace the code, then inspect the code For GCC..?   I'd still take suggestions for how to determine if a certain function is optimized like this by the compiler (even though I find it reassuring that Konrad tells me to assume it)  It is always possible to check if the compiler does this at all by making an infinite recursion and checking if it results in an infinite loop or a stack overflow (I did this with GCC and found out that -O2 is sufficient), but I want to be able to check a certain function that I know will terminate anyway. I'd love to have an easy way of checking this :)    After some testing, I discovered that destructors ruin the possibility of making this optimization. It can sometimes be worth it to change the scoping of certain variables and temporaries to make sure they go out of scope before the return-statement starts.  If any destructor needs to be run after the tail-call, the tail-call optimization can not be done.


Is there an easy way to add four empty lines between each sentence.   For example, this paragraph:  This combination of vitamins and selected minerals is used to prevent or treat vitamin  deficiency due to poor eating habits, problems that affect the body's ability to absorb nutrition from food, or increased need for vitamins and minerals due to stress  or illness. Vitamins are needed for the body to function well. This vitamin/mineral combination contains high levels of B vitamins (e.g., folic acid,  niacin, B-1, B-2, B-6, and B-12) and vitamin C. It also contains other vitamins (A, D, and E) and minerals such as zinc. This medication does not contain iron and has only a  small amount of calcium. Therefore, it should not be used to treat "iron-poor" blood  (anemia) or to prevent osteoporosis.   How I can make it:  This combination of vitamins and selected minerals is used to prevent or treat vitamin      deficiency due to poor eating habits, problems that affect the body's ability to absorb nutrition from food, or increased need for vitamins and minerals due to stress      or illness. Vitamins are needed for the body to function well.     This vitamin/mineral combination contains high levels of B vitamins (e.g., folic acid,      niacin, B-1, B-2, B-6, and B-12) and vitamin C. It also contains other vitamins (A, D, and E) and minerals such as zinc. This medication does not contain iron and has only a      small amount of calcium. Therefore, it should not be used to treat "iron-poor" blood      (anemia) or to prevent osteoporosis.   I would like:  1-  to add four blank spaces between each line.  2-  to add one blank space after the first line then every four spaces

I want to insert 5 blank lines after every line in my input file.  foo.txt:  line 1 line 2 line 3   out.txt:  line 1      line 2      line 3          ...   Solaris 5.10, nawk or sed.


Take a look at .   He has bronze tag badge for , but not for  and (for those tags he has ).   The score calculation looks like wrong,  .    But, it shows 216 for .

What are badges? How do users get badges? How can users get tag badges? Can badges be lost/revoked/taken away after they are awarded? If so, how and when? How can I suggest a new badge?   For more information, see "" and the  in the .


I have schengen visa , single entry issued by Italian consulate in Palestine. I want to visit Italy and Bulgaria. It would be my first time visiting Europe.  Should go to Italy first and then go to Bulgaria (notice that my visa is one entry and Bulgaria is not a schengen zone)? Or I can go to Bulgaria first, finish my work, then go to Italy?

Is it possible to enter Bulgaria with a valid single entry Schengen visa? I plan to travel from Kenya to Bulgaria then to Greece. I know it is not possible to go to Greece then Bulgaria because the visa will be invalid but would like to know if I can travel to Bulgaria then Greece on the single entry Schengen visa.


Which usage of the prefix, "Meta" is correct, "Metaprogramming" or "Meta-programming"? Should the word be hyphenated or not?

As a non-native speaker of English and an engineer by training, I always get confused about hyphenation and almost always end up referring to Google every time I need to make that decision.  Does anybody know of a concise, comprehensive style guide to hyphenation that explains this rather complex issue, once and for all?


Say I have an array of key-value pairs with non-numerical keys. If I am going to be using those keys as values in an SQL INSERT statement, is it important to sanitize them as well?  Something like:  $food = array('fruit'=>'apple', 'veggie'=>'tomato', 'bread'=>'wheat'); foreach($food as $foodType => $nameOfFood) {     $nameOfFood = stripslashes($nameOfFood);     $foodType = stripslashes($foodType); //Is this necessary?     $query = "INSERT INTO Foods(FoodType, NameOfFood) VALUES ($foodType, $nameOfFood)";     // Execute query }   If the $food array was populated through a POST statement, would sanitizing the keys be a concern?

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


Can a body 'X' apply gravitational force On a Body 'Y' without being itself acted by a gravitational force By 'Y'?

My father explained to me how rockets work and he told me that Newton's Third Law of motion worked here. I asked him why it works and he didn't answer. I have wasted over a week thinking about this problem and now I am giving up. Can anyone explain why Newton's Third Law works? For reference, Newton's third law:  To every action there is always opposed an equal reaction: or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.


Majority of the time I am able to use @ to respond back to a user on SO, however in some instances it does not work? Any ideas why this might be?

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


From a user that is part of the sudoers group, I can normally run any command by doing sudo <command>  But the following command fails stating "Permission denied"  sudo echo "myhostname" > /etc/hostname   It doesn't even ask me for the password. How do I change the hostname ?

When you attempt to modify a file without having write permissions on it, you get an error:  > touch /tmp/foo && sudo chown root /tmp/foo > echo test > /tmp/foo zsh: permission denied: /tmp/foo   Sudoing doesn't help, because it runs the command as root, but the shell handles redirecting stdout and opens the file as you anyway:  > sudo echo test > /tmp/foo zsh: permission denied: /tmp/foo   Is there an easy way to redirect stdout to a file you don't have permission to write to, besides opening a shell as root and manipulating the file that way?  > sudo su # echo test > /tmp/foo


I'm troubled with the following question:  $V_1$ and $V_2$ are subspaces of $K$-vector space $V$. Show that $V_1 \cup V_2 = V$ implies $V_1 = V$ or $V_2 = V$.  I don't understand why $V_1$ or $V_2$ is supposed to equal $V$ when $V_1 \cup V_2 = V$ shows that they are subsets.

I'm having a difficult time understanding this statement. Can someone please explain with a concrete example?


My iPhone is in recovery mode and I want to recover some photos. Does anyone know if dr.fone works? I don't want to pay for something that doesn't do the job.

I have an iphone 4 that is stuck in restore mode after trying to update to ios 6 wirelessly.  Unfortunately, I do not have a recent itunes backup of this phone.  Is there any way to recover my photos from this device before I try to restore it?  Will restoring it wipe all the data on the phone?


I am trying to set my background using setbg with the following command xsetbg -fullscreen Libraries/Pictures/Pictures/1998_Chicago/565462-R10-04-21.jpg  When I do, nothing happens and the return code is 0. The file and path are valid.  I found this link         and tried the command  gsettings set org.gnome.settings-daemon.plugins.background active true   mentioned in the thread but it did not help. I have the latest mate-settings-daemon so that wasn't the issue. Any ideas?

I have a script that updates my desktop background every day with the NASA APOD. Since upgrading to 11.10, that script stopped working, presumably because I'm using gconftool-2 to actually update the desktop background. Is there a new way to do this under Unity?


private static final long serialVersionUID = 1L; (Only 1L other than the other numbers) SUID is not declared for a class (Of courese, implements Serializable)     I think Both of them seem to make the serialVersionUID value automatically. Isn't it?  I wonder what the difference is.    Help would be highly appreciated.

Eclipse issues warnings when a serialVersionUID is missing.       The serializable class Foo does not declare a static final   serialVersionUID field of type long   What is serialVersionUID and why is it important?  Please show an example where missing serialVersionUID will cause a problem.


I have a model I created with bones from Mixamo. The FBX has embeded textures. I want to rename the bones in the model to get rid on the Mixamo in the beginning of each bone name. (this is find with Mixamo). I removed the Mixamo from the names, but then I export as FBX, the textures are gone. I am wondering how to reapply the textures to the model, or how to save the FBX with the textures. Thanks for any help.

I used node textures in a mesh I exported to .FBX.  I then imported it into Unreal Engine 4 and it didn't import any textures; I clicked the Upload Textures option in Unreal Engine.  Is there something I'm doing wrong or is it Blender?


I'm writing a scientific paper, I want to use i.e. or that is to clarify a term. Are they both correct or either?

Is there any (even the most subtle) difference between the meaning (or connotation) of that is and i.e.?  I used to be convinced that they were synonyms, until an editor of a scientific journal changed all occurrences of i.e. into that is.


I understood that quantum field theory is essentially based on a problematic mathematical basis. Can someone please explain what is the fundamental problem to formulate QFT as a rigorous mathematical theory? It's clear that it has to do with renormalization but similar techniques are already exist in analytically number theory (and are considered to be a mathematical theory).

I'm wondering about current efforts to provide mathematical foundations and more solid definition for quantum field theories. I am aware of such efforts in the context of the simpler topological or conformal field theories, and of older approaches such as algebraic QFT, and the classic works of Wightman, Streater, etc. etc . I am more interested in more current approaches, in particular such approaches that incorporate the modern understanding of the subject, based on the renormalization group. I know such approaches exists and have had occasions to hear interesting things about them, I'd be interested in a brief overview of what's out there, and perhaps some references.  Edit: Thanks for all the references and the answers, lots of food for thought! As followup: it seems to me that much of that is concerned with formalizing perturbative QFT, which inherits its structure from the free theory, and looking at various interesting patterns and structures which appear in perturbation theory. All of which is interesting, but in addition I am wondering about attempts to define QFT non-perturbatively, by formalizing the way physicists think about QFT (in which the RNG is the basic object, rather than a technical tool). I appreciate this is a vague question, thanks everyone for the help.


So I'm facing a regression problem where I have a categorical features (factor) where the levels are very commonly different between the training set and the test set.  I have multiple measurements per subject, where the context where the measurement was made changes constantly and is represented by the current_context variable. I would like to measure how the context affects the measurement on a per subject basis, and try to predict new values for the response, given the context and other, fixed, predictors.  Example:  Training:  subject_id current_context response 1 C15 55 1 D46 44 1 A416 99 ... 10^6 G426 44 10^6 G426 44  Test: subject_id current_context response 1 C15 65 1 D55 55 1 E416 101 ... 10^6 G426 44 10^6 E417 65   One solution for this would be that I could create different models (kind of like  in NLP) and fall back to simpler models until all the features are available. In the example I would have one model trained on all the features, and two more trained only on one feature at a time. But that's an engineering overhead I would like to avoid.  Another solution as suggested is to use hierarchical modeling. This is probably impossible in my case, as I would like to have the subject_id as a random effect, which could be in the millions and that doesn't scale AFAIK. Another problem I've noticed when trying that is that because the current_context can also have hundreds of thousands of values, it leads to computational issues as well (I get the error that linpack cannot create a matrix of adequate size)  So I was wondering if there are (regression) models that have this kind of robustness built in, i.e. are able to produce estimates for the dependent even if some of the features used during training are missing, or if new levels appear in factor.

I originally posted this in stackoverflow (as given ) but was told to try here since it might be more relevant here. I am very new to statistics and R in general so my question might be a bit dumb, but since I cannot find my solutions online I thought I should try ask it here.  I have a data frame dataset of a whole lot of different variables very similar to as follows:   Item | Size   | Value    | Town ---------------------------------- A     |  10    |   800   | 1 B     |  11    |   100   | 2 A     |  17    |   900   | 2 D     |  13    |   200   | 3 B     |  15    |   500   | 1 C     |  12    |   250   | 3 E     |  14    |    NA   | 2 A     |        |   800   | 1 C     |        |   800   | 2   Basically, I have to try and 'guess' the Size based on the type of Item, it's Value, and the Town it was sold in, so I think a regression method would be a good idea.  I now use a regression as follows:  lm(Size ~ factor(Item) + factor(Town) + Value,...)  The problem however, occurs when I try and predict the Size using this model. I have the following lines of code:  pmodel <- lm(Size ~ factor(Item) + factor(Town) + Value,...) prediction <- predict(pmodel, dataset2)   (where dataset2 is a subset of dataset which has all the empty "Size" values which I want to predict)  But this now comes up with the error:  Error in model.frame.default(Terms, newdata, na.action=na.action, xlev = object$xlevels): factor factor(Town) has new levels   Is there any way around this, or is there any way I can get the model to make prediction based on the other values if it encounters a 'level' which is not in the original dataset?


How to establish the following identities without the help of calculus:  For positive integer $n, $ $$\sum_{1\le r\le n}\frac{(-1)^{r-1}\binom nr}r=\sum_{1\le r\le n}\frac1r $$  and  $$\sum_{0\le r\le n}\frac{(-1)^r\binom nr}{4r+1}=\frac{4^n\cdot  n!}{1\cdot5\cdot9\cdots(4n+1)}$$


Is the following result true? If $i^4 = 1$, $(i^4)^{1/4} = 1^{1/4}$, and$i = 1$, then won't it disprove $i = (-1)^{1/2}$? If no, give a proper reason?  Can this be a contradiction to complex numbers?

I know there must be something unmathematical in the following but I don't know where it is: \begin{align} \sqrt{-1} &= i \\\\\ \frac1{\sqrt{-1}} &= \frac1i \\\\  \frac{\sqrt1}{\sqrt{-1}} &= \frac1i \\\\  \sqrt{\frac1{-1}} &= \frac1i \\\\  \sqrt{\frac{-1}1} &= \frac1i \\\\  \sqrt{-1} &= \frac1i \\\\  i &= \frac1i \\\\  i^2 &= 1 \\\\  -1 &= 1 \quad !!? \end{align}


I'm using macbook retina mid 2014 with storage capacity 128GB. When i check my storage About This Mac > Storage, its showing uses of movies occupying 3.96GB. I check all folders individually but i can't find a single video file.  And also why the "other" section occupying 56.04 GB of storage. Here is the screenshot.

I have a Macbook Air(6,2) with 120 GB SSD. When I checked About This Mac --> Storage, I see inconsistent information.    It says 87.89 GB free but Apps take up 92.65 GB. So there should only be about 30 GB free according to the graphic. However, I believe the graphic is wrong because OmniDiskSweeper says Macintosh HD is ~30GB.   Why do the graphic and numbers disagree?


I will take an example. Stack Overflow. There are a lot of times when users and moderators tell us to resolve certain unsupported issues (i.e. topics which are unaccepted as questions in the site's expected format) in . There are a lot of times when an extended comment discussion ends with one of the users agrees to go to the chatroom when the Stack Exchange site tells them the discussion went too long (or perhaps a moderator moves the whole conversation to a new channel). I know, and can guess, how to enter the chat room by typing the URL. It is hard to forget, specially if the Stack Exchange system tells you to do that and provides a link. However, in the UI I cannot find any reference to the chat. No button. No link. No menu item. I think it will be useful if among the buttons:  Questions | Jobs | Tags | Users | Badges | Ask Question  One more button was added being Chat (perhaps next to Questions). Additionally, a brief list of newest or hottest chat rooms would be useful on the main site page (this is: the main questions listing of the respective site) so the chat is encouraged. Take an example: a user wants to discuss about which  library is better among many possibilities. Such a question is disallowed unless specific criteria are given, in the Q&A. However, the user thinks, somehow, answering the question will bring him value, somehow. The following occurs:  The user posts the question to Stack Overflow Q&A. The question is closed, since it is not constructive (assume the case no specific criteria was given, but just comparing for a better library). The user wants to ask about this kind of questions and close reasons. Experienced users and moderators tell him that Chat is available for those questions (the third place). The user asks himself: "Chat? WTF? Is that stuff visited by people willing to answer questions and address problems?"  And perhaps, by connecting the chat with more than one link (e.g. as I said: by notifications or telling what new channels do exist), no doubt will exist that it is a more useful place than just a pile of migrated comments. What do you think? Could the chat be improved, promoted, and more accessible to users so they recognize it as an existing part of the site?

In the new header could we please move the chat link back to where it was? (One click away)  As a daily frequent to the JavaScript room that's the one link I'd love to have visible 100% of the time.  Aside from that, I actually love the new header. (Maybe take it a step further an add a customizable header with (X) link spots for your most used links?)  Just my thoughts


All I remember is that it had 3 parts, and the first part was entitled "A Perfect Warrior".  The bad guy was named Odal.  The hero was a recent graduate of a sort of police academy for outer space.  He was well-intentioned, idealistic, and a total klutz.  The story line involved telepathy and some kind of mind machine that amplified it.  Any help would be much appreciated.  The book was probably written in the late 60s or early 70s.

The story begins in media res with as the viewpoint character fights a duel on a frozen planet.  They combatants are wearing something between a power suit and a single-person armoured vehicle; visibility is almost zero and radar range is short.  The viewpoint character knows what to expect, how to set his bombs for best effect, but he keeps finding his opponent not where he expects.  Eventually, his opponent seeming to attack him from multiple directions at once, he loses.  We switch now to a military-type briefing taking place aboard a ship.  The protagonist is filled in on this duel, and the fact that the person who lost is catatonic.  This is not the first time his opponent has mentally damaged those he fought against; this is a problem that must be dealt with.  I believe the simulations are constructed in the mind of one or both of the duelists, which is part of why it can have such a major effect.  The antagonist represents a hostile power, and the protagonist is volunteered to fight the next duel against him.  There's probably some stuff missing here, but the protagonist is fitted with a helmet and hooked into the simulation apparatus. This duel is being fought using lances (or some kind of hand weapons) from the backs of horses (or some other riding beast), on a dusty plain.  He enters the simulation and starts riding toward his opponent.  As they approach, 2 more horsemen appear behind his opponent and fan out to the sides.  More follow, until he is facing 6 or 7 enemies.  Nonetheless, he charges, and as he does so he sees riders fanning out beside him to meet the enemy.  His opponents, not expecting an equal fight, are defeated, and he is debriefed; he was wearing a helmet/device that allowed some of his shipmates to join in the fight, while the opponent was part of a small group (siblings) who had a telepathic bond.  I would have read this in a hardcover anthology between 1978 and 1981.  Cover is forgotten.


I'm looking to be able to say something more brief than "this tool collects the minimum, median, mean, maximum, and quartiles" of a distribution.

I am looking to correctly name something.  Often when I have my data, I calculate a "value". For instance a moment like the mean value, or a quantile. Or I aggregate a continuous variable into say 5 categories. For instance, for a time series I would calculate the mean value or some wavelet coefficients.  Then I use all those "values" as input for, e.g., my regression analysis. In quantitative trading lay people call those calculated values "signal", but that sounds strange to me.  In general, what is the name for those "values"? How would a statistician name those?


I used the below code but it gives me error. Below is my code:    if(isset($_GET['tid']))         {          $id=($_GET['tid']);          $query = new EntityFieldQuery();          $query->entityCondition('entity_type', 'node');          $query->entityCondition('bundle', 'escorts_product');          $query->propertyCondition('status', 1);          $query->fieldCondition('field_product_sub_cat', 'tid', $id,'=');          $result = $query->execute();          $total=count($result); function pager_default_initialize($total, $limit = 2, $element = 0)         {           global $pager_page_array, $pager_total, $pager_total_items;          $page = pager_find_page($element);          $pager_total_items[$element] = $total;//total items          $pager_total[$element] = ceil($pager_total_items[$element] / $limit);          $pager_page_array[$element] = max(0, min($page, ((int) $pager_total[$element]) -1));          $pager_limits[$element] = $limit;          return $pager_page_array[$element];          //print "<pre>";print_r($pager_page_array[$element]);          }          print theme('pager', array('quantity',count($result)));  error on this line function pager_default_initialize($total, $limit = 2, $element = 0) ,can anyone please guide me?

I used this code to get a pager.     if (isset($_GET['tid'])) {      $id=($_GET['tid']);      $query = new EntityFieldQuery();      $query->entityCondition('entity_type', 'node');      $query->entityCondition('bundle', 'escorts_product');      $query->pager(2,1);      $query->propertyCondition('status', 1);      $query->fieldCondition('field_product_sub_cat', 'tid', $id,'=');      $result = $query->execute();     //print "<pre>";print_r($result);     }   When I used print "<pre>";print_r($result), it gave me 2 results on y page, whereas I added more than 2; this is right.   How should I get links for next page and also previous, next? Is there any other way to get a pager?