I am doing a simple multiplayer socket.io tic tac toe game. So far everything is working, however, when I try to rotate the screen I am getting a null pointer exception error. I have two override methods to save and restore the values of my player turn's boolean value.   When I try to directly set the value like this player1.setMyTurn(savedInstanceState.getBoolean("playerTurn")) It gives me a null pointer exception.   Does anyone know why?  @Override protected void onSaveInstanceState(Bundle savedInstanceState) {     super.onSaveInstanceState(savedInstanceState);     savedInstanceState.putBoolean("playerTurn", player1.isMyTurn()); }  @Override protected void onRestoreInstanceState(Bundle savedInstanceState) {     super.onRestoreInstanceState(savedInstanceState);     player1.setMyTurn(savedInstanceState.getBoolean("playerTurn")); //this seems to cause the issue }   Error:  E/AndroidRuntime: FATAL EXCEPTION: main               Process: com.twochicken.multiplayertictactoe, PID: 8612               java.lang.RuntimeException: Unable to start activity ComponentInfo{com.twochicken.multiplayertictactoe/com.twochicken.multiplayertictactoe.MainActivity}: java.lang.NullPointerException                   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)                   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)                   at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3738)                   at android.app.ActivityThread.access$900(ActivityThread.java:135)                   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1202)                   at android.os.Handler.dispatchMessage(Handler.java:102)                   at android.os.Looper.loop(Looper.java:136)                   at android.app.ActivityThread.main(ActivityThread.java:5017)                   at java.lang.reflect.Method.invokeNative(Native Method)                   at java.lang.reflect.Method.invoke(Method.java:515)                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)                   at dalvik.system.NativeStart.main(Native Method)                Caused by: java.lang.NullPointerException                   at com.twochicken.multiplayertictactoe.MainActivity.onRestoreInstanceState(MainActivity.java:416)                   at android.app.Activity.performRestoreInstanceState(Activity.java:916)                   at android.app.Instrumentation.callActivityOnRestoreInstanceState(Instrumentation.java:1138)                   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2173)                   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)                    at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3738)                    at android.app.ActivityThread.access$900(ActivityThread.java:135)                    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1202)                    at android.os.Handler.dispatchMessage(Handler.java:102)                    at android.os.Looper.loop(Looper.java:136)                    at android.app.ActivityThread.main(ActivityThread.java:5017)                    at java.lang.reflect.Method.invokeNative(Native Method)                    at java.lang.reflect.Method.invoke(Method.java:515)                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)                    at dalvik.system.NativeStart.main(Native Method)

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?


Question:  Suppose $f:\mathbb{R}\rightarrow\mathbb{R}$ is continuous.  Prove that the set of points where the derivative of $f$ exists is Borel measurable. My Thoughts:  So, we are really trying to prove that the set $A=\{x\in\mathbb{R}:f' \text{ exists}\}$ is open whenever $f$ is continuous. So, if we can show that $A$ is open, then we would be done.  But, I am not sure if I should just play with the definition of differentiability, or if there is something topological I should be considering. Any help, suggestions, ideas, etc. are greatly appreciated!  Thank you.

I came across the following challenging problem in my self-study:  Let $f: \mathbb{R} \rightarrow \mathbb{R}$ be continuous. Then the set of points where $f$ is differentiable is a measurable set.  I am having trouble thinking of where to begin in proving this result, and wanted to see if anyone visiting had some suggestions on how to proceed.


Auto login is not working in Safari browser(Version 8.0.3 (10600.3.18)) on OS X (Yosemite 10.10.2)   ie., it doesn't detect and show 'Welcome back, < user >. You've been logged in. Click here to refresh the page.'  JS and Cookies are enabled. There are no errors in the console as well.  Situation: I am logged in on meta.stackexchange.com, but it doesn't show that I am logged in when I visit stackoverflow.com & other stack exchange sites

It seems that all Stack Exchange sites do seem to be affected by a UX killing behaviour: it seems that every day you have to login again on each of them; they never remember your login.  For someone that is visiting these sites daily and a contributing a LOT, this is extremely annoying.  Is this so hard to implement? I don't remember when I had to re-login on Google or Facebook, still Stack Exchange keeps asking me to login all the time.  Affecting at least: stackoverflow.com, surperuser.com, serverfault.com, apple.stackexchenge.com, ask.ubuntu.com, ...  I tried logging in with all of these three variants, but it seems that there is no much difference between them: direct login, Google and Facebook.


bash=${BASH_VERSION%.*}; bmajor=${bash%.*}; bminor=${bash#*.} echo "BASH VERSION --- $BASH_VERSION" echo "bmajor ----- $bmajor" echo "bminor ----- $bminor"   prints,  BASH VERSION --- 4.2.46(1)-release bash --- 4.2 bmajor ----- 4 bminor ----- 2   I normally use curly brackets, {} to work with arrays. I see here, they are used for pattern matching.   How these values, ${BASH_VERSION%.*}; bmajor=${bash%.*}; bminor=${bash#*.} are evaluated? And what does the special characters, *, ., # inside {} mean?

I'm quite confused about the following regular expressions I found in a shell script:  ${0##*/} ${0%/*}   How do they work?


I just want to ask how to compare two database tables, staging vs. operational tables.   After we did the transformation and convert it to correct datatype like convert flag column (Y/N) nvarchar to bit or to int, how to compare data between the two tables?

We are migrating our database to a new schema but want to validate the data has been moved correctly.   Traditional data comparison tools can compare two databases for differences if the schemas are the same. In our case there have been changes to the table designs but all the data from the old schema is in the new one, it's just been moved around a bit, and I need to make sure it is correct. We have tens of millions of rows so manual inspection is not an option.  Are there any tools which could aid in this type of comparison?  If not are there any libraries/frameworks which could help kick start the development of a custom solution?  I'm happy to use a database specific solution if necessary, in this case for SQL Server 2008.  My soluton: I'm comparing the two data sets by creating a VIEW of each table on the old database with the same fields as the new database table.   I then compare the data using the technique described here:   I'm lucky in this migration as the overall table structure is similar to the old database, with fields moved from one table to another, dropped or added. In the case of the dropped and added there is nothing to compare, for the fields which have moved or been aggregated I do calculations in the view to provide the correct information for comparison.  The UNION comparison shows me only the rows with differences, so as soon as the data is correct I get an empty result set.


I have a old laptop with the following specifications:  AMD Brazos Dual core 1Ghz 4GB ram  Will my laptop be able to run Ubuntu? If yes then which version will I need to install?

I have a device on which I would like to install Ubuntu. How do I find out if Ubuntu will work on it?


Why it is necessary to put two 120 ohm termination resistors at each end of CAN transmission line respectively? Does it make an equivalent resistance of 60 ohm? (parallel resistors). Is it OK to put only a single resistor at any end or in middle of this transmission line?

I know the reasons for using terminating resistors on a  and how important it is.  But why 120 ohm? How did this value come up? Is there any specific reason to use 120 ohm?


print("this text is blue")  How could I make the text blue? I have: print('\033[94m' + "this text is blue")  and print("\033[94mthistextisblue")  However, nothing has worked so far.

How can I output colored text to the terminal in Python?


I saw many people having arrest and interrogation transcripts of people arrested in the 1930s in the Soviet Union.  Where can I get such documents? Are they online?

One of my ancestors was arrested and killed in the purges of the 1930's in the Soviet Union. I've heard of people who got papers from the Russian (post Soviet) government containing the "crimes" they were accused of and the interrogation they were subject to,  Where can I find this data? Is it online?


I'm trying to create a function that will echo the previous to last command from the current terminal. This is the expected output (here I call the desired function f):  $ history 1 history 1 $ f history 1     Side question: Where does history(1) saves the current terminal's history. I know that when the terminal session ends history is typically saved in $HISTFILE (which is set to ~/.bash_history in my case). But I'd like to know where history(1) keeps the history of the currently running terminal.

If I run history, I can see my latest executed commands.  But if I do tail -f $HISTFILE or tail -f ~/.bash_history, they do not get listed.  Does the file get locked, is there a temporary location or something similar?


I am experiencing a weird unknown behavior in excel. The sheet I want to export to a csv file consists of 4 columns with data like this:  site.aspx|de|lblChanges.Text|some text that will be used somewhere   Now what happens is, if the last column containg the text has doublequotes in it, Excel adds another double quote to it for every double quote already in it.  Example:  site.aspx|de|lblChanges.Text|some text that will used somewhere here   Gets transformed into  site.aspx|de|lblChanges.Text|"some text that will used somewhere here"   Notice the extra doublequotes at the beginning and the end, which clearly should not be there. this data gets inserted in a database and used as text resources for globalization. If I render a literal control with those extra double quotes the functionality breaks.  How can I supress this behavior in Excel?

I have an Excel file with Unicode content of which some cells contain text inside double quotes, for example "text".   When I save the Excel file to a text file in Unicode format, the text which contains the double quote is saved as three double quotes, for example """text""".  There are some places where I even have text which contains comma (,). For example, text, which is converted into "text," in the Unicode file. It is adding double quotes to the text, which I guess contains special characters.  How can I avoid this?


I used to be able to cd into aliases with my Mac. Today I was messing around with ~/.bashrc and ~/.bash_profile to make PostgreSQL work. After I restarted my computer it stopped cd'ing to aliases and after some research I figured I was not supposed to be able to do that from the beginning.   So I do not know how I was able to cd into aliases before or how I broke it (maybe a system update became valid after restart, I wasn't restarting for a while). I have only found the following answer on couple places .   I am looking for an explanation to what happened and a simple way of fixing it rather than modifying cd function itself. I do not prefer creating a symbolic link because it would be broken when I make a change in the actual file & I have many aliases to replace so it seems like a redundant work.   Note: Im still not able to cd into aliases when I undo the changes I made in ~/.bashrc and ~/.bash_profile, so this seems to be caused by something else or my changes triggered something once and it was enough for a permanent change.

I have two aliases in my home directory: devbootcamp and bookshelf. I can cd into devbootcamp but not bookshelf but I'm not sure why. I don't remember how I made the alias to devbootcamp but I followed  tutorial to create the bookshelf alias. Also strangly in my terminal devbootcamp is purple but bookshelf is not. How do I make it so they have the same functionality?


I'm making a button that will open up a list and change a class type that will change the img.   It is for a overwatch lootbox opener and the button will open up what they have obtained. I want it so the img changes from + to - and that it will show and not show the list of what they got.  Here is the code:  JAVASCRIPT    function itemLog() {   var log = document.getElementById("log")   var btn = document.getElementById("bt")   alert(btn)   alert(log)   if (btn.class == "toggle fa fa-minus-circle") {       btn.class = "toggle fa fa-plus-circle";   }   else {     btn.class = "toggle fa fa-minus-circle";   } } <!DOCTYPE html>   <title>Home |OWLBS</title> <link rel="icon" type="image/png" href="favicon.png"> <link href="css/style.css" rel="stylesheet" type="text/css" /> <link href="css/animate.css" rel="stylesheet" type="text/css"> <link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css" rel="stylesheet" type=text/css> <link href='https://fonts.googleapis.com/css?family=Open+Sans:300,400,500,600,700' rel='stylesheet' type='text/css'> <link href='https://fonts.googleapis.com/css?family=Raleway:400,600,700' rel='stylesheet' type='text/css'>

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How can I change the class of an HTML element in response to an onclick or any other events using JavaScript?


I want to enclose my matrix by a box. I have followed the instructions in this   but couldnt get the borders correct. Here is how the frame looks like and the code.     \begin{frame} \medskip\par\noindent \begin{minipage}{0.4\linewidth} \newcommand*{\WidestText}{ \begin{bmatrix} 1 & 2 & 3 \\[0.3em]\end{bmatrix}.* \begin{bmatrix} 4 \\[0.3em] 2 \\[0.3em] 1 \\[0.3em] \end{bmatrix} =\text{ERROR}  }% \tikzmark{left} {\footnotesize \[ \begin{bmatrix} 1 & 2 & 3 \\[0.3em]\end{bmatrix}.* \begin{bmatrix} 4 \\[0.3em] 2 \\[0.3em] 1 \\[0.3em] \end{bmatrix} =\text{ERROR}  \] } {\footnotesize \[\begin{bmatrix} 1 \\[0.3em] 2 \\[0.3em] 3 \\[0.3em] \end{bmatrix} .* \begin{bmatrix} 4 \\[0.3em] 2 \\[0.3em] 1 \\[0.3em] \end{bmatrix} = \begin{bmatrix} 4 \\[0.3em] 4 \\[0.3em] 3 \\[0.3em] \end{bmatrix} \] } \makebox[\widthof{\WidestText}][l]{  }\tikzmark{right} \DrawBoxWide[thick, brown] \end{minipage} \end{frame}

I'm aware of possibilities to frame an "important" equation in Latex as the one suggested in mathmode for instance but I thought it would be nice to have a dedicated environment instead of putting frames or boxes around equations on the fly. So I came up with what follows by just adapting the existing equation environment:  \documentclass[fleqn,12pt]{book} \usepackage{microtype} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{kpfonts} \usepackage{xcolor} \usepackage{amsmath} \usepackage{framed}  \renewcommand*\FrameCommand{\fcolorbox{red!80}{red!20}}% \makeatletter \newenvironment{fequation}{% %\setlength\abovedisplayskip{3pt} %\setlength\belowdisplayskip{3pt}   \incr@eqnum%   \mathdisplay@push%   \st@rredfalse \global\@eqnswtrue%   \MakeFramed{%   \vspace*{-\baselineskip}%   \FrameRestore}%   \mathdisplay{equation}% }{%   \endmathdisplay{equation}%   \mathdisplay@pop%   \ignorespacesafterend%   \vspace*{-\baselineskip}   \endMakeFramed\noindent% }% \makeatother  \begin{document} Suspendisse lectus tortor, dignissim sit amet, adipiscing nec \begin{equation} \cos t=\pi \end{equation} porttitor, orci nec nonummy molestie, enim est eleifend mi, non \begin{fequation} \cos t=\pi \end{fequation} vitae, consequat in, pretium a, enim. Pellentesque congue. \begin{fequation} \begin{aligned} &\cos t=\pi\\ &\sin t=-\pi \end{aligned} \end{fequation} vitae, consequat in, pretium a, enim. Pellentesque congue. \begin{fequation} \biggl(\int_\Omega \frac{t^2}{t+1}\D{t}\biggr)=1 \end{fequation} \end{document}   I've been playing around the \vspace* as well as \abovedisplayskip and \belowdisplayskip commands for tuning but I am wondering how to control the vertical white space between main text and framed equations? Also, any improvement that you find interesting is welcome.


I was dual booting Ubuntu 18.04 with Windows 10 before. Now after upgrading to Ubuntu 19.04 , my laptop directly boots into ubuntu without grub menu. Also when I checked the bios boot menu there was no windows boot loader. I ran boot-repair by booting into live usb and this is the link it gave me .   I dont think the EFI System is mounted on /boot/efi. In fact I dont even have such a mount point. Could that be the cause of this problem? Any help appreciated.  Edit - This is not a duplicate as in my situation I am unable to locate the windows boot loader in the BIOS

I installed Windows on my computer, followed by an installation of Ubuntu. However, now I'm unable to boot into my Windows install.  What can I do to fix this?


Ok so... My friend and i used to walked to school sometimes but we haven't done that recently. I messaged him " we haven't walked in a while " He replied " for a while* " And now we're arguing over it. Which is correct?  Thanks

I recently got a message that says      Haven't heard anything from you in a while.   I always thought that the right way to say this would be to use for insdead of in. Are both versions correct? Would there be a difference in meaning?


I would like to be able to read the html source of a certain webpage into a string in c# using winforms  how do I do this?

How can I get the HTML source of a given web address in C#?


Hi I came across this question, prove there is no entire function f(z) which verifies that |f(z)| > |z| for every z ∈ C.  I was gonna try use the fact that $g∈C$ such that $f(g)=0$ and maybe that function $1/|f(z)|$ is bounded. Thank you

$f(z)$ is a function such that $|f(z)| > |z|$ for all $z\in\mathbb{C}$  How would you prove the function $\frac{1}{f(z)}$ is bounded. I think you have to use the $|f(z)|\leq M$ but I'm not sure.


I know that there are issues with AMD GPUs on versions 2.9 and above. I recently reinstalled 2.82 and this happens everytime I open a new file. My default cube shows up as what I can only describe as a transparent mesh. In rendered view, there is a black texture which seems to stay static when you adjust the camera angle. I'm very confused as 2.82 worked perfectly for me for over a year. It's really only started having issues since I installed version 2.92 which had a lot of issues and then reverted back to this version. I'm happy to provide more info, but I'm really not sure what info to provide because I'm so confused right now.

I don't know why but now, when i go in material preview or rendered (in solid mode it works fine), my object is entirely gray, or invisible idk, because it has the same color of the background. I've been working for days on this project without having this issue, it suddenly showed up. I tried opening other old projects and suddenly they all do the same so i guess it is some blender program setting that applies for all the projects, but idk how it happened cuz i didn't change anything :/, anyone got any tips?


nathan@gentoodesktop ~/Documents $ mkdir test nathan@gentoodesktop ~/Documents $ mkdir te*/test mkdir: cannot create directory 'te*/test': No such file or directory nathan@gentoodesktop ~/Documents $ cd te* nathan@gentoodesktop ~/Documents/test $ mkdir test nathan@gentoodesktop ~/Documents/test $ ls  test

I am trying to create directory in bulk using mkdir through shell script below is the script  #!bin/bash mkdir /tmp/report*/testfolder*/testdoank   when i run it i got an error  -bash: ./makefolder.sh: bin/bash: bad interpreter: No such file or directory   what is wrong?


Evaluate the sum $1-\frac{1}{2^2}+\frac{1}{3^2}-\frac{1}{4^2}+\frac{1}{5^2}+\ldots$  Been looking for a way to arrive at a solution. Would really appreciate some help here.

I am tasked to evaluate the sum  $$\sum_{n=1}^{\infty}\dfrac{(-1)^{n}}{n^{2}}$$ Using contour integration. This is what I've done so far.   Let $C_{N}$ be the square defined by the lines $x=\pm(N+\tfrac{1}{2})\pi$ and $y=\pm(N+\tfrac{1}{2})\pi$. Let $f=\tfrac{1}{z^{2}\sin(z)}$. I was able to prove that  $$\int_{C_{N}}\dfrac{1}{z^{2}\sin(z)}dz=2\pi i\left[\dfrac{1}{6}+2\sum_{n=1}^{N}\dfrac{(-1)^{n}}{\pi^{2}n^{2}} \right]. $$  By Cauchy's residue theorem. So now if I could prove that he integral converges to zero then I would be done. The problem is that I can't seem to get an upper bound on the integral. I've having trouble with the fact that $|f|$ is unbounded within $C_{N}$ so ML inequality doesn't help me. Any hints would be great. Thanks.


According to my knowledge, we cannot use == operators to compare String values in Java. So I wrote the following code:  public class Test {   public static void main(String[] args) {      String s1 = "My Computer";     String s2 = "My" + " Computer";      System.out.println(s1 == s2);   } }   And I was expecting the result to be false because these are two different objects having assigned different memory locations (please correct me in this regard if I am wrong ). But when I executed the code, the output was true.  Then I changed the value of s2 as:  String str = "My"; String s2 = str + " Computer";      //instead of "My" + " Computer"   And then when I executed the code, the output was false.  Now I cannot understand the difference in these two statements, although I have used + (not the concat() method) in both statements. Can anyone explain, please.

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?


What are all homomorphisms from $\mathbb Z_n$ to $\mathbb Z_n$ ? I know about all automorphisms but am not clear about all homomorphisms ; are there a total of $n$ homomorphisms ? In general , what are all homomorphisms from $\mathbb Z_m$ to $\mathbb Z_n$ ?

This question coutesy of Allan Clark's "Elements of Abstract Algebra" (60$\zeta$).   Find the number of homomorphisms from $\Bbb{Z}_m\to \Bbb{Z}_n$ as a function of $m$ and $n$.  This is stumping me, can anyone help?


I've got a db like this:  Accounts  -------- id BankName AcctNumber Balance  AccountGroups ------------- id GroupName  JoinAccountsGroups ------------------ aid gid   I'm trying to generate data like this:  Bank       AcctNum       Balance    Groups --------|--------------|----------|---------------- Citi       930938        400        Payroll B of A     8372933       100        Monthly, Payroll Wells      09837         800        - Chase      8730923       250        Monthly   Is there an easy way of generating that Groups column in a sql query, that will combine the results of the join into a comma-separated field? I'm currently doing it on the php side using a secondary query on each row as I'm processing it. It's fine for a small dataset, but it seems pretty inefficient...  I'm using php > jet > ms access .mdb file.

I have a table, call it TBL. It has two columns,call them A and B. Now in the query I require one column as A and other column should be a comma seprated list of all B's which are against A in TBL.  e.g. TBL is like this  1   Alpha  2   Beta  1   Gamma  1   Delta  Result of query should be   1   Alpha,Gamma,Delta  2   Beta  This type of thing is very easy to do with cursors in stored procedure. But I am not able to do it through MS Access, because apparently it does not support stored procedures.  Is there a way to run stored procedure in MS access? or is there a way through SQL to run this type of query


I am having a problem with a domain having cached nameservers. It goes to the old website instead of the new in some areas. Am I able to go to the old hosting DNS and change the A record and get it to the new website? How long does this cache take to expire?

I have recently migrated one of my .com-domain zones from DNS provider A to DNS provider B, however the TTL on the NS-records for the zone on provider A is very high = 432000 (5 days), and thus I feel sad thinking that I might have to keep (and potentially update) the zone at the old provider for almost a weeks time.  Question is: Since WHOIS for the domain is already updated with the new nameservers of provider B, can I safely delete the zone at provider A, even though NS-record TTL might not have expired for clients?  Secondary question: What exactly happens when clients contact NS provider A and it doesn't respond with authority anymore? Provider A should just call Provider B and relay a non-authoritative response to the client, right?


I am learning CSS grid. While practicing I got an issue. justify-content: center is not centering  section-3-nav div. Here is my code:   * {     margin: 0;     padding: 0;     box-sizing: border-box;     text-decoration: none;     list-style: none;     font-family: 'Roboto', sans-serif; } .container {     width: 85%;     margin: auto;     padding: 3rem 0; } .container > .constant {     display: grid;     justify-items: center; } .box-top-title > h1 {     font-weight: bold;     margin-top: 2rem; } .box-top-subtitle > p {     text-transform: uppercase;     color: #a8b9c0;     margin: 0.5rem 0;     font-size: 15px; } .box-top-hr > hr {     width: 250px;     background-color: #00c6bf;     border-width: 0;     height: 1.5px; } .section-3 {     background: #eff7fa;     width: 100%; } .section-3 > .container > .section-3-nav {     display: grid;     grid-template-columns: repeat(5, 1fr);     justify-content: center;     margin: 3rem 0;     width: 50%;     border: 1px solid black; } .section-3 > .container > .section-3-nav a {     transition: 0.5s; } .section-3 > .container > .section-3-nav a:hover {     background: #ff3150;     padding: 10px 20px;     border-radius: 15px;     color: white; }

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    Where is the problem with the code? Where to fix and what to fix? It will be very helpful for me if you help to solve the problem. Thank you.

How can I horizontally center a
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The new close/flag dialogs have much smaller draggable title areas. We used to be able to click between the dialog title and the top border in order to move the dialog, now clicking in that area will select text instead. It looks to be about 20px high. If that area at the top of the dialogs could be made draggable again that would be great.

This week we rolled out a series of changes to  of the question close workflow.  You can read more about the details of these changes .    For context, the overall effort to improve the question close experience will be optimized for Stack Overflow. Given Stack Overflow’s scale, many of the pain points we hear about with question closing and reopening are unique to Stack Overflow and won’t make sense for other network sites. However some  changes are general improvements that should improve usability and guidance overall. Wherever possible, we plan to roll these changes out network wide as well. Any time we roll out a change network wide, we’ll make sure to cross-post here. This first phase is being rolled out to the network and is why I’m posting today.  Let us know if you run into any issues or have questions regarding the network here.


I wish to write a pure-text square root symbol, like √. The purpose is to write an instruction as it is displayed on a simple calculator, i.e. something like √(2+3). I am aware of $\sqrt{}$, but I don't want to use this because with an empty argument, the square root-sign is too low compared to the surrounding text. I could fix the position of the symbol using something like $\sqrt{\color{white}{|}}$ (provided I have xcolor loaded) but the result isn't beautiful.  Is there a command to produce the √-symbol (such as we have \$ for $)? Apparently \√ doesn't exist.  Detexify suggests   $\surd$, which is exactly a math-mode square root sign without argument. \textsurd (provided the package textcomp) comes close.   I wonder if there is an exact version of √, i.e. as one can use in other text-editors.

I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?


I work on the command line quite a bit and often have to take a screenshot a region of the screen and save it to directory I am currently working in.  (let's assume I've already taken the screenshot and clipboard has it).  This is how I have to do it right now (after have the screenshot in clipboard):   launch Preview. in Preview, ⌘ + N (File, New from Clipboard) creates a new file with the clipboard contents. go back to command line and copy the directory name (copy the results of pwd) go to Preview, ⌘ + S for Save.  Type / gets me a directory navigation prompt where I can paste my directory name from step 3.   Finally, give the actual file name, this_is_where_I_get_the_error.png in my example.   I'd like to do this instead:  $savemyscreenshot ./this_is_where_I_get_the_error.png  How would I go about writing that savemyscreenshot command?  In bash?  As an Automator script (which has to be callable from the Terminal, else that defeats the purpose somewhat)?  All things being equal, would slightly prefer a javascript flavor of the Automator script over AppleScript.  env:  MacOS Sierra

I have a graphic on the clipboard on OS X.  What's the quickest way to get it onto disk as a png or jpg?


When we push a wall the wall does not move so, no work is done but still we get tired Why? What energy changes occur in this process.

I read the definition of  as  $$W ~=~ \vec{F} \cdot \vec{d}$$  $$\text{ Work  =  (Force) $\cdot$ (Distance)}.$$ If a book is there on the table, no work is done as no distance is covered. If I hold up a book in my hand and my arm is stretched, if no work is being done, where is my energy going?


On our real estate site we are planning to put Spanish text (2-3 lines) at bottom of every page. Except for the bottom part, all the content is in English.  I am new to Page Rank & Google search optimization. So i have few queries related to that:   How this Spanish content will affect rankings? Will it help to search through Spanish words? I mean, if user searches using Spanish words will our pages come in search results?

Because I'm Latin, sometimes I use a word in English while talking in Spanish.   In a website, for example, I could be interested in ranking for a word as “promoter” inside a page in Spanish, because that is how my public understands that concept.  Does the latent semantic indexing (LSI) (or whatever Google uses for semantic relation) fail to relate “promoter” with the content (because there are not related words in English) and then could that prevent my site from ranking?


On most hobby Li-ion packs there is a prominently displayed C rating (typically 20 - 35), which tells you how many amps you can draw from it, in a multiple of the capacity.  I have never seen a C rating on a NiMH pack. Neither do you normally see how many amps you can draw from the battery.  What is a typical C rating for a NiMH battery?  Note: I am looking for an estimate, so if it's a range, go ahead and put that. I do not have a particular battery in mind.  EDIT:  I can see that I was misunderstood already by EM Fields. Let me try to clarify. The C rating refers to a constant with units of 1/hours which gives the peak amp draw in terms of the capacity, like this: Capacity [Ah] x C rating [1/h] = Max draw [A]

Im looking for some official information source about maximum current for Panasonic Eneloop BK-3MCC rechargeable batteries.  All I found is , there is just 1 table (nothing about maximum discharge current), charge and discharge characteristics.  UPDATE LINK:   / edited - I fixed my mistake, I meant 6A not 8A /  There is discharge characteristic for 6000mA discharge. So... I can safely draw 6A from that AA cell?


String can contain anything, but must have one asterisk (*) throughout the string and that asterisk can be anywhere in the string.  Also string should not contain any blank spaces.  Following are valid strings:  test* *_test test*something   Following are invalid strings:  test_** **_test test*something* test *something test * testsomething *   Someone please help me writing a regex for the above scenario.

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


In a gambling game you can win a very huge amount of money if you can get 10 consecutive heads tossing a coin. Each toss costs you 1$. How much money will you bet, on average, in order to get 10 consecutive heads?

A fair coin is tossed repeatedly until 5 consecutive heads occurs.   What is the expected number of coin tosses?


What is the meaning of $2^\sqrt{3}$ ?  one can explain $2^3=2\times2\times2$  But how can I explain $2^\sqrt{3}$ etc. ?  How can I explain non-integer powers? I do not want the value. I need to know whether there is an explanation for this in real analysis.

We all know that $2^5$ means $2\times 2\times 2\times 2\times 2 = 32$, but what does $2^\pi$ mean? How is it possible to calculate that without using a calculator? I am really curious about this, so please let me know what you think.


Find the number of ordered pairs of integers $(x,y)$ satisfying the equation $x^2+6x+y^2=4.$   My attempt:  $x^2+6x+y^2=4$  $x^2+6x+9-9+y^2-4=0$  $(x+3)^2+y^2-13=0$  $(x+3)^2=13-y^2$  $x$ is required to be an integer. Therefore, let us consider $x$ as an integer.  Therefore $(x+3)$ is also an integer. Similarly $y$ is an integer. Now, the square of any integer is a non-negative integer and more specifically a perfect square.   Therefore, $(x+3)^2$ and is a perfect square  $\implies 13-y^2$ is a perfect square  $\implies y=-3,+3,-2,+2$ (By trial and error method)  For $y=-3, +3$, there are two values of $x$ which are $x=-1,-5$  For $y=-2,+2$, there are two values of $x$ which are  $x=0,-6$  Hence there are eight ordered pairs in total: $(-1,-3),(-5,-3),(-1,+3),(-5,+3),(0,-2),(-6,-2),(0,+2),(-6,+2)$.   Therefore the number of ordered pairs of integers satifying the equation $x^2+6x+y^2=4$ is $8$.  My problem:  Is my method correct? Is there any other method to solve this problem?

I need to find the number of ordered pairs of integers $(x,y)$ satisfying this equation:   $$x^2 + 6x + y^2 = 4.$$   I have tried, and I think $x<0 . $  Is there a specific way to solve such equations?


When I'm trying to update all packages in my environment, using GUI or from terminal by : sudo apt-get update  I get :  It simple says : ... Err:19 http://ppa.launchpad.net/beineri/opt-qt-5.11.1-xenial/ubuntu bionic Release   404  Not Found [IP: 91.189.95.85 80] ...  Using the GUI, I get :  But it exists :

When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?


I am new to python and I am trying to iterate through a list and append every 8 lines from a file to a list.  Which I will append to those elements and rewrite this list on a new file.  What I am keep running into is getting specific sections out of the txt file that I want.  Here is my code:  tester1=1 tester2=9 for n,line in enumerate(myList):     if n>(tester1) and n<(tester2):         tempList.append(line)         tester1=tester1+8         tester2=tester2+8   So I do not want line 0,1.  But lines 2 through 8.  Next I need it to go to line 9 through 17... and so on.  This current code is giving me every 8th element in my txt file which was made into a list.

I have a list of arbitrary length, and I need to split it up into equal size chunks and operate on it. There are some obvious ways to do this, like keeping a counter and two lists, and when the second list fills up, add it to the first list and empty the second list for the next round of data, but this is potentially extremely expensive.  I was wondering if anyone had a good solution to this for lists of any length, e.g. using generators.  I was looking for something useful in itertools but I couldn't find anything obviously useful. Might've missed it, though.  Related question:


I am trying to get  my head around, what happens here ? What sort of code does the compiler produce?  public static void vc() {     var listActions = new List<Action>();      foreach (int i in Enumerable.Range(1, 10))     {         listActions.Add(() => Console.WriteLine(i));     }      foreach (Action action in listActions)     {         action();     } }  static void Main(string[] args) {    vc(); }   output:  10 10 ..  10  According to , a new instance of ActionHelper would be created for every iteration. So in that case, I would assume it should print 1..10. Can someone give me some pseudo code of what the compiler is doing here ?  Thanks.

I met an interesting issue about C#. I have code like below.  List<Func<int>> actions = new List<Func<int>>();  int variable = 0; while (variable < 5) {     actions.Add(() => variable * 2);     ++ variable; }  foreach (var act in actions) {     Console.WriteLine(act.Invoke()); }   I expect it to output 0, 2, 4, 6, 8. However, it actually outputs five 10s.  It seems that it is due to all actions referring to one captured variable. As a result, when they get invoked, they all have same output.  Is there a way to work round this limit to have each action instance have its own captured variable?


After updating to Ubuntu 19.10, pressing the Super button only shows the list of the currently opened applications. It does not show the applications list when nothing is opened.  Also, the search bar is missing and I need to search the applications manually from the top bar.  My current Ubuntu version is 20.04 LTS and gnome-shell version is 3.36.1 and the problem still persists.  The image below is what I see on pressing the super button.

I did an upgrade today to the latest version of ubuntu. Everything looked good and fine only for me to discover that I cannot find my applications after clicking the 'Show Applications' icon. The same applies when I search for an application in the search bar, I do not see it. It shows me an endless search.  These are the screenshot images of the problem:      In the meantime, I access my applications from the menu at the top bar and also use the terminal to run applications with CLI.


Consider a number $r$ obtained by:  $r=a \cdot b \mod n$  Can knowing the factorization of $r$ reveal some information (bits) of $a$ and $b$ ?

Consider the case that  $c = a \cdot b \mod p$  where $p$ is a known prime and $0 < a < p$ and $0 < b < p$ are unknown integers numbers. Furthermore, some bits on the value of $c$ are known.  Q1: Can an attacker learn some bits of $a$ using this information?  The question is based on the following non-modular example:  $a = x_1 \cdot 2^z + x_0$   and   $b = x_2 \cdot 2^z + x_3$  gives the product:  $a \cdot b = x_1x_22^{2z} + (x_0x_2+x_1x_3)2^z + x_0x_3$  Then if anyone knows the $z$ least significant bits of $a \cdot b$ (the product $x_0x_3$), then some of the divisors of $x_0x_3$ is equal to $x_0$, allowing to bound the possible values of $x_0$ to the possible divisors of $x_0x_3$.  Q2: Can this non-modular analysis be applied to the modular one ?


Is python confused, or is the programmer?  I've got a lot of lines of this:  some_dict[0x2a] = blah some_dict[0xab] = blah, blah   What I'd like to do is to convert the hex codes into all uppercase to look like this:  some_dict[0x2A] = blah some_dict[0xAB] = blah, blah   So I decided to call in the regular expressions.  Normally, I'd just do this using my editor's regexps (xemacs), but the need to convert to uppercase pushes one into Lisp.  ....ok... how about Python?  So I whip together a short script which doesn't work.  I've condensed the code into this example, which doesn't work either.  It looks to me like Python's regexps are getting confused by the brackets in the code.  Is it me or Python?  import fileinput import sys import re   this = "0x2a" that = "[0x2b]"  for line in [this, that]:     found = re.match("0x([0-9,a-f]{2})", line)      if found:         print("Found: %s" % found.group(0))   (I'm using the () grouping constructs so I don't capitalize the 'x' in '0x'.)  This example only prints the 0x2a value, not the 0x2b.  Is this correct behavior?  I can easily work around this by changing the match expression to:      found = re.match("\[0x([0-9,a-f]{2}\])", line)   but I'm just wondering if someone can give me some insight into what's going on here.  Running Python 2.6.2 on Linux.

What is the difference between the search() and match() functions in the ?  I've read the  (), but I never seem to remember it.  I keep having to look it up and re-learn it.  I'm hoping that someone will answer it clearly with examples so that (perhaps) it will stick in my head.  Or at least I'll have a better place to return with my question and it will take less time to re-learn it.


I was introduced by a spectacles shop about a new technology called computer lens which block blue light that is harmful to eyes. He says it reduces eye-strain for workers who need to be face a computer monitor for hours every day.   More importantly, are there any side effects or harmful effects that one need to be aware about computer lens? I am fine with paying more but not ok if the "gimmick" is harmful to my eyes.

It's very likely that I will be spending most of my life in front of a computer monitor. This is necessary for my profession and the fact that improving technology requires us to look at screens more. My eyesight is near perfect and I never needed any glasses or lenses. However, I notice that all the staring at screens takes a toll on my energy during the day and I want to protect my eyes.  I have already altered the brightness/contrast and colour of my monitor. I also installed  software on my computer.  My question is this: I came across computer glasses but opinions are divided and I wonder what is true. As far as I know there are two types: tinted glasses and glasses with a correction (I'm Dutch and I don't know the perfect translation for glasses with a certain "focus" or "correction". Edits more than welcome) I'm not really interested in the tinted version since I covered that with adjusting the settings of my monitor. My interest is in glasses with a low correction that cancels out or reduce staring. Is it safe to assume that glasses like these will reduce the strain on my eyes because they don't have to focus so much anymore?  As I already said, the opinions are a little divided. One website is positive, another isn't. Even the answers to  say different things. One person recommends special glasses another thinks they're not helpful.


I am looking for a shapefile of the rough outline of the UK to use as a basemap, where is the best place to source one? All the shapefiles I have found have been extremely detailed with internal boundaries etc.

I'm looking for a shapefile for the coastline of the UK.   I'm guessing the Ordnance Survey 'geo-portal' is the best place to get this, but whenever I go to the Ordnance Survey site I get the shakes. (Seriously, trying to find any data on that site is really traumatic. I don't have a spare three days.)  Does anyone just have a simple URL for such a shapefile?


I need to create a random string of letters, but have never used the random class before.   here is the spec: Create a small program that will ask the user to enter their name. Store the name in a string Print the name Ask the user to change their last name Manipulate the string to the new last name. Print the new name. Create an infinite loop that will change the string variable randomly.  See if your program will crash.  so far I have this  import java.util.Scanner; import java.util.Random;  public class StringNames {      public static void main(String[] args) {          System.out.println("Please enter a name");          Scanner myInput = new Scanner(System.in);         String firstName = new String();         firstName = myInput.next();          String lastName = new String();         lastName = myInput.next();          System.out.println(firstName + " " + lastName);          System.out.println("Please change your last name");         lastName = myInput.next();          System.out.println(firstName + " " + lastName);          for (;;) {          }     }  }   How can I create a random string of letters to change the last name to in the infinite loop? I am unsure how long the string has to be. The simpler the code the better. I am slow.  Thank you for your guidance

I've been looking for a simple Java algorithm to generate a pseudo-random alpha-numeric string.  In my situation it would be used as a unique session/key identifier that would "likely" be unique over 500K+ generation (my needs don't really require anything much more sophisticated).    Ideally, I would be able to specify a length depending on my uniqueness needs. For example, a generated string of length 12 might look something like "AEYGF7K0DM1X".


In the FIFO design, to compare the rptr and wptr, we are feeding one signal into another clock domain. The rptr which is coming from the slow clock domain to faster one can be synchronized with sync Flip-flop logic explained in the beginning. However, the wptr which is coming from fast clock domain to slower clock domain and it cannot be synchronized. For example, If Write clock faster 10 times than Read Clock, then sync_w2r doesn't sample the wptr which is based on wclk.  AS you can see the above waveform, din[10:0] on the write(fast) clock is sampled by read clk clock(slow). and the din is a write pointer which is encoded by Gray. and dout[10:0] is a signal synchronized signal by read clock(slow) Actually Gray Encoded pointer signal(dout[10:0]) looks not having a continuously sampled by read clock. you can see the dout[10:0]. It causes a race condition problem. Even Gray encoded signal is synchronized by 2 stage flip-flops. but gray encoded signal does not work to avoid race condition issue at the each of edge sample clock. 1(sampled)-3-2-6(sampled)..go on.. it's actually 2 bits signals were changed from 2'b001 to 2'b110. how can we explain the Gray encoded signal can be used to avoid a race-condition problem? How is the problem solved?

I'm trying to understand how clock crossing FIFOs are implemented, and the usual answer I see to convert the read/write address pointers to gray code and then pass through synchronizer circuits into each others clock domain to determine if there's data in contained in the FIFO. The idea of using gray code is so the other clock domain can detect metastability on the other end by the fact that only one bit should change per address increment...and it can safely ignore the address pointer until it looks valid.  What about the scenario where the write clock domain is much faster than the slow clock domain? If the write address pointer can increment many times per read clock cycle, at some point there will be more than 1 bit flipped in the gray code value, and that wouldn't necessarily be a mistake. How is this situation usually handled?  I know there's a similar question on SE, but the answer seems to show an example of the write clock being only 2x faster than the read clock, so maybe this situation is never experienced.


On Ubuntu when changing sound volume with keyboard it increasing or decreasing too much for me (something like 5% or 10%).  I wanted to change the volume with 1% every time keyboard button is pressed.   So I assigned custom shortcuts for a command amixer -D pulse sset Master 1%+   But now, when I use those buttons I don't see a box notifying about the current sound level. How do I invoke it?

When I press the volume up/down keys on my keyboard, the volume changes too much. How can I make the step size smaller so that I have finer control?


first of all i want to say that i TRIED EVERYTHING I WAS ABLE TO FIND ON INTERNET ( literally every question on forum ubuntu and askubuntu but wifi is still weak  information:   4.15.0-45-generic ( ubuntu fresh install ) hp computer secure boot disable   EDIT : SOLVED INSTALLING UBUNTU 18.10  i've tried to git clone  and install it; select the antenna and check wifi strength ( nothing change )  what else can i do?

I have the Realtek rtl8723be driver on my HP-Pavillion Notebook.  While installing Ubuntu 18.04 LTS through plug-n-play option, I tried the following commands before actual installation:  sudo modprobe -r rtl8723be sudo modprobe rtl8723be ant_sel=2   and the wifi was working just fine.  But after installation alongside Windows 10, somehow the wifi stopped working properly, and now only wifi networks very close to the device appear.  I tried installing realtek software from  as mentioned in the README. But still no progress.   I even tried changing ant_sel parameters, then saving them to my /etc/modprobe.d/rtl8723be.conf and then performing a cold boot. But still no progress.  I also tried installing from , but I got errors.  sudo lshw -class network   *-network                         description: Wireless interface        product: RTL8723BE PCIe Wireless Network Adapter        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:08:00.0        logical name: wlo1        version: 00        serial: 70:77:81:bf:a7:b9        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless        configuration: broadcast=yes driver=rtl8723be driverversion=4.15.0-36-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11        resources: irq:18 ioport:5000(size=256) memory:c6100000-c6103fff   *-network        description: Ethernet interface        product: RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:09:00.0        logical name: eno1        version: 0a        serial: 3c:a8:2a:ba:12:6f        size: 10Mbit/s        capacity: 100Mbit/s        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation        configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8107e-2_0.0.2 02/26/15 latency=0 link=no multicast=yes port=MII speed=10Mbit/s        resources: irq:19 ioport:4000(size=256) memory:c6004000-c6004fff memory:c6000000-c6003fff   *-network        description: Ethernet interface        physical id: 3        logical name: enp0s20u2        serial: ea:f8:17:e8:82:30        capabilities: ethernet physical        configuration: broadcast=yes driver=rndis_host driverversion=22-Aug-2005 firmware=RNDIS device ip=192.168.42.6 link=yes multicast=yes   Can anyone suggest what to do now?


I'm looking for deep knowledge for running Visual Studio IDE in Ubuntu. Can anyone tell me what were the requirements to do so. Ofcourse wine is a process available but as It themselves says vs2019 run garbage. So is there's a way ??? Also mono is available but it's not supported latest .net framework and lots of missing features. They develop it already for prev framework but why not for latest framework?

Why are packages in the official Ubuntu repositories older than the latest (upstream) versions from Debian Sid, PPAs, the authors, etc.?


Is there a way to get a notification that a thread no longer runs (has returned) in your application? I know this is possible in kernel mode (using PsSetCreateThreadNotifyRoutine), but is there a way to know this from user mode, using only Win32 API ?     The problem is that I can't control the code in the thread, because my module is part of a library. Making a driver to monitor the system would not be too hard, but it's annoying for the users to install a driver even for a basic application that uses my library.    My code uses TLS storage, and under Linux/Unix pthread_key_create can take a pointer to a function that is called when the thread is destroyed. But TlsAlloc (Windows) has nothing like this...  Thanks in advance!

How can I determine if a Win32 thread has terminated?  The documentation for  warns to not to use it for this reason since the error code STILL_ACTIVE can be returned for other reasons.  Thanks for the help! :)


Microsoft Paint is the worst image editing tool I could ever imagine of, but it has one good thing that still makes me use it over Photoshop: When I enlarge a small, pixelated 16x16 image, it doesn't make it blurry, instead, it enlarges every pixel in the image, so that the image will still look pixelated as it did before, but now it's just bigger.  I know that this by itself might not be the best resizing algorithm and in most situation's, Photoshop's way of doing this proves to be more satisfactory. However, I'm doing some pixel art right now and I need the pixels to still look like squares when I enlarge the image. I would just use Paint, but the problem with Paint is that it doesn't keep transparency.  In a nutshell, the question is: How to enlarge an image in Photoshop without making it blurry, like the way Paint does? In other words, "Enlarge as if I've just zoomed in."

I design emoticons, and often I need to resize things. However, this usually needs to be done without anti-aliasing. I can't find anywhere to do this.  It's kind of backward, as it's actually harder for a program to use anti-aliasing than not. It also means I need to spend lots of time hand-pixelling everything twice as large.  I'd especially prefer a way that this can be done within Photoshop CS3, though it's not required.


I want to import some data from a json file (which contains a json array of objects) into mongodb using mongoose. When the route '/import' is called I load the file via "require" and start iterating.  router.get('/import', function (req, res) {   var data = require('../import/1.json');   nTotal = data.length;   for (var i = 0; i < nAppCount; i++) {     var obj = new MyObject(data[i]);     obj.save(check);   } });   Since JSHint warns me not to "make functions inside a loop", I created my function called check as follows:  function check (err,doc){   nProcessed++;   if (err) {     logger.log('error', err.message, err.errors);   } else {     logger.log('debug', "%d of %d processed",nProcessed, nTotal);     if (nProcessed===nTotal) {       res.render('index');     }   } }   Everything works as expected until the end but when all objects are processed I get:     ReferenceError: res is not defined   Isn't "check" supposed to "know" res variable being a closure function? How am I going to access "res"?  Note: I can make it work if I ignore jsHint warning.

How would you explain JavaScript closures to someone with a knowledge of the concepts they consist of (for example functions, variables and the like), but does not understand closures themselves?  I have seen  given on Wikipedia, but unfortunately it did not help.


I'd like to be able to install packages for PyMOL like  and to do so I understand I need to know where it is installed (i.e., the file directory). I installed it using Ubuntu Software Centre.

Since I have not been able to open Dash Home in 12.04.4 see , I am hoping for a work-around. Is there another convenient way to open apps/programs without having to search through folders? Is this question clear enough? For example, I just installed Kile (publishing program) from the Software Center, but I can't find a link/tile/icon/shortcut to open it. Thanks, to whomever can help.


I'm currently working on a minimal report building tool. My idea is that the admin is able to build a small form within the frontend. Everything within the white card body is to be displayed, the other table at the bottom is just visible for debugging. the idea itself: the user clicks on one of the dashed bordered buttons at the top and the code copies the coresponding tr from the table below to the main table. so for example, copying the Textbox the tr from below and appends that to the above table. This is working already as planned. The issue: I have a delete button as well, so whenever the user clicks on the delete button in the upper table, it's suppost to delete the table row within the button. here's the code I'm working with: <script>     $(document).ready(function(){         $('.addReportElement').on('click', function(){               let selected = this.id.replace('copy', '');              var row = $('#copy' + selected).closest('tr').html();             $('#tableberichte tbody').append('<tr>'+row+'</tr>');              /* ... */          });          $('.removeTableRow').on('click', function(){             $(this).parents('tr').remove();         });     }); </script>  I don't understand, why it's not deleting one of the copied tr elements, but deletes the ones in the second table.

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


All positive and negative numbers including zero are called integers. So in the form $a=bq$, since $0 = 0ㆍq$ is true for any integer $q$, $0$ can have $0$ as a divisor of itself as well as a multiple of itself by the definition expressed by $a=bq$.   But why it's said "We cannot divide by $0$"? It's understood as "$0$ cannot be a divisor" to me.  "Definition: An integer a is called a multiple of an integer $b$ if $a=bq$ for some integer $q$. In this case we also say that b is a divisor of $a$, and we use the notation $b | a$ . . . On the other hand, for any integer $a$, we have $0 = aㆍ0$ and thus $0$ is a multiple of any integer."   Source: Abstract Algebra: Third Edition, John A. Beachy, William D. Blair, p.4.  "Rule Division by $0$ is undefined. Any expression with a divisor of $0$ is undefined. We cannot divide by $0$"   Source: Prealgebra: A Text/Workbook, Charles McKeague, p.61.  "Observe that division by the integer $0$ is not defined, since for $n≠0$ there is no integer $x$ such that $0ㆍx=n$ and since for $n =0$ every integer $x$ satisfies $0ㆍx=0$"   Source: Introduction to Mathematical Proofs, Second Edition, Charles Roberts, p.99.  [Now I understand my question more after reading number theory chapter of a book]  $0=d\cdot 0 $ Thus, 0 is a multiple of every integer except 0.

I came up some definitions I have sort of difficulty to distinguish. In parentheses are my questions.   $\dfrac {x}{0}$ is Impossible (  If it's impossible it can't have neither infinite solutions or even one. Nevertheless, both $1.$ and $2.$ are divided by zero, but only $2. $ has infinite solutions so as $1.$ has none solution, how and why ?) $\dfrac {0}{0}$ is Undefined and has infinite solutions. (How come one be Undefined and yet has infinite solutions ?) $\dfrac {0}{x}$ and $x \ne 0$, it's okay for me, no problem, but if someone else wants to add something about it, feel free to do it.


My code: enum class list{one, two}; template <list T> class Base; template <> class Base <list::one>{     A a{list::one};     B b{list::one};     C c{list::one}; }; template <> class Base <list::two>{     B b{list::two};     C c{list::two};     D d{list::two}; };  But I would like to avoid duplicating code, and use reference to specialization value, like this: template <> class Base <list::one>{     A a{T};     B b{T};     C c{T}; }; template <> class Base <list::two>{     B b{T};     C c{T};     D d{T}; };  I can make sludge temporary variable, but does not look good too: template <> class Base <list::one>{     list T = list::one;     A a{T};     B b{T};     C c{T}; };  Is there are any way to get reference to template specialization value?

Although I'm doubtful, I'm curious as to whether it's possible to extract primitive-type template parameters from an existing type, perhaps using RTTI.  For example:  typedef std::bitset<16> WordSet;   Would it be possible to extract the number 16 in the above code without hard-coding it elsewhere? Compiler specific implementations are welcome, though I'm particularly interested in g++.


I know how effective ReLU are for deep neural networks, however i wanted to know if they can be used for smaller networks as well ? ( like a network with 2 hidden layers and 15 units each ).

I am currently working on training a 5-layer neural network, and I got some problems with tanh layer and would like to try ReLU layer.  But I found that it becomes even worse for ReLU layer.  I am wondering if it is due to that I did not find the best parameters or simply because ReLU is only good for deep networks?  Thanks!


Since I'm having performance problems with rsnapshot, I'd like to identify directories with great number of files recursively. I think the problem is not the size of the files, but the file count in particular subdirectories, because the generations (daily.0, daily.1, ...) are not volatile and only have few changes compared to the total number of files.  Unix command du would be exactly what I want, if it returned only the file count and not the sum of file sizes.  I already have a  of all direct subdirectories (recursing into subdirectories), but it's cumbersome to use, because I have to dig deeper and deeper and always have to wait.  Found also a , but not summing up file count of subdirectories. It shows only the number of files in this directory, not from its children.  Doesn't have to be a shell script - I'm open to other scripting languages like Ruby, Python, Perl, JavaScript, ...  Example:  dir1/    file1    subdir1/        file2, file3, file4, file5    subdir2/        file6, file7, file8        subdir3/            file9 dir2/     fileA, fileB   Desired output (listing subdirectories and sum up to top):  4   dir1/subdir1 1   dir1/subdir2/subdir3 4   dir1/subdir2 9   dir1/ 2   dir2/   What I don't want (only listing totals):  9   dir1/ 2   dir2/   and not (only listing file count of . directory):  4   dir1/subdir1 1   dir1/subdir2/subdir3 3   dir1/subdir2 1   dir1/ 2   dir2/

My root filesystem is running out of inodes.  If this were an issue of disk space, I'd use du -s to get a top-level overview of where the space is going, then head down the directory tree to find particular offenders.  Is there an equivalent option for inodes?   will point out individual directories with high usage, but in my case, that's no good: the Linux source directory, for example, gets scattered across 3000+ directories with low inode counts, rather than showing up as /usr/src/linux-4.0.5 52183.


How does GLM source code analyze data, and when we do not know what kind of data exactly belongs to, how to select the best family to fit and get the best result

I have fish density data that I am trying to compare between several different collection techniques, the data has lots of zeros, and the histogram looks vaugley appropriate for a poisson distribution except that, as densities, it is not integer data. I am relatively new to GLMs and have spent the last several days looking online for how to tell which distribution to use but have failed utterly in finding any resources that help make this decision. A sample histogram of the data looks like the following:   I have no idea how to go about deciding on the appropriate family to use for the GLM. If anyone has any advice or could give me a resource I should check out, that would be fantastic.


I have set the title of my website in yoast as shown below in the screenshot.  But on SERP, different title shows up as shown below in the screenshot.  How do I correct this?

I'm just wondering how it is possible that IGN.com has this in its title tag:      Video Games, Cheats, Walkthroughs, Game Trailers, Reviews, News, Previews & Videos at IGN   while on Google its title is simply "IGN".   How can one achieve such a thing? Does it use some special meta tag I can't see?


Is it correct to say "The development team are seeing a new trend", when you're certain that the team consists of several members? Or, is the word team strictly singular in any context?

I'd say Microsoft have a way of bending the rules and I know that McLaren have won the championship. While this sounds strange, I believe it is correct English (sorry, I'm not native).   But when it's a small company, would you still use it this way? Is a company always plural, or are small companies singular? I.e., would you say Bakery Johnson makes fine bread or Bakery Johnson make fine bread? Is it My book seller, Woody's, have moved or is it has moved?


I'm having difficulty proving $n! > n^2$ for $n \ge 4$ I have previously solved a similar problem but it is $n! > 2^n$. Now I don't know how to solve this. I have only come as far as solving for the base case. Thank you so much for helping a struggling student out.

How can I show that $n^2<n!$ for all $n\geq 4$ Step 1 For $n=1$, the LHS=$4^2=16$ and RHS=$4!=24$. So LHS$<$ RHS. Step 2 Suppose the result be true for $n=k$  i.e., $k^2<k!$ Step 3 For $n=k+1$ $(k+1)^2=k^2+2k+1$ What will be the next step?


I want to make a grid around all my points, convert to a polygon and use this to clip the extent of my data. I am using Arc 10.2.  How do I make a grid and then convert it to a polygon? Or is there a way to miss some of these steps?

We are doing the research about applying remote sensed data on hydro logical model . After delineating, the river basin from DEM data using Argis9.3, We have to map the remote sensed data derived from products like PERSIANN. Our task now is to create the grid with the same resolution with the available remote sensed data( for example 0.25degree x 0.25 degree). and have a certain corner that matches with the obtained data.   Does anyone know how to deal with our problem?


In the Harry Potter series, why can't Harry see the thestrals the first time he encounters the carriages? He obviously saw his mother die when he was a child, but until he saw Cedric die, he could not see the thestrals.

Why couldn't Harry see Thestrals at the end of Goblet of Fire after the senseless and shocking death of Cedric Diggory?   At the end of Goblet of Fire, the carriages still appeared horseless to Harry:     Hermione turned away, smiling at the horseless carriages which were now trundling towards them up the drive, as Krum, looking surprised, but gratified, signed a fragment of   parchment for Ron.   Goblet of Fire - Page 629 - British Hardcover - Adult Edition   At the beginning of Order of the Phoenix, Harry sees the Thestrals for the first time:     Here stood the hundred or so horseless stagecoaches that always took the students above first year up to the castle. Harry glanced quickly at them, turned away to keep a lookout for Ron and Hermione, then did a double-take.   The coaches were no longer horseless. There were creatures standing between the carriage shafts.   Order of the Phoenix - Page 178 - British Hardcover - Adult Edition   We know that only those who have seen death can see Thestrals:     ‘Don’ worry, it won’ hurt yeh,’ said Hagrid patiently. ‘Righ’, now, who can tell me why some o’ yeh can see ’em an’ some can’t?’   Hermione raised her hand.   ‘Go on then,’ said Hagrid, beaming at her.   ‘The only people who can see Thestrals,’ she said, ‘are people who have seen death.’   ‘Tha’s exactly right,’ said Hagrid solemnly [...]   Order of the Phoenix - Page 394 - British Hardcover - Adult Edition   A month went by between Cedric's death and the end of the spring term -- is this enough time for Harry to have truly internalized Cedric's death? Goblet of Fire indicates that Harry was in shock following Cedric's murder, but was able to relate the story of Cedric's death to Mr. and Mrs. Diggory.     When he looked back, even a month later, Harry found he had few memories of the following days. It was as though he had been through too much to take in any more. The recollections he did have were very painful. The worst, perhaps, was the meeting with the Diggorys that took place the following morning.   [...]   ‘He suffered very little, then,’ she said, when Harry had told her how Cedric had died.'   Goblet of Fire - Page 621 - British Hardcover - Adult Edition   So, then, why couldn't Harry see Thestrals at the end of Goblet of Fire?


If $x \sqrt{1+y}+y \sqrt{1+x}=0$, prove that $(1+x^2)\frac{dy}{dx}+1=0.$   The answer I got is $$\frac{dy}{dx}= -\frac{2 \sqrt{1+x} \sqrt{1+y}+y}{x+2 \sqrt{1+x}\sqrt{1+y}}$$ but I cannot simplify it further. Please provide your assistance.

Find $\frac{dy}{dx}$ if $x\sqrt{1+y}+y\sqrt{1+x}=0$ for $-1\leq x\leq 1$   My Attempt $$ x\sqrt{1+y}=-y\sqrt{1+x}\implies x^2(1+y)=y^2(1+x)\implies x^2+x^2y=y^2+xy^2\\ 2x+2xy+x^2\frac{dy}{dx}=2y\frac{dy}{dx}+y^2+2xy\frac{dy}{dx}\\ \frac{dy}{dx}\Big[ x^2-2y-2xy \Big]=y^2-2x-2xy\\ \frac{dy}{dx}=\frac{y^2-2x-2xy}{x^2-2y-2xy} $$ How do I proceed further and find the derivative ?


I don't mean to be unhelpful, but I don't sit around waiting for new questions to come in so I can hopefully answer them faster and more thoroughly than everyone else on the internet. I've tried this and failed miserably.  However, by simply being able to upvote other correct answers each time I find something that works for me, I feel like I could contribute to the community without committing too much time.   Moreover, by being able to comment on other people's questions, I feel like I could help describe my own experience solving similar problems in ways that can be helpful without having to post my own 95% redundant answer.  Basically, I feel like I'm being punished for NOT asking any questions (see here: ), which I haven't had to do because I've been so successful at finding answers to similar questions on S.O., and therefore I'm stuck with my 1 reputation and no easy way to contribute to the site.  UPDATE - This guy and I have the same problem, so I guess I'm actually hurting the site by posting a duplicate question. Great.

I think more reputation points should be required to add a new answer than to upvote an existing answer.  I don't continually watch for new questions, so usually when I find a question it has already been answered.  It seems bit inappropriate to answer an already-answered question in order to contribute to the conversation, but until you earn reputation, you can't upvote or comment; you can only add new answers, which prevents me from contributing at the moment as much as I would like to.  This seems backwards to me. If someone incorrectly upvotes a bad answer, the damage is minimal, as other users can down vote it and upvote the correct answers. On the other hand, an incorrect answer wastes the time of everyone who reads it.  So, IMHO, it should require more reputation points to add an answer than to upvote or comment on an existing answer.  I wouldn't say say that users should be prevented from answering unanswered questions until they have x reputation points, as that might prevent users who have answers from providing them, but perhaps it should be required if the question is already answered, to discourage users from reiterating previously given answers.  What do you think?


I am travelling from India to NY in coming month.  My flight will halt for about 1 hr at Brussels, for technical checking and passenger on boarding. May I know whether I would require transit Visa-on-arrival at Brussels Airport, if for any unexpected reason passengers are asked to disembark the flight?    I am an Indian citizen.  US Visa type: F1 (Student)

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


Tell me please if it correct different or differently in the following sentence.     But eggs can taste different/differently depending on how fresh they are, the way they're cooked and the diet of the hen.   This passage is from this  and the author uses the word different there. Tell me please why.

I find "think bright" is much more common usage, but why? In my opinion, "Think" is a verb, so it is reasonable to use adverb to describe it.  Examples:      THINK BRIGHT!      The National University of Science and Technology MISIS   ()


I'm designing this animal-type creature, and want to add a transparent .png image to its face with the face features (object has a subsurf). On the left is the image with the features, on the right is the part of the object where I want it to be.    I tried to import the image as a plane, but matching the shape of the plane with the face didn't work, and the lines of the face left shadows on the head, and could be seen as a different object from some angles (although it's the closest I've gotten yet). It looked like this:    So , I tried selecting the faces of the head that the features should go over, and create a new material for it. Unfortunately, since the .png is transparent, the result produced was this:    (where it's impossible to tell the transparency from a black background default color, and where I wouldn't know where to start to adjust size and position).  I also tried UV mapping, but then the whole object became black with the features repeated all over.   Is it something I have to go into Nodes for? I'm kind of stuck here. Creating a new material and applying it is simple, but applying a material that is an image is a bit more complex it seems... Ideally, I would reproduce the same technique for the adhesive bandage on its arm (seen on the right of image 1).

I am trying to create a low poly face with a face from a .png file. The issue is I already have material placed for hair and skin, as shown in the picture below.   I have created a .png file with a face which I would like to overlay over the skin material on the front of the head.    All examples I searched so far assume I also want the color of the material from the .png texture.  Update:  I added UVMapping, changed view to texture, made sure one face is on the eye but nothing is displayed..... see image... I don't know what is going on.


I have two identical machines running ubuntu 15.04. I want to stream audio from one machine to the other.  I have followed this thread to setup my client and server.   The problem is that the server is not discovered and doesnt show up in sound settings.  Suggestions?

Results  I want to be able to walk from one room to another and hear the same song playing. Like you do if you were listening to the radio in all rooms.  I want that effect but I want to listen to my own music, can this be done?  Materials   Ubuntu laptop. Mac computer.   First alternative   I have found and setup the software according to   All of the softwares in both computers and server is setup how should I continue?


If i book a flight that goes for example  London -> Paris -> New York  Is that ok if I miss the London -> Paris flight but get in from Paris? and on return I skip the Paris -> London flight.  I thought it should not be a problem but I remember reading somewhere that airlines do not allow that. Is that true?

Recently I booked a flight using my points. I am  planning to fly to Seattle WA from Indianapolis Indiana.  Stop over is Chicago.  On the day of my flight I am supposed to be in Chicago.   So I was wondering if I can directly board my Seattle flight from Chicago thereby not showing up in Indianapolis.  Is this okay?  Will United airlines cancel my entire journey if I do not show up in Indianapolis?


n = ceil(1234 / (double)1); cout << n << endl;   Here output is 1234 but if I write n = ceil(99999999999999999 / (double)1); cout << n << endl;  This time I get 100000000000000000 as output. Why this happen?

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


When clicking the dropdown arrow for a message in chat, you get the following menu:    If you click the dropdown for a message on the star board, you get this instead:    I'd like the option to reply in the dropdown to a message on the star board. At the moment, the fastest way to reply is to open the message transcript in another tab and use the menu dropdown there. That, or scroll all the way up to wherever the message was in chat.  Another note: messages on the star board always have a link to "history", even if they haven't been edited, whereas other messages don't. Why aren't these menus consistent?

I've run into this a few times; I'll rejoin chat after being away for a while and notice something interesting in the starred section.  I'd like to reply directly to the message but there's no reply button.  Currently, the only ways to explicitly reply to one of those messages are either:-   find the message by scrolling up and looking for it, then click the reply button or; copy and paste the permalink, deleting all the way up to the fragment identifier and adding the colon at the start.   Please add a reply link, even if it just goes in the popup menu it's an improvement.


I know exactly when I read this story, in the spring of 1968, when I was in Germany to improve my german. Of course it could have been written any time before.  I actually read it in german. But I was not really so fluent in german, so I deliberately chose to read this rather short book with the rationale that, being a translation from english, it would have shorter sentences. And it worked, I managed to read it to the end.  I'm almost sure there was only this story in the book, but it was a short one, not a novel, just a novella and not a very long one at that. In hindsight, I would say it was for "Young Adult", but of course I was a young adult then.  The beginning was perhaps inspired by Asimov's "Pebble In the Sky". There was an incident in a nuclear power plant, and a whole community (not a big city, but a town, not too small) was sent into the future. But the Earth they reach is empty. I think the power plant came with them, because I think they still have electric power. That's how they realise that noone else is there because they don't receive any broadcast from anywhere. They use their own radio station to contact other towns or cities but get no immediate answer. But after a few days one spaceship, or maybe more, land near them. Their calls for help have been heard. Out of the spaceship came all kind of species, many alien ones, but also humans. The humans are dominant but the others are not slaves or anything, just like "junior partners". At first the people from the past are very afraid of the strange-looking aliens, but soon find them more friendly than the humans of the future.  Another common point with "Pebble In the Sky" is that these humans from space are not very warm for the Earthlings from the past. The reader at some point finds out that in the past, the humans that left Earth to become "Spacers" despised the ones who stayed on Earth. There was some bitter happenings. And mankind died on Earth. Even though these people from the past were before space travel and thus ancestors to all humans, the spacer humans from the future despise them.  Sure, they came to help, not to kill, but it appears that they want to keep them from modern technology, just help them to barely survive on the empty planet. It is the other species from space who join with the humans from the past. I don't remember any fight or bloodshed. It is just a matter of groups of influence, the spacer humans from the future finding everyone else against them and having to give in and give equal status to all.  Well, this is if I remember the end correctly. The elements which are really remember is the aliens and the humans form the past joining forces against the humans from space. I don't remember violence, but maybe I am wrong.

It starts with a town that was hit by a mysterious explosion which transports that town into a desert. The weather is cold and people burn coal but they soon run out and send out an expedition to look for signs of life - they navigate the desert for a couple of days and come across a glass dome covering a city. Apparently they have been transported far in the future.  And that's where I stopped reading and want to resume now. Don't remember the title or the author and it's at least 20 years old.


I'm using Ubuntu 16.04.6.  I noticed yesterday the Dropbox automation stopped working.  I am now getting the following error message:  Unable to connect to Upstart: Failed to connect to socket/com/ubuntu/upstart: Connection Refused  Does anybody know why this would happen and how I can fix it?

I'm using Ubuntu 15.04. Whenever I tried to install any package, I got the error message in the title. How can I get rid of this annoying error message?  :~$ uname -a Linux LongerVision001 3.19.0-25-generic #26-Ubuntu SMP Fri Jul 24 21:17:31 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux   :~$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 15.04 Release:        15.04 Codename:       vivid   Calculating upgrade... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] y Setting up runit (2.1.2-3ubuntu1) ... start: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused dpkg: error processing package runit (--configure):  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  runit E: Sub-process /usr/bin/dpkg returned an error code (1)


Using below codes makes a table with one column as:  1 2 3 4 5 6 7  CREATE TABLE abc (a VARCHAR(8)); INSERT INTO abc VALUES(1),(2),(3),(4),(5),(6),(7)   But how we can use a method with using (1),(2),(3),(4),(5),(6),(7) , I mean something like 1:7 only?

I need to do a join with a table/result-set/whatever that has the integers n to m inclusive. Is there a trivial way to get that without just building the table?  (BTW what would that type of construct be called, a "Meta query"?)  m-n is bounded to something reasonable ( < 1000's)


I have submitted my application and done the biometrics on March 22. I have my interview on April 3. But I need my original passport before April 9, 2018 as I need to travel to Dubai on April 11, 2018.  I have attached a request letter and also the travel ticket to Dubai as proof so that they process my visa in priority and get it before April 9, 2018.  I want to know whether I will receive my visa and the passport before April 9, 2018 after that interview on April 3, so that I am able to travel to Dubai on April 11.  Thank you in advance.

I think some body here would help me out of this first-time-travelling-blues.  I have applied for Schengen Visa to travel to Greece for four days; I applied to VFS Mumbai, on 13th April, 2016. I have tickets to Greece on 30th April, 2016 and return on 6th May, 2016. I have booked hotels there and am going to attend a scientific conference scheduled for the first week of May, 2016. I was informed during biometric process that as I am travelling abroad for the first time, I may need to attend an interview, scheduled at 22nd April. Now, I am worried, because the date is just 8 days ahead of my departure.   Will I get the visa in time?


$$\lim_{n\to \infty}\frac1{2n}\log\left({2n \choose n}\right)$$  Now, $\log(n!) = \Theta (n\log(n))$ so I think we could write,   $$\lim_{n\to\infty}\frac{1}{2n}\left(\log\left(2n!\right) - \log\left(n!^2\right)\right) = \frac{1}{2n}\left(\log\left(2n!\right) - 2\log\left(n!\right)\right) $$  $$\lim_{n\to\infty}\frac{1}{2n}\left(2n\log\left(2n\right) - 2n\log\left(n\right)\right) $$  $$\log\left(2n\right) - \log\left(n\right) = \log(2)$$  Is this legitimate? I feel this might be wrong since, the $\Theta$ notation conceals a constant factor.

$\lim_{n\to \infty} \frac{1}{2n} \log{2n\choose n}$    I could not approach it beyond these simple steps,    $\lim_{n\to \infty} \frac{1}{2n} \log(\frac{2n!}{(n!)^2})$ $=\lim_{n\to \infty} \frac{1}{2n} [\log(2n)+\cdots +\log(n+1)-\log(n)-\cdots-\log1]$ $=\lim_{n\to \infty} (\log(2n)^{1/2n}+\cdots+\log(n+1)^{1/2n}-\log(n)^{1/2n}-\cdots-\log1^{1/2n})$    Now,I understand that I have to create a sum of limit and produce an integration or use the formula $\lim_{n\to \infty} \log(1+\frac1x)^x=e$ but I cannot do it. Please help!


I am trying to install a SSL certificat on my Ubuntu 14 server (using apache 2). For some reason the port 443 appears to be closed   I installed and enable ssl   /etc/apache2/ports.conf is as followed:  Listen 80  #<IfModule ssl_module> #       Listen 443 #</IfModule>  <IfModule mod_ssl.c>     Listen 443     NameVirtualHost 11.11.11.11:443 </IfModule>  <IfModule mod_gnutls.c>         Listen 443 </IfModule>   LISTEN   root@server01:/home/admin# netstat -ntlp | grep LISTEN tcp        0      0 127.0.0.1:10024         0.0.0.0:*               LISTEN      1317/amavisd-new (m tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      1184/mysqld      tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1116/sshd        tcp6       0      0 :::80                   :::*                    LISTEN      2037/apache2     tcp6       0      0 :::22                   :::*                    LISTEN      1116/sshd        tcp6       0      0 :::443                  :::*                    LISTEN      2037/apache2    UFW  root@server01:/home/admin# ufw status verbose Status: active Logging: on (low) Default: deny (incoming), allow (outgoing), disabled (routed) New profiles: skip  To                         Action      From --                         ------      ---- 22                         ALLOW IN    Anywhere 22/tcp                     ALLOW IN    Anywhere 80/tcp                     ALLOW IN    Anywhere 21/tcp                     ALLOW IN    Anywhere 443/tcp                    ALLOW IN    Anywhere 22 (v6)                    ALLOW IN    Anywhere (v6) 22/tcp (v6)                ALLOW IN    Anywhere (v6) 80/tcp (v6)                ALLOW IN    Anywhere (v6) 21/tcp (v6)                ALLOW IN    Anywhere (v6) 443/tcp (v6)               ALLOW IN    Anywhere (v6)   Am I missing something? Any help would be highly appreciated.  EDIT  here my exemple.net-ssl.conf  <VirtualHost *:443>          ServerName exemple.net         ServerAlias www.exemple.net         DocumentRoot /var/www/exemple.net/         CustomLog /var/log/apache2/secure_access.log combined          SSLEngine on         SSLCertificateFile /etc/ssl/certs/exemple.net.crt         SSLCertificateKeyFile /etc/ssl/private/exemple.net.key         SSLCertificateChainFile /etc/ssl/certs/GandiXXXSSLCA.pem         # SSLVerifyClient None    </VirtualHost>

I'm just playing with apache and i got it to work, that is i can connect to server by browsing to http://127.0.0.1 and http://192.168.1.5 i'm NOT running IPv6  Yet this is the result of netstat  $ sudo service apache2 status  * apache2 is running $ netstat -an | grep :80 tcp6       0      0 :::80                   :::*                    LISTEN  $ wget 127.0.0.1 --2014-06-26 01:32:15--  http://127.0.0.1/ Connecting to 127.0.0.1:80... connected. HTTP request sent, awaiting response... 200 OK Length: 11510 (11K) [text/html] Saving to: ‘index.html’  100%[=====================================================================================================>] 11,510      --.-K/s   in 0s        2014-06-26 01:32:15 (161 MB/s) - ‘index.html’ saved [11510/11510]   I was expecting to see it listening on a regular TCP which it clearly does!?  Edit:  $ netstat -a | grep LISTEN tcp        0      0 localhost:ipp           *:*                     LISTEN      tcp        0      0 localhost:mysql         *:*                     LISTEN      tcp6       0      0 ip6-localhost:ipp       [::]:*                  LISTEN      tcp6       0      0 [::]:https              [::]:*                  LISTEN      tcp6       0      0 [::]:http               [::]:*                  LISTEN        Edit2: Why the down vote? What am i missing can someone elaborate?


Although I use the option [H] or small case analogue of it [h], my figure is placed separately from the text how can I solve this issue? I tried to provide a minimal working example but this may not illustrate my problem since the document is much more complex than this cut-down version. The minimal working example is:  \documentclass[11pt]{article} \usepackage[utf8]{inputenc} \usepackage[a4paper]{geometry} \usepackage{graphicx} \begin{document} \subsection{Soliton Evolution} We begin our analysis by simulating the evolution of a third order soliton in the PCF Thorlabs NL-PM 750. This procedure of investigating soliton evolution is usually employed to test the accuracy of the code since solitons are analytical solutions of the NLSE, that is Eq.(\ref{eq:NLSE}).\cite{3} In order to conform with the analysis in the thesis and the article by the Dudley group we select the parameters corresponding to a third order soliton in our fiber\cite{thesis, 6}: \begin{equation} \begin{split} L_D &= \frac{T_{0}^{2}}{|\beta_2|}= 0.158242\ \si{\meter}\\ L_{NL}&=(\gamma P_0)^{-1}= 0.017602\ \si{\meter} \\ P_0& = 598\ \si{\watt} \\ N &= [L_D / L_{NL}]^{1/2} \cong 3 \\ Z_{soliton}&=(\frac{\pi}{2})L_D= 0.248566 \ \si{\meter} \end{split} \end{equation} \begin{figure}[H]\capstart     \centering     \includegraphics[scale=0.5]{SolitonEvolution(3rdOrder).jpg}     \caption{The evolution of a third order soliton with the central wavelength of 790 \si{\nano\meter}.}     \includegraphics[scale=0.5]{SolitonEvolution(3rdOrder)Solperiod.jpg}     \caption{The same soliton with the length scale expressed in terms of the soliton period.} \end{figure} \subsection{Soliton Fission} When we introduce the Raman scattering into the NLSE by modifying it as follows: The parameters selected correspond to a third order soliton and is the same as before. \end{document}

How to influence the position of float environments like figure and table in LaTeX?   This is a general question and should collect useful answers for all users. I hope we can use this as a reference


I have a question on voting system of SO. So I have seen a trend among some community members that they prefer to first downvote  the question and then point out the corrections they were hoping to see in the comments section and once it's done and they cancel their downvote.  No problems in that except that as I have read in the Reputation system of SO, it is written that on cancelling the downvote to the  question you will be awarded +2. That means there is a net loss of 3 reputation. Now the thing is, judging the quality of the question is a subjective thing. This could lead to good loss of reputation of OP. I don't think many community members know of this rule.  Today I faced this situation. Though the member didn't intentionally wanted to create me a loss of reputation, but it did. I think a  little hovering message while downvoting can go a long way to prevent this.

On Stack Exchange, users may gain a certain level of reputation.  What does reputation do? How can a user gain or lose reputation?   See also   in the Help Center  - Maximum amount of votes a user can use in a day and reputation requirements to vote.  - How to get an exact overview of the actions that got you your reputation.  - A full list of all privileges granted at each reputation level on all sites.


I want to obtain the ASCII number of a character, so I have the following:  VAR="a" NUM=$(printf "%d" "'$VAR") echo $NUM   What does '$ mean in this context? Can someone point me to a documentation to understand the syntax? I don't understand if its part of $(...) or printf or bash.

I just saw this in an init script: echo $"Stopping Apache"  What is that dollar-sign for? My research so far: I found this in the bash manual:  extquote  If set, $'string' and $"string" quoting is performed within ${parameter} expansions enclosed in double quotes.  This option is enabled by default.   ...but I'm not finding any difference between strings with and without the $ prefix: $ echo "I am in $PWD" I am in /var/shared/home/southworth/qed $ echo $"I am in $PWD" I am in /var/shared/home/southworth/qed $ echo $"I am in ${PWD}" I am in /var/shared/home/southworth/qed $ echo "I am in ${PWD}" I am in /var/shared/home/southworth/qed $ echo 'I am in ${PWD}' I am in ${PWD} $ echo $'I am in ${PWD}' I am in ${PWD} $ echo $'I am in $PWD' I am in $PWD


When used to cast another spell, Wish states:     You don't need to meet any requirements in that spell, including costly Components.   (PHB 288) Contingency states:     ...contingency ends on you if its material component is ever not on your person.   (PHB 227) Does this mean that, when cast via Wish, you are always considered to have the statuette on you?

How does  work with spells that interact with material components?  For example, how does wish work with a spell like ? Do an exquisite chest and small chest just appear with the wish? Or do you need them?   Wish says it doesn't need any expensive components to cast, but things are a bit unclear here.


In the Wizarding World, there are people like Madame Pomfrey and the staff of St. Mungo's who are devoted to the art of magical healing.   There doesn't seem to be a class at Hogwarts for it, and the brief amount that is taught in class (e.g. Slughorn's Potions class where they made an antidote) doesn't seem to be enough training for a career.  So how do they learn magical healing?

What training do doctors/Healers receive above their school education?   A fresh Hogwarts graduate does not seem to have all the skills required to be a Healer, so s/he would need to be learning those skills somehow/someplace. So how/where do they get those skills?  Also, there is one instance of a doctor being praised for inventing a healing spell. Is there any research system, like funding, trials etc or any other source of innovation?


I'm creating a shopping cart using servlets. I've got a form in a .html file which send it to the post method of my servlet. Here's the form: .HTML File     <form action="Sess04" method="post">                      Nazwa:             <input type="text" name="name">
                      Ilość:             <input type="number" name="quantity" min="1">
                      Cena:             <input type="number" name="price" step="0.01" min="0">
                      <input type="submit" value="Dodaj do koszyka">              </form>  Here's my servlet (doPost method, doGet is empty for now):     HttpSession sess = request.getSession();         List<Item> itemsList = (List<Item>) sess.getAttribute("cart");         if (itemsList.isEmpty()) {                           ← Here NullPointException             itemsList = new ArrayList<>();         }         String name = request.getParameter("name");         int quantity = Integer.parseInt(request.getParameter("quantity"));         double price = Double.parseDouble(request.getParameter("price"));          Item item = new Item(name, quantity, price);         itemsList.add(item);         sess.setAttribute("cart", itemsList);          for (int i = 0; i <= itemsList.size(); i++) {             response.getWriter().append("Product " + i + " - " + quantity + " x " + " " + price + "USD" + " = " + quantity*price + "USD");         }  When I open the index in my browser, add the item and submit, it returns me the NullPointerException in the marked place (if). Why is that happening?

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?


Prove that for every natural number $n$ and for every real numbers $x\neq \dfrac {k\pi}{2^t }$ $(t=0,1,....n;)$ (where $k$ is any integer) $$\dfrac {1}{\sin 2x}+\dfrac {1}{\sin 4x}+.....+\dfrac {1}{\sin 2^n x}=\cot x-\cot 2^nx$$

Prove    $$ \frac{1}{\sin 2x} + \frac{1}{\sin 4x } + \cdots + \frac{1 }{\sin 2^n x} = \cot x - \cot 2^n x $$   where $n \in \mathbb{N}$ and $x$ not a multiple of $\frac{ \pi }{2^k} $ for any $k \in \mathbb{N}$.   My try. If $n=2$, we have  $$\begin{align} \frac{1}{\sin 2x} + \frac{ 1}{\sin 4 x} &= \frac{1}{\sin 2x} + \frac{1}{2 \sin 2x \cos 2x } \\[6pt] &= \frac{ 2 \cos 2x + 1 }{2 \sin 2x \cos 2x} \\[6pt] &= \frac{2 \cos^2 x - 2 \sin^2 x + \cos^2 x + \sin^2 x}{2 \sin 2x \cos 2x} \\[6pt] &= \frac{3 \cos^2 x - \sin^2 x}{2 \sin 2x \cos 2x} \end{align}$$  but here I got stuck. I am on the right track? My goal is to ultimately use induction.


Example:  PIN Number (PIN=Personal Identification Number), no need to repeat number  RSVP please (RSVP=Answer please in French), no need to say please again  etc.

We often say "PIN Number", this is part of everyday conversation. But why?  PIN stands for Personal Identification Number, so what we're actually saying is Personal Identification Number Number.  Is there a reason for this?