I am writing a thesis document in Latex. I have already written several pages in it but suddenly at one page the spacing between paragraphs is too much (3-4 lines).   As its a long documents so, its a bit difficult for me to provide the working example. I was wondering if somebody has also faced the similar problem or know the possible reason of this weird results.  By the was, I am writing the paragraphs in the following way:  Here the para-1 ends.   The para-2 begins here after a gap of one line. Now, it ENDS here.  Para-3 has started with a gap of one line.   PS: it is a single sided document   UPDATE:  I have found that if I remove the line below the equation then everything become ok but if i put the line below the equation then, the problem of weird spacing comes. I have used the same method of putting equation and paragraphs in other sections but did not face any problem.  \begin{gather} \text{positional distance component, } d_p(i,j) = \sqrt{            (   n_x^i - n_x^j   )^2 + ( n_y^i - n_y^j   )^2     } \\ \text{and color distance component, } d_c(i,j) = \sqrt{         (   n_L^i - n_L^j   )^2 + ( n_a^i - n_a^j   )^2 + ( n_b^i - n_b^j   )^2     } \end{gather}  The weightage of the two distance components can be varied by chaning the value of two multiplying constants ($\mathit{w_p}$ and $\mathit{w_c}$) for position and color components of distance measure.

I have a problem. I have several large equations within the text. And when LaTeX does not manage to put the equation on the same page and moves it to the next one, he spreads the paragraphs of the text in the first page. How could I prevent this? I know about \pagebreak and \newpage, but I do not want to force the \newpage, as the text may move (if I add something later or so on) and the pagebreaks may not be valid. I would like to make LaTeX not to spread the paragraphs over a page automatically. Is it possible?  I tried to make an example:  \documentclass[a4paper,12pt,twoside]{book} \usepackage{amsmath} \begin{document}  LaLaLa\\\  LaLaLa\\\  LaLaLa\\\  LaLaLa\\\  \begin{eqnarray} 123&+&123 \\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ \end{eqnarray}  LaLaLa\\\  LaLaLa\\\  \begin{eqnarray} 123&+&123 \\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ 123&+&123 \nonumber\\\ \end{eqnarray}  \end{document}


According to     $ sudo wget http://master.dl.sourceforge.net/project/d-apt/files/d-apt.list -O /etc/apt/sources.list.d/d-apt.list --2018-03-18 21:39:27--  http://master.dl.sourceforge.net/project/d-apt/files/d-apt.list Resolving master.dl.sourceforge.net (master.dl.sourceforge.net)... 216.105.38.12 Connecting to master.dl.sourceforge.net (master.dl.sourceforge.net)|216.105.38.12|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 85 [application/octet-stream] Saving to: ‘/etc/apt/sources.list.d/d-apt.list’  /etc/apt/sources.list.d/ 100%[==================================>]      85  --.-KB/s    in 0s        2018-03-18 21:39:28 (4.05 MB/s) - ‘/etc/apt/sources.list.d/d-apt.list’ saved [85/85]  android@android:/$ sudo apt-get update && sudo apt-get -y --allow-unauthenticated install --reinstall d-apt-keyring Hit:1 http://np.archive.ubuntu.com/ubuntu artful InRelease Hit:2 http://np.archive.ubuntu.com/ubuntu artful-updates InRelease                                  Hit:3 http://np.archive.ubuntu.com/ubuntu artful-backports InRelease                                Ign:4 http://dl.google.com/linux/chrome/deb stable InRelease                                        Get:5 http://security.ubuntu.com/ubuntu artful-security InRelease [78.6 kB]                         Hit:6 http://ppa.launchpad.net/christian-boxdoerfer/fsearch-daily/ubuntu artful InRelease           Ign:7 http://download.opensuse.org/repositories/home:/manuelschneid3r/xUbuntu_17.10  InRelease      Hit:8 http://dl.google.com/linux/chrome/deb stable Release                                          Get:9 http://download.opensuse.org/repositories/home:/manuelschneid3r/xUbuntu_17.10  Release [1,014 B] Get:10 http://master.dl.sourceforge.net/project/d-apt d-apt InRelease [4,878 B]                     Hit:11 http://ppa.launchpad.net/haraldhv/shotcut/ubuntu artful InRelease                            Err:10 http://master.dl.sourceforge.net/project/d-apt d-apt InRelease            The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EBCF975E5BA24D5E Hit:14 http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu artful InRelease Hit:15 http://ppa.launchpad.net/libreoffice/ppa/ubuntu artful InRelease         Hit:16 http://ppa.launchpad.net/system76/pop/ubuntu artful InRelease            Reading package lists... Done                       W: GPG error: http://master.dl.sourceforge.net/project/d-apt d-apt InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EBCF975E5BA24D5E E: The repository 'http://master.dl.sourceforge.net/project/d-apt d-apt InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

I added some extra repositories with the Software Sources program. But when I reload the package database, I get an error like the following:     W: GPG error:  trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8BAF9A6F   I know I can fix it using apt-key in a terminal, according to the official Ubuntu documentation. But I would have liked to do it graphically. Is there a way to do this without using a terminal?


I added dropboxd as a service using the following dropbox.service unit file:  [Unit] Description = Dropbox Daemon After = network.target  [Service] User = john ExecStart = /home/john/.dropbox-dist/dropboxd  [Install] WantedBy = graphical.target   Once I enable it, it works in the sense that dropboxd is running and syncing, but the dropbox icon doesn't show up in the upper right corner like it does when I start dropboxd manually in the terminal.  The main reason I care is because I want to be able to open the settings and adjust the selective sync folders.  Is there another dependency I can add to the unit file to make that icon show up like normal?

I installed Dropbox on Xubuntu 14.04 using the package provided by Dropbox on its download web page.  Now, Dropbox works, but its icon does not show in the panel at startup, and I have to run dropbox stop && dropbox start in a terminal in order to get it.  I read that a simple workaround is to install package nautilus-dropbox via apt-get.  There are 2 issues:   I don't know how to uninstall Dropbox safely, without messing anything up. My Dropbox folder is already synced on my PC. Once I install nautilus-dropbox, I'd like to make it read this folder without resyncing all that stuff. Is that feasible?


I have a client who needs their users to run multiple local Windows virtual machines on their laptops. Some users have 3-5 VMs, while others have 10+. I'm aware of the following two routes for licensing guest (desktop) operating systems:   Purchase a retail/FPP license for each VM. Purchase Software Assurance for the host, and leverage the virtualization rights.   The second option works well for up to 4 (well, technically 3) VMs, but beyond that, are there any options aside from simply purchasing retail licenses for the remaining VMs?    I've considering working around this by purchasing a second Windows license for each host and then purchasing software assurance for that license, thus giving an additional 4 VMs via virtualization rights. From the Microsoft perspective, this is no different than if each employee simply had another laptop. Is this a valid strategy?  For context, VDI-like solutions are off the table here, as the users in question are frequently in remote locations with limited internet connectivity. They're also regularly remoting to other systems within those VMs, and I don't want to introduce another hop of latency into that equation.  Also for context, these VMs are, by Microsoft definition, production systems. Any solution involving MSDN or "developer" licenses isn't going to work here.

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


I would like to know, if my proof to the below problem is correct.     Show that if $x_{n}\ge0$ for all $n\in\mathbb{N}$ and $\lim{(x_{n})}=0$, then $\lim({\sqrt{x_{n}}})=0$.   Proof.  It is given that $\lim({x_n})=0$. This means that,  $(\forall\space{\epsilon>0})(\exists{K\in\mathbb{N}})$ s.t. $(n\ge{K})\implies|x_{n}-0|=x_{n}<\epsilon^2$  $\therefore{x_{n}}<\epsilon^2\implies{\sqrt{x_{n}}<\epsilon}$ for all $n\ge{K}$.  Thus, $|\sqrt{x_{n}}|<\epsilon$ for all $n\ge{K}$.  Hence, $\lim(\sqrt{x_{n}})=0$.

Let $x_n \geq 0$ for all $n \in N$. If $(x_n) \to 0$, show that $(\sqrt{x_n}) \to 0$  Unless I am missing something, this seems simple to me. Since $x_n$ converges for an arbitrary $\epsilon^2>0$, we have $|x_n| <\epsilon^2 $ for $n\geq N$. Taking square roots here we have $\sqrt{x_n}<\epsilon$ for all $n\geq N$ which is what we needed to show. Is that all? If so, then why $x_n \geq 0$ is important?


I have a simple question.  I have a disc particion to C, D and E on my Windows XP and I want to install Ubuntu.   Will I lose all my files from D and E (it's like 50 gb, and I don't have an external HDD) when I install Ubuntu? Or the system while installing it offers me options to save my files somewhere or...?

I need my pre-installed version of Windows 7 (or any other version of Windows), how could I install Ubuntu without erasing it?


I am trying to append some config to another file like this  sudo cat config/add-this.yml >> ~/docker-compose.yml   via shell script. But trying this gives me a Permission denied error.  How can I simply append some content to another file?

I am trying to follow what I assume is best practices of using sudo instead of root account.    I am running a simple concat file operation such as:  sudo echo 'clock_hctosys="YES"' >> /etc/conf.d/hwclock   This fails as to the right of the ">>" it is running as the normal user.  Adding extra sudos also fails (expected behaviour since piping to the sudo command and not to the file).  Example is just that but it has been verified and tested under the root account.


My husband and two daughters, ages two and six, are all dual American/Canadian citizens.  We are traveling to England in less than two weeks.   I am kicking myself because I realized today that my six-year-old’s US passport just expired, and I don’t think it will be possible for me to renew it before we travel on August 18th. However, her Canadian passport is still valid. Will this be a problem when it comes time to return to the US from England after our 10 day trip?   My husband and two-year-old daughter will each carry both of their passports, and I will only carry my American one since that is all I have. We can also bring my six-year-old’s birth certificate if that will help.   We have never traveled outside of the US and Canada as a family together, so this is new to me. Part of me feels like how could they possibly give us trouble or not let us back into the US when we all have valid passports, one of them will just happen to be Canadian, but Canadians are allowed into America, especially when they are six years old and both of their parents are American!   However, I don’t want to assume anything, but since our situation is somewhat unique, I don’t really know who to ask for help. Does anybody foresee a problem with this? I can also bring her expired US passport just to further document the situation.  I am so angry at myself for letting her US passport expire, and not even thinking about it until right before our trip! I’m really hoping that I’m worried over nothing, since a Canadian passport is a legitimate travel document, but I just don’t want any trouble at customs or immigration.  TLDR: Can a 6 year old duel American/Canadian citizen travel out of and back to the US on their Canadian passport if their US passport has expired?

Answers to a  mention that it is illegal for a US citizen to enter/leave their home country on a foreign passport. However this raises the following questions:   What is the maximum prescribed penalty for violating these rules? Are US immigration officials known for actually applying the penalty? E.g. the Cuba embargo banning visits to Cuba was almost never enforced, so it's possible this law is ignored as well.


I have to run a program that I don't really trust and I afraid that it may mess up my computer. It is a Windows program so I have to run it in Wine, but I don't want it to access anything outside the virtual C drive. Is it possible somehow?

Can wine as a whole or the windows applications installed via wine pose some kind of risk to an Ubuntu installation? This question arose in my mind when I read this answer to my earlier question :     Try installing PlayonLinux from   playonlinux.org and install IE via   PlayonLinux. and use IE only for those   pesky sites :) - Received 1 downvote      And enjoying the risks of IE? No   thanks - This comment received 2   upvotes   I believe this PlayOnLinux works as a frontend to wine making installing tasks easier.  In totality, I want to know if it is safe to install Internet connecting applications like IE via Wine? Is there any remote possibility of being subject to more online attacks and virus threats this route. I plan to use IE only for browsing websites not accessible with other browsers, like the one in earlier question.


Leia was feisty in her youth. Before ROTJ, did she never get into a situation where her Force powers might show by accident?

According to  (better citation needed), Yoda said to Luke:     The Force is strong with your father, you, and your sister.   Did Leia ever use The Force?


I recently tried to answer I few questions on Stack Overflow. By doing so, I noticed that almost every single time people post a wild draft and edit the post afterwards. It seems to be a common practice to include everything that might be helpful from other answers as well. It has the feeling that it is not about sharing knowledge and help people - it is all placing your answer on top - and ultimately about reputation. I am definitely not the only  one .  Moreover, I noticed that some classic questions like char[] or String for passwords  long time ago. Now a few people generate more and more reputation points from these answers.  Don't get me wrong. Whenever I have a problem I know that I can find the answer probably on Stack Overflow - or at least someone who knows the answer.  However, am I simply too late?

It seems that all good questions that could be asked have been already asked. Also it seems all good answers that could appear have already appeared. Existing questions/answers base probably covers most of the programming topics. And, therefore, it is more difficult to ask an interesting question that bothers everybody than, for example, couple of years ago when SO was comparatively empty. Do only I get this feeling or not? Are there any metrics for proving/disproving that it is more difficult to get more reputation on SO as time passes? I want to get rid of the feeling that all questions have been asked and answers have been already answered.  UPD: Maybe Jon Skeet would be great candidate for the experiment of getting statistical data about SO reputation dynamics? We can track dynamics of his reputation over the last (two) year(s). Maybe it could tell us much. Is there any right way to get such data easily?  UPD2: Here is some info about Jon Skeet dynamics:


Is it significantly easier to reverse a SHA-256 hash if you know that the input was a 32 byte output of SHA-256?  I assume for most outputs of SHA-256 there will be zero, one or two possible 32 byte inputs.  Mapping and storing all of the values is infeasible, but I am still worried that constraining the input to being exactly 32 bytes may weaken SHA-256.  Is this a valid concern?

According to , "SHA-256d" was proposed in one of the Ferguson/Schneier books like so:  SHA-256d(x) = SHA-256(SHA-256(x))   Apparently, the motivation for this construction is to avoid length extension attacks.  Incidentally, SHA-256d is the hash function forming the core of Bitcoin.  According to the comment on the answer linked above, "some minor weaknesses" are known in SHA-256d. What are they?


I'm trying to add three instance methods to the public interface of class 'Fraction' that all return a 'Fraction' as a result:  add, subtraction and multiplication. is it possible to change it from my current code into instance methods?  I just can't get it to work  Here is my code:  class Fraction {     private Integer numerator;     private Integer denumerator;      public Fraction(Integer numerator, Integer denumerator) {          int gcd = 1;          for (int i = 1; i <= numerator && i <= denumerator; i++) {             if (numerator % i == 0 && denumerator % i == 0)                 gcd = i;         }         this.numerator = numerator / gcd;         this.denumerator = denumerator / gcd;     }      public Fraction(Integer numerator) {         this.numerator = numerator;         this.denumerator = 1;     }      public String toString() {          return numerator + "/" + denumerator;     }        public static Fraction add(Fraction f1,Fraction f2){         return new Fraction(f1.numerator*f2.denumerator+f2.numerator*f1.denumerator,f1.denumerator*f2.denumerator);     }     public static Fraction subtract(Fraction f1,Fraction f2){         return new Fraction(f1.numerator*f2.denumerator-f2.numerator*f1.denumerator,f1.denumerator*f2.denumerator);     }     public static Fraction mul(Fraction f1,Fraction f2){         return new Fraction(f1.numerator*f2.numerator,f1.denumerator*f2.denumerator);     } }  class Main {     public static void main(String[] arguments)     {         final Fraction HALF = new Fraction(1, 2);         final Fraction THREE_FIFTH = new Fraction(3, 5);         System.out.println(HALF.add(HALF, THREE_FIFTH).toString());         System.out.println(THREE_FIFTH.subtract(HALF, THREE_FIFTH).toString());         System.out.println(HALF.mul(HALF, THREE_FIFTH).toString());     } }

Is it possible to call a constructor from another (within the same class, not from a subclass)? If yes how? And what could be the best way to call another constructor (if there are several ways to do it)?


\refcheck does not work with biber apparently, as in the following example. Does anyone have a work-around? What do you guys use instead?  % arara: pdflatex % arara: biber % arara: pdflatex % arara: pdflatex  \begin{filecontents}{\jobname.bib} @BOOK{foo:2012a,   title = {My Title One},   publisher = {My Publisher One},   year = {2012},   editor = {My Editor One},   author = {Author One} }  @BOOK{foo:2012b,   title = {My Title Two},   publisher = {My Publisher Two},   year = {2012},   editor = {My Editor Two},   author = {Author Two} }  @BOOK{foo:2012c,   title = {My Title Three},   publisher = {My Publisher Three},   year = {2012},   editor = {My Editor Three},   author = {Author Three} } \end{filecontents}  \documentclass{article}  \usepackage{refcheck} \usepackage[backend=biber,natbib=true,backref=true,doi=true,url=false,style=alphabetic]{biblatex} \addbibresource{\jobname.bib}   \begin{document}  Hello world \cite{foo:2012a,foo:2012b}.  \nocite{*}  \printbibliography  \end{document}

I need two bib-like sections: a "References" giving works explicitly cited in my text, and a "Bibliography" (or "Further reading" if you prefer) giving everything from my bibfile that didn't already appear in "References". The first is of course completely standard, but the second... I'm stumped.  Further loose constraints: I'm somewhat committed to biblatex and the biblatex-apa style. But I'll happily accept an answer not related to them if there's any chance I can adapt it.


Where do I find the license information for a track on soundcloud? I know this question has been asked here before, but I didn't find what was referenced here:   Maybe I am missing something painfully obvious. In that case, please forgive my ignorance.

Is it possible to see what license an individual song has on Soundcloud? Some of the songs have Creative Commons but others appear to not have any license.


This is a simple code that focuses on the problem so I can apply this to the actual program.   The first class has the array. The second I want it to print array elements to the scanner. This code gives me a null pointer exception. I tried using an int instead of int array but still got the same exception. How can I fix this?  public class passthrough{    public void main(String[] args){    PassTry k = new PassTry();     System.out.println(k.pass);    System.out.println(k.her);    }  }//class  public class PassTry{   public int[] pass;    public int her;    public PassTry(){      her = 2;      pass = new int[]{4, 5, 6, 2};    }//constructor    public int res(){     return  this.her;    }//res method  }//class

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


What would you call a situation where the current one sucks but you have a 'choice' to an alternative, however the alternative is not really one.  Such as,       "Sure living in an area under a monopoly internet provider sucks, but   you can always live without internet"     Demonstrating an issue where one of the choices isn't really a viable choice or at least comparable alternative.  (There are more dramatic ones)

First Q here. If this has been asked before sorry (Did search)  Term for a choice that you like and you dislike? And you can/would probably only take the choice you like.  For example:  A justice department lawyer says to you "Either testify or go to prison for 25 to life". Or "Enter witness protection or Vito is going to put you in the ground".  In the above statements, we have two choices. But only one choice is viable. "To testify", or "Enter witness protection".  What is such a choice called? (It can not be called a dilemma).


I became target of mass downvote after I deleted one of the questions I asked (revenge downvoting for not upvoting the answer?) and now I can't ask any question again. What can I do now?

I just noticed that I lost a bunch of points from my reputation score, and I used the "reputation" tab on my user profile page to try and track down the cause.  During my investigation, I noticed there was an unusual event of type "reversal". In the normal place of a question title, it says "voting corrected".     What does this mean, and what caused it?  Did I do something wrong? Why did I lose all of that reputation? Is the system punishing me for leaving too many good answers?  Is there any way to earn it back?


How do I find all homomorphisms between $S_3 \to \mathbb{Z}_{15}$? I know that since $S_3 \cong \langle x,y: x^3 = y^2 = e;yx = x^2y\rangle$, the homomorphism is dependent on $\phi{(x)}$ and $\phi{(y)}$. $\phi{(x)}$ must have order of $1$ or $3$ and $\mathbb{Z}_{15}$ has elements of both $1$ and $3$. How do I proceed from here?

The question  got me curious and thinking about the following:   For which $n$ and $k$ are there nontrivial homomorphisms from the symmetric group $S_n$ to the cyclic group $\mathbb{Z}/k\mathbb{Z}$ of order $k$? I'm thinking it might be an open problem. Is this a problem with a known solution? If so, how can we prove it?   Thanks!


I have the following preamble and I want the subsection not to be visible in the text.  Instead of Chapter 1 "Blah Blah" I only want "Blah Blah to be visible. With this code I did it bu the subsections are still visible in the text. e.g. 2.5 "blah blah".  How can I also remove 2.5 ??  \documentclass[a4paper,12pt]{book} \usepackage{titlesec}  \titleformat{\chapter}[display]{\normalfont\huge\bfseries}{}{20pt}{\Huge}  \let\cleardoublepage\clearpage \usepackage[english,greek]{babel} \usepackage[utf8x]{inputenc} \usepackage{blindtext} \usepackage[pdftex]{graphicx} \usepackage[skip=2pt, font=small, labelformat = empty]{caption}  \newcommand{\gr}{\selectlanguage{greek}} \newcommand{\en}{\selectlanguage{english}} \usepackage{wrapfig} \usepackage[paperwidth=17cm, paperheight=24cm]{geometry}   \usepackage[onehalfspacing]{setspace} \usepackage{textcomp} \useshorthands{;} \defineshorthand{;}{?} \usepackage{fancyhdr} \fancyhf{} \fancyhead[LE]{\nouppercase{\leftmark}} \fancyhead[RO]{\nouppercase{\rightmark}} \fancyfoot[LE,RO]{\thepage} \pagestyle{fancy}  \renewcommand{\chaptermark}[1]{ \markboth{#1}{} } \renewcommand{\sectionmark}[1]{ \markright{#1}{} }

Hello I am trying to further modify my TOC.  I got an answer  as to how I could remove the \section numbers on the left side of the TOC and now I would like to expand that.  I would like to remove the left-hand numbering for \subsection and \subsubsection as well but I do not know how.  (I also want to keep these numbers out of the document and I am using \def\sectionformat{} to do that)  Also, my TOC is slightly over one page and so I would like to adjust the spacing from 2 to 1.5,  is there any way to do this?    \documentclass[12pt, a4paper, twoside]{article}     \usepackage{baskervald}     \usepackage[margin=1in,bindingoffset=15.5mm,heightrounded]{geometry}     \usepackage[T1]{fontenc}     \usepackage[notes]{biblatex-chicago}     \usepackage{filecontents}     \usepackage{microtype}     \usepackage{url}     \usepackage{makeidx}     \usepackage{indentfirst}     \usepackage{setspace}     \usepackage{chngcntr}\counterwithin*{footnote}{section}     \newcommand*{\textsubscript}[1]{$#1{}$}     \DefineBibliographyStrings{english}{references = {Works Cited}}     \DeclareBibliographyCategory{primary}     \makeindex     \addbibresource{bibliography.bib}     \makeatletter     \let\latexl@section\l@section     \def\l@section#1#2{\begingroup\let\numberline\@gobble\latexl@section{#1}{#2}\endgroup}     \def\@seccntformat#1{\ifcsname #1format\endcsname\else\csname the#1\endcsname\quad\fi}     \def\sectionformat{}     \def\subsectionformat{}     \def\subsubsectionformat{}     \makeatother     \author{}     \title{\vspace*{36 pt}\textbf{\emph{\Huge{Big Important Title}}}\vfill}     \date{}     \begin{document}     \tableofcontents     \section{Part I}     Hello World     \end{document}


I encountered a problem when doing my real analysis assignment. The question is:     Assume $x_n>0$ for every $n\in\mathbb{N}$. Show that $\underset{n\rightarrow\infty}{\lim}{\sup}\sqrt[n]{x_n}\leq \underset{n\rightarrow\infty}\lim{\sup}\frac{x_{n+1}}{x_n}.$   I have no ideas how to prove it. Can someone help or give a hint about this?

Let $(c_n)$ be a sequence of positive numbers.  Could someone make the proof of the inequality  $\displaystyle\limsup_{n\to\infty}\sqrt[n]{c_n}\leq\limsup_{n\to\infty}\frac{c_{n+1}}{c_n}$  into a hinted exercise?


Evaluate  sum of the series:  $\displaystyle \sum_{n=0}^\infty {1\over n!(n^4+n^2+1)}$  Comparison test $\left(\text {with } \sum {1\over n^2}\right)$ confirms the convergence of the series. But what's the sum of the series. Using comparison tests I managed to show that ${19\over 14}\le$ sum $\le{e+121\over 91}$. The series seems to converge to $\frac e2$. But how to show that ?


Can anyone explain what is blending in of boosting models and how to combine two models.? How it increases accuracy of model. Any resources are appreciated. And also, its implementation in Python?

This term appears frequently in the .  Is blending a specific method in data-mining and statistical learning? I cannot get a relevant result from google.  It seems blending is mixing up outcomes from many models and resulting in a better result. Is there any resource that helps me knowing more about it?


This line is giving me an error which I have been unable to remove for the last hour.  Let $a^i =p\times 10^{n+1} + r$ and $a^j =q\times 10^{n+1} + r$ be two such powers. Let $a^j \gt a^i$.

\documentclass{article} %\usepackage{amsmath} It does Not work ! \begin{document} \[ x\lt y \gt z \] \end{document}  What library do I have to use such that the document can render \lt and \gt as less than and greater than signs, respectively? Edit I am using MathJax library in my site under Asp.net Mvc 3. Web application is vulnerable to XSS and XSRF attacks so < and > should be avoided as the input from the users. My database will save LaTeX commands that can be rendered by both LaTeX compiler and MathJax. Therefore, I need \gt and \lt that already work in MathJax. Source:  Rendered:


I have looked up the difference but I cannot decide which word to use.   I am talking about my high school experience.  "There was always something to be done, from [this] to [that]. Nonetheless/nevertheless, I learned a lot."  Basically like through the intensity, through the chaos, through doing all the aforementioend things, I learned a lot.   Please tell me which would be correct in the sentence and why. Thanks!

I am never quite sure whether to use nevertheless or nonetheless; they seem almost synonymous to me, but I think I might be missing a subtle distinction. Is there a difference, and if so, how do I determine which is right in different circumstances?  I am specifically thinking of sentences such as these:        I am busy Saturday; nevertheless I will come to your party anyway.   I am busy Saturday; nonetheless I will come to your party anyway.      There is a question  that deals with a specific idiomatic usage, but I was thinking of the general type of usage, as given in the party example above.


I'm writing some code(javascript) to change a base 10 number into base 16. I know base 16 have letters if the remainder is between 10 and 15. This is where I am having trouble. I can't change the remainder into the letter.  so far this what I have:    var mynum = 4053,remainder=[];  while (mynum > 0) {    total = mynum % 16;   remainder.push(total);   mynum = Math.floor(mynum / 16);    switch (total > 9 || total < 16) {     case total === 10:       total = "A";       break;     case total === 11:       total = "B";       break;     case total === 12:       total = "C";       break;     case total === 13:       total = "D";       break;     case total === 14:       total = "E";       break;     case total === 15:       total = "F";       break;   }  }  console.log(total,remainder)     Let's say "mynum" = 4053 then I would get 5,13,15. But I want to get 5,D,F.I also tried using a "for" loop but got the same thing. It feels like i'm close but just missing something something, Can someone please help me?  mynum is the actual number, total is the remainder, and "remainder" is where i put the remainder's in a list

How do you convert decimal values to their hexadecimal equivalent in JavaScript?


We know axiom of choice states that:  Given any collection $\{ S_i : i \in I \} $ of nonempty sets, there exists a choice function $f: I \to \bigcup_{i \in I} S_i $ such that $f(i) \in S_i $ for all $i \in I$.  Question: I am bit confused because in one books I saw the axiom of choice as: For any collection $\{ S_i : i \in I \} $ of nonempty sets, $\prod_{i \in I} S_i $ is non empty.   Why are they equivalent?

I understand that the axiom of choice, given the axioms of ZF set theory, is equivalent to the statement that "the Cartesian product of any family of nonempty sets is nonempty." I've been unable to find this proof. Could someone sketch it for me? Or provide me with a source at least?


I'm new in deep learning.   when applying convolution on the image , the receptive field is increased but when applying max pooling on the image, I don't know the receptive field is increasing or keep  for example  there's an image that has a shape (11,11) when applying convolution that has filters shape (3,3), stride=1 on the image, the output receptive field has 3 but when apply max pooling on the image, I don't know whether the receptive field is 1 or 3.  please Somebody tell me the answer. thank you!

Let's say I have 8 back to back convolutional layers with zero padding such that the input and output dimensions are the same. There are no max-pooling layers between the layers. All the layers use a 3x3 filter. I want to calculate how many pixels influence each of the output layers. How do I go about doing this?   I know that if there is only 1 layer, then each of pixel in the output is influenced by 9 pixels from the input. If there are 2 layers, then I'm guessing there would be 25 pixels influencing each pixel in the output. This is because if the second layer runs a 3x3 filter over layer 1, then those 9 pixels correspond to a 5x5 grid in the input layer. Am I properly calculating this?


Mistakenly, I lost a partition by disk initializing in Win10.  How can I recover it?  The former:   sector size(logical/physical): 512B/4096B partition table: gpt start: 1049kb, end: 4001GB file system: ext4   The latter:   sector size(logical/physical): i don't know it. partition table: gpt  Number  Start (sector)    End (sector)  Size       Code  Name    1              34          262177   128.0 MiB   0C01  Microsoft reserved part    Just the initializing was done.

I was installing ubuntu 12.04 on my system. There were 4 partitions on my system and I selected one of the four partition for the installation and chose the option of resizing the partition. Initially my partition was of size 100+GB and i created another partition out of it of size 15GB (EXT4). Now the moment I changed this partition structure my original partition got lost along with its data and I am left with 50GB partition and 50GB unallocated free space.   Now the data that I have lost is meant a lot to me and I want to recover that data. So is there any way I can recover it? And I haven't checked "format" option while resizing the partition.


I am building a paginated  from ajax-sourced data:  let table = $('#userTable').DataTable({   destroy: true,   "ajax": {url: url, type: 'GET', "dataSrc": ""},   "pagingType": "simple",   "columnDefs": [     // ...   ],    "order": [[3, "desc"]],   "columns": [     { "data": "view", "defaultContent": "" },     { "data": "username" },     { "data": "email", "defaultContent": ""},     { "data": "lastActive"},     { "data": "completed" },     { "data": "_id" }   ],   "fnInitComplete": function(oSettings, json) {     console.log("Finished drawing table");     $('#spinner').addClass('d-none');     $('.view-profile').on('click', getProfile);     $('.btn-delete').on('click', purgeUser);     $('.page-link').on('click', () => {       console.log("Clicked on paginate button")       $('.view-profile').on('click', getProfile);       $('.btn-delete').on('click', purgeUser);     })   } });   I add buttons (.view-profile and .btn-delete) to each row, and add a listener only after the table is initialised using [fnInitComplete][2].  However, on clicking on a paginate button .page-link, the buttons are no longer clickable - how can I re-listen for clicks on paginating?   I've tried adding a timeout function to first wait for buttons to be drawn (.view-profile) and then wait for 1s after clicking on a .page-link before adding $('.view-profile').on('click', getProfile) - but this isn't working. What am I missing?  if($('.view-profile')){   setTimeout(() => {     $('.page-link').on('click', function() {       setTimeout(() => {         console.log("Next page")         $('.view-profile').on('click', getProfile);         $('.btn-delete').on('click', purgeUser);       }, 1000);     })   }, 1000); }

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.


Here's what I do now:   Get CSV file from extrenal source Open it in Calc Apply style (set colors, fonts, etc.) Export as PDF   Is it possible to get rid of step 3? Somehow loading data to already styled document?  Columns on different CSV files are always the same, but rows might have different data.  I am open to other alternatives too.

How do you set the default font used in new documents of LibreOffice Calc? I am using LibreOffice 3.3.2.  Some answers below have been updated for LibreOffice 4 as well.


Whenever I use the \accentedoperators command from spanish, babel, alongside the package newpxmath, the accents on math commands disappear. Not only that, dots on i's disappear as well.  \documentclass[11pt]{book} \usepackage[utf8]{inputenc} \usepackage[spanish.noindentfirst, %don't mind these, just playing with some options and solutions     %mexico,     %es-minimal,     %es-noindentfirst,     %mexico-com,     %es-sloppy, ]{babel} \accentedoperators \decimalpoint  \usepackage{newpxtext} \usepackage[varg]{newpxmath} %if you comment out this line, it works  \begin{document}  \chapter{}  These words should be accented: límite, gráfica, función.   Both of these should use a decimal point: $2.099$ and 2.099.  These words need to be accented: $\lim$, $\max$, $\min$. $$\lim f=\max g=\min h$$  Both of these should have angle quotes: "`John"', <<Juan>>.  \end{document}     This used to work until some time ago, I don't know exactly when it stopped.

Please consider the following MWE:  \documentclass{article} \usepackage[spanish]{babel} \selectlanguage{spanish} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc}  \begin{document} Works: áéà  Does not work: \(\pmod1\) \end{document}   The áéà text is copied correctly, but if I try to copy (mód 1) it says: (m´od 1).  Does anyone know why this happens? How is it solved?  Thanks!


Which of these is it:     Robert and Mike like their presents.   Robert and Mike likes their presents.

Both John and Christina takes an apple        Both John and Christina take an apple.   Which one is correct? Why?


I have completed my animation but I realised when I render it that one of the propellers blades starts to glitch. On some frames it is in shot and some it is out of shot and this is really strange. These 'blades' are both parented to the same 'propeller' and the 'propeller' is parented to the middle ball. I have baked the animation through so this shouldn't be a problem. These propellers are passive rigid bodies. I have tried to figure out this problem and I just can't get to a solution. I've never had it where a rigid body object glitches out like that in the rendered animation, it's almost like it's jumping, which on the render these frames show the object as invisible. The videos attached will show.

I have completed my animation but I realised when I render it that one of the propellers blades starts to glitch. On some frames it is in shot and some it is out of shot and this is really strange. These 'blades' are both parented to the same 'propeller' and the 'propeller' is parented to the middle ball. I have baked the animation through so this shouldn't be a problem. These propellers are passive rigid bodies. I have tried to figure out this problem and I just can't get to a solution. I've never had it where a rigid body object glitches out like that in the rendered animation, it's almost like it's jumping, which on the render these frames show the object as invisible. The video attached will show.   If anyone has experienced problems like this or knows an answer to my dilemma that would be greatly appreciated, thanks!


How can I solve the problem below?  $ sudo apt-get install gtypist sudo: unable to resolve host vanz Reading package lists... Error! E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/ppa.launchpad.net_noobslab_malys-themes_ubuntu_dists_xenial_main_binary-amd64_Packages E: The package lists or status file could not be parsed or opened.

The computer gave me this output in a window:  E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_natty_main_binary-i386_Packages E: The package lists or status file could not be parsed or opened.   How can I fix this?


I've been having problems with a database functional dependency algorithm I have been developing. I am trying to calculate functional dependencies given the current level of the lattice and the list of column heads (not really relevant).  I am trying to iterate through a list of string headers, as well as looping through the characters of each string. Reasoning with this, I then use these values to remove a string from a List<String> value in a map. The Map has structure <String, List<String>> and I want to simply remove a value from the List<String> values of the HashMap. colHeads is a List<String>.  I am getting ConcurrentModificationException when I start to loop through the list:  for (String x: level) {         for (char a : x.toCharArray()) {             if (cPlusHash.get(x).contains(Character.toString(a))) {                 if (checkFD(Arrays.asList(x.replace("a", "")), Arrays.asList(Character.toString(a)))){                     fds.add(x.replace("a", "") +", "+ a );                       cPlusHash.remove(x, Character.toString(a));                        for (char j : x.toCharArray()) {                         if (colHeads.contains(Character.toString(j))) {                             colHeads.remove(Character.toString(j));                         }                     }                     for (String b : colHeads) {                         if (cPlusHash.get(x).contains(b)) {                             cPlusHash.remove(x, b);                         }                     }                 }             }         }   I am getting the error thrown on the first line of this snippet of code. I am confused as I'm not actually trying to modify the value of the List I'm iterating through.

We all know you can't do the following because of ConcurrentModificationException:  for (Object i : l) {     if (condition(i)) {         l.remove(i);     } }   But this apparently works sometimes, but not always. Here's some specific code:  public static void main(String[] args) {     Collection<Integer> l = new ArrayList<>();      for (int i = 0; i < 10; ++i) {         l.add(4);         l.add(5);         l.add(6);     }      for (int i : l) {         if (i == 5) {             l.remove(i);         }     }      System.out.println(l); }   This, of course, results in:  Exception in thread "main" java.util.ConcurrentModificationException   Even though multiple threads aren't doing it. Anyway.  What's the best solution to this problem? How can I remove an item from the collection in a loop without throwing this exception?  I'm also using an arbitrary Collection here, not necessarily an ArrayList, so you can't rely on get.


I am hoping someone can help me out. I co-run a support site for people with mental health problems and suicidal feelings. We scoop up the folks that are searching for suicide methods pulling them away from toxic sites that encourage them to die and to a peer support site encouraging them to seek help and support.  For the last couple of years the articles on our wordpress bridge have ranked really well and we have helped a lot of people.   Right now, I have all kinds of issues suddenly:   Some articles indexed in Google.com but not Google.co.uk e.g:  Some aticles not caching (e.g: ) Some articles that cannot be fetched by Google at all (e.g:  Some articles that did rank top 5 that are indexed and cached but just gone from Google SERPs (e.g: )   I am really anxious about it because these articles are how we drew people away from sites full of methods and hate and we used to have hundreds of people a day seeking support and getting help and now due to (presumably) some tech issue I don't know how to fix, people are slipping through.  I checked search console - the one that can't be fetched I can't see any issue. Robots txt is fine. The rest, even the ones not getting cached suddenly, are inspected and says everything is okay. Site maps are submitted and successful.  Please can ANYONE help?  Thank you so much for your time.

There has been a significant drop (90%) in traffic from Google to one of my well-established sites (6+ years) in the last week. Searches show that the top 3 wide keywords all dropped 4 spots. Searches for other keywords do not show ANY results in the first 10 to 25 pages of results, while previously one 1st or 2nd page at most.  Since there are , the question really is:  What steps are necessary to figure out what caused such a drop?  There have been no major changes during this period or the last month on the site and certainly not in the homepage which has dropped in rank. Over all the years of running this site and plenty of others, I have never experienced this. There are is duplicate content on my site and I have rigorously used canonical links for the last few years to ensure it is not misinterpreted as such.


I am struggling to install VIM on my ubuntu box. I don't understand how to resolve this dependency problem. $ sudo apt-get install vim Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  vim : Depends: libpython3.8 (>= 3.8.2) but it is not going to be installed E: Unable to correct problems, you have held broken packages.  $ sudo apt-get -f install libpython3.8  libpython3.8 : Depends: libpython3.8-stdlib (= 3.8.2-1ubuntu1.2) but 3.8.6-1+bionic1 is to be installed E: Unable to correct problems, you have held broken packages.

After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


I know, I need to pass through UK border control if my transit time is before mid-night next day of my arrival and do not need visa as I have a valid permit to stay and live in Canada (source: ). On my return to Canada through Heathrow, I have a connecting flight from Terminal 2, next day after 18 hours of my arrival at Terminal 4. My confusion is where shall I pass through the border control, at the arrival terminal (T4) or departure terminal (T2). Can I just walk toward border control, or I needed to be told about that?  Please help to reply.  This question is not about weather or not I need transit visa, I want to know at which terminal, arrival or departure, do I need to do my immigration stuff. I am sure, I wont get my borading pass from Heathrow to Canada at my point of origin (issuing boarding pass 24 hours before the flight is not possible).

Is there a website or some other way to find out if I need a transit visa for a short stop in the UK on my way somewhere else? Ideally this should give me the answer for all nationalities, and take into account any other visas I may have.


I need Matlab code, e.g. the one here, in LaTeX and in colour (the comment is green, for/if/else/end is blue).  % super cooles Programm i = 1 for i = 1:10     if i > 3         i=i+2     else          i=i+1     end end   I tried   `\begin{lstlisting} code \end{lstlisting}`   this gave me the code, but not in colour.  I tried  \lstinputlisting[language=Matlab, frame=single]{\MatlabCodeToLaTeX.m}   this gave me the error message, that LaTeX couldn't start the file.  How do I get the code properly colored?

This question led to a new package:      Does anybody have a quick and easy way to typeset some relatively long MATLAB code in the appendix? I looked up a few methods, and the mcode package emerged as a possibility, but it seems to be unmaintained...  I have a ton of equations in my code, so I'd prefer a solution that avoids having to use $ to denote equations.  Also, if possible, if there's a way to keep all of MATLAB's "natural" coding colors (e.g. green for comments), that would be great...  Any idea?


Consider the following folder structure:  . ├── test1 │   ├── nested1 │   ├── testfile11 │   └── testfile12 └── test2     ├── nested1 -> /path/to/dir/test1/nested1     └── testfile21   test2/nested1 is a symlink to the directory test1/nested1. I would expect, if it were the cwd, .. would resolve to test2. However, I have noticed this inconsistency:  $ cd test2/nested1/ $ ls .. nested1  testfile11  testfile12 $ cd .. $ ls nested1  testfile21   touch also behaves like ls, creating a file in test1.  Why does .. as an argument to cd refer to the parent of the symlink, while to (all?) others refers to the parent of the linked dir? Is there some simple way to force it to refer to paths relative to the symlink? I.e. the "opposite" of readlink?  # fictional command ls $(linkpath ..)   EDIT: Using bash

When I cd a link, my current path is prefixed with the link's path, rather than the path of the directory the link links to.  E.g.  ~/dirlinks/maths$ ls -l logic lrwxrwxrwx 1 tim tim 71 Jul 27 10:24 logic -> /windows-d/academic discipline/study objects/areas/formal systems/logic  ~/dirlinks/maths$ cd logic ~/dirlinks/maths/logic$ pwd /home/tim/dirlinks/maths/logic  ~/dirlinks/maths/logic$ cd .. ~/dirlinks/maths$   I would like to have my current path changed to the path of the linked dir, so that I can work with the parent dirs of the linked dir as well. Besides ls the link to find out the linked dir, and then cd into it, what are some simpler ways to accomplish that? For example, after cd into a link, how do you change your current path to the path of the linked dir?


I am trying to install a addon that lets me  files but it is not appearing after I press the button "install from file" and select the file. Here are some pictures of what I do to install it.      As seen above it is nowhere to be found! (sorry for the poor quality pictures)

Why is it that if I go to install an add-on from User Preferences > Add-ons > Install from File... and choose a *.ZIP, some add-ons will install, while others will return me to the User Preferences with nothing having happened (as far as I can tell)?  Is there a specific file structure required in the .ZIP? I get many add-ons from GitHub, using the Download Zip button, and even there installation of the actual Zip file only works some of the time.


I analyzed four binary variables with a binary logistic regression.  I used for the analysis of all four binary y-variables the same set of 9 x-variables (a-i).  My problem deals with one of this four regressions. The results of the binary logistic regression shows that the x-variable "c" takes surprising high values regarding the regression coefficient B, Wald and Exp(B) (see table 1) indicating that this variable problematic.  That is why I excluded this variable "c" from this one of four regressions.  I am now in a difficult situation. I already wrote the scientific publication about this analysis, and I have to send it within a few days to the Journal. When I did this analysis, I asked my supervisor about this one variable c and he said it would be ok to leave this one variable out, whereas I did not do it in the other three regressions. But he is really no expert in statistics.   I am trying to include a few sentences in the paper to explain why I did it. If the Reviewers are not fine with it, it would be o.k.. I would be fine with calculating it again and I think the paper all in all is great, and I would be surprised if I would get a rejection.  But the explanation should be plausible with respect to the special characteristics of this variable c within the regression results. The problem is that I cannot calculate until submitting the paper.  Could you give me some advice? What do you think about the regression results regarding this variable "c"?  (I know, I break the rule of thumb of 10 events per item in logistic regressions; that´s a limitation I already mentioned in this paper)  Table1 regression results    Table2 correlation matrix

If you have a variable which perfectly separates zeroes and ones in target variable, R will yield the following "perfect or quasi perfect separation" warning message:  Warning message: glm.fit: fitted probabilities numerically 0 or 1 occurred    We still get the model but the coefficient estimates are inflated.   How do you deal with this in practice?


I have a mysql table with a character stored as "û" (u with a circumflex). I am exporting this via php to csv. I have tried everyhting but just cant get û in the export file. I do see things like "?" or "È" and "Ã»".   Question: how can I properly export the data from mysql to a CSV file using PHP so I see "û" in the DB as "û" in the exported file?  Our php drill  mb_internal_encoding("UTF-8"); $list = $readConnection->fetchAll($query); $fp = fopen($file, 'w'); setlocale(LC_MONETARY, 'nl_NL');  # Loop over lines here $line = utf8_encode($db_row); fputcsv($fp, $line);   I have also tried adding a BOM fprintf($fp, chr(0xEF).chr(0xBB).chr(0xBF)); // set UTF 8 header, not working

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I'm creating a Persian presentation using xepersian. How can I change blue squares in below code to numbers and make them print in the left of the text? Also I want world be shown properly and inorder. Any answer is highly appreciated:   \documentclass[11pt]{beamer} \usetheme{Berlin} \usepackage{media9} \usepackage{polyglossia} \setdefaultlanguage[numerals=eastern]{farsi} \newfontfamily\farsifont[Script=arab]{Amiri} \newfontfamily\farsifontsf[Script=arab]{Amiri} \begin{document} \begin{frame}{سیب} \begin{itemize}\raggedleft \item it is not ok  \item they printed reversly!  \end{itemize} \end{frame} \end{document}

I'm used to create  Arabic Beamer presentations with the  arabtex package, but with arabtex there are many environments (like enumerate) can not be used, for this I would like to write arabic using new packages such as arabi or polyglossia .  I tried writing my presentations with these new packages but  I always set problems of alignment especially with the polyglossia package .  My aim is to learn the best and easier way to create beamer presentation with arabic script with examples of that   my MWE with arabtex   \documentclass{beamer}   \usetheme{Warsaw} \usepackage{graphicx} \usepackage{arabtex}  \author{Me} \title{Arabic in Beamer}  \begin{document} \novocalize \begin{frame}{} \titlepage \end{frame}  \begin{frame}{\begin{arabtext} al-^sry.hT al-'awlY \end{arabtext}}  \begin{arabtext} $-1$ n.s `rby\\ $-2$ n.s `rby \end{arabtext}  \begin{enumerate} \item \RL{n.s `rby} \item \RL{n.s `rby} \end{enumerate} \end{frame}  \end{document}


I have an array with these values.   $MyArray = array('2','4','4','4','2','2','0','0','0','0','4');   I want do an "array group by" (like in MySql) to only have one occurence of values. I expect something like this  $AnotherArray = array('2','4','0');

How can I remove duplicate values from an array in PHP?


I have a minecraft image as a reference image in my blend file, but it automatically blurs it.  I know how to fix this with materials, but not with ref images.  How do I fix this?

I'm using a low resolution texture (128x64) from an old game as a background image to help me model but it gets blurry (or aliased I guess) which ruins everything.   I heard that one might need to increase the size of texture but if I do that then texture will get messed up and I want to keep all pixels of it in the same place without "JPGing" it.  Is it absolutely impossible to get sharp background image? Zooming doesn't help either. My version is 2.79


I am solving the following : Vector space  $\mathbb{R}$ over rational number   $\mathbb{Q}$ is infinite dimensional.  I proved this by using that $\mathbb{R}$  is uncountable, but my professor suggested a following slightly different method : Suppose that this vector space is finite-dimensional and let {$r_1,...,r_n$} be a basis for it. Then find an element in $\mathbb{R}$ which doesn't belong to $\operatorname{Span}${$r_1,...,r_n$}. I've tried several methods, but it vain. How can I prove this?

It would seem that one way of proving this would be to show the existence of non-algebraic numbers. Is there a simpler way to show this?


Suppose I have a file system like this:  /home/me/dir1/dir2/dir3/dir4/dir5/dir6/file1  Then in /home/me/dir1, I create a symbolic link:  $ cd /home/me/dir1 $ ln -s /home/me/dir1/dir2/dir3/dir4/dir5/dir6 linkdir6   I am trying to copy file1 to my home directory (this is my simplified example, it's more complicated than this - "/home/me/" is actually a much more complicated directory structure, so "~/" is not a solution).  $ cd linkdir6 $ cp file1 ../ $ cd .. $ ls dir2 linkdir6   I don't see file1.  Searching for it, I find it in /home/me/dir1/dir2/dir3/dir4/dir5/file1  It seemed cp didn't realize it was inside a symbolic directory.  How do I cp out of a symbolic folder?  Or, how do I make cp understand that ../ should be dereferenced (where dest in the man page is deferenced)?  Am I missing something?  Is this even possible?  Thanks!  (final note - the actual use case is in a deep directory structure, inside one symlink directory, trying to copy a file ../another-symlink-directory/ without typing complete paths - that's one of the points of symbolic links as far as I'm concerned)

Suppose I have created two folders in /tmp called parent and child. child contains a file called test-child.txt and parent contains a file called test-parent.txt. Now let's go inside the parent and create a symbolic link to the child. Next, go inside the child and try to copy the test-parent.txt from the parent. The bash completion works but the actual file copy fails --   cd /tmp pwd /tmp mkdir parent mkdir child touch child/test-child.txt ls child/ test-child.txt cd parent ln -sf ../child . touch test-parent.txt cd child cp ../test-parent.txt . cp: cannot stat ‘../test-parent.txt’: No such file or directory    why ??  Moreover, when I am inside child and if I say --  pwd /tmp/parent/child


The last few days I'm itching to change the distribution I'm using for years, Debian. Since stability is of major importance for me and I'm not interested in bleeding edge features, I've decided to play around with RHEL. Considering it's not free and being aware of CentOS, I've decided also to make some further investigation to the issue.  While searching, I've found an interesting comment from user  in this , which says the following (among other things):  "Yeah... recompiled sources. But, only Red Hat has the "secret sauce" to compile them correctly. CentOS 6 is 85% different in terms of binary compatibility with RHEL 6."  Which gave further boost to my initial wondering "Red Hat is investing a lot on their OS. Can it be THAT similar with the CentOS? Is there nothing that they can do to make things a little bit more "closed source"? "  And the actual question:  CentOS is considered to be binary compatible with RHEL, but what is the difference from the "real thing"? Is it possible by using different compile configurations to produce an entirely different OS?

I'm sure this question has been asked again and again elsewhere (I did not find anything specific to CentOS vs RHEL in SE), but I would still like to ask and confirm a few specific points.  I am well aware that CentOS removes all RH trademarks, logos, etc. and is based on the same codes with packages built by the community.   Are the packages built for CentOS exactly the same? Will the contents of the packages and the behavior of the programs be identical to those found on RHEL? What is RHN other than a medium for license registration? What is it to CentOS?   I'm an Ubuntu desktop user. Attended a RH299 course which did not really touch anything about the support aspect (i.e. RHN). Other than that I've no professional Linux knowledge or experience.  EDIT  I did read the , but I found the details unsatisfactory. The release notes mentions ,  or  to upstream. But it neither explains nor links to any document detailing what exactly is different in the modified packages. Granted the branding packages are self-explanatory, but it mentions packages like kernel, ntp, anaconda, etc. which have nothing to do with branding as far as I'm aware.


I recently installed Ubuntu 18.04 on my MacBook Pro, this is my first time using a Linux OS.  I do not have an option to connect to wireless internet, though I can use a wired connection with an ethernet cable.   I have tried following the steps in this video:  But this did not fix the problem.    In the comments, I found someone else who had managed to fix the problem, using this series of commands:  sudo apt update sudo apt install git build-essential git clone https://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/backport-iwlwifi.git cd backport-iwlwifi/ make defconfig-iwlwifi-public sed -i 's/CPTCFG_IWLMVM_VENDOR_CMDS=y/# CPTCFG_IWLMVM_VENDOR_CMDS is not set/' .config make -j4 sudo make install sudo modprobe iwlwifi   However, this still will not fix the problem.  EDIT 1: Output for:    lspci -knn | grep Net A3; rfkill list   is here:

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.   What are the steps to install Broadcom wireless drivers for a BCM43xx card?  I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.    lspci -vnn | grep Network showed:   Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b]      iwconfig showed:  lo        no wireless extensions. eth0      no wireless extensions.   NOTE: Answer below is updated every time new information is added and confirmed working.


I just took a look at my activity monitor (to see if I could optimize my RAM), and saw at the bottom of the memory section a huge amount of root tasks simply titled 'cron' (screenshot below).    They don't seem to use that much of memory, but I was wondering what they are used for, and why their are so many (around 60% of all my tasks in memory).  I run macOs Catalina 10.15.3 on a MacBook Pro 16 from 2019.

I have cronjobs doing various cleanup tasks:  $ crontab -l 0 * * * * find ${HOME}/Downloads -depth 1 -d -mtime +12h -exec /usr/local/bin/trash {} \; * * * * * /usr/bin/defaults delete com.apple.Spotlight userHasMovedWindow > /dev/null * * * * * /usr/bin/defaults delete com.apple.Spotlight windowHeight > /dev/null   However, it seems the jobs, for some reason, never exits. Instead they linger on and show as (cron) companioned by either (find) or (defaults) in the output of ps and in the activity monitor.  It happens for all jobs.  After hours or days, the computer freezes as the OS won't allow any more processes to spawn.  $ sw_vers  ProductName:    Mac OS X ProductVersion: 10.15 BuildVersion:   19A583


I was pasting results from Google Translate into a quote in a question and it looked like this     By overlaying the more because    In reality the markdown is this  >By overlaying the more because <What is the other side  ` Ru to one representing the thumb of muscle  < To SenWataru and ho stick base of Ne亢layers of trout  Although a state of twisted without breaking the non- g was Li  Only to cowpea in the following figure around the hand of Saki珊  Become good long as )   This is not related to blockquoting since it does not matter that I am doing that. I know the issue is the less than symbol because it is immediately next to the alphabetical character W. I am assuming the renderer is seeing a partial html tag. If I put a number there or a space instead it is fine.   Likely this is a dupe but I didn't find what I was looking for outside of the following:    Which does not help since I am not working with backslashes.

I've posted a lot to StackOverflow, and I've noticed something kind of irritating with the formatting in writing questions and comments. If I need to put something inside a < and a >, without spaces in the middle (like right there), it will think it's code and not show up, like this   (obviously it won't come up what I wrote there, or else this wouldn't be an issue, but if you open up the question to edit you can see what's written there.)  If I want it to show up, right now I have to add an extra set of brackets inside of the originals with a junk variable, like right <here> (again, open in edit window to see).  This is really annoying when trying to show variables like lists that require those brackets, and I feel like the junk variables could confuse people looking at the edits. Is there a way to get around this formatting? Thanks!


I'm applying to the Austrian embassy for a multiple-entry Schengen visa. As per the checklist, they require "proof of onward travel in EU". Had a couple of questions regarding this:   Is this a mandatory requirement since pre-booking rail/bus bookings for travel out of Austria and then not obtaining a visa, would be wastage of money? Is there a way to reserve rail/bus tickets in a manner similar to reserving flight and hotel tickets before applying for a visa?   Thanks in advance!

The Schengen checklist for short stay when applying from South Africa via France includes this (emphasis mine):     "All transfers (flight/ferry/train/bus/taxi) showing entry & exit from   France and between other countries must be provided. Name of   applicant must appear on all proof of transport."   My flights are booked, I have proof of arrival from my country and a long series of flights to leave the schengen area and return home. There is a ferry into France and a flight from Berlin to Dublin (outside Schengen).  However, I prefer not to book some of my transport inside Europe because many train and bus systems do not allow me to book more than 90 days in advance (I am in the schengen area for 82 days). Is this something the visa people are likely to be difficult about, given that movement once one is inside the Schengen area is not supposed to be important?


I'm looking for a way to get the list of all my upvotes on Stack Overflow, however after looking through the , seems there is no way to achieve that.  And I know I can view my upvotes in votes tab, however I'm looking for an official API to query the list.

I'm looking to obtain a list of another user's posts that I have upvoted.  I learned in  that this is not possible through the Stack Exchange Data Explorer, because any private data, including up/down votes, are not included in the SEDE data dumps.  That left me wondering: Is such a list theoretically possible to obtain by writing my own app that uses the ?  If so, are there any apps that anyone has written that already do this?    I have seen this question:  However, that question appears to be asking if it is possible to view all users votes, as the OP wants to do some sort of study on different users' voting activity.  I realize that it would not be possible to see any users votes, as that is private information.  What I'm asking, however, is whether it would be possible to write an app using the API that would allow me to log in and view my own votes.  This would be similar to what is available on the website looking at my own profile, but because I'm writing my own app, I could potentially do more searching and present the data in a different way than what is available on my profile tab.  The answers on that other question do not explicitly answer this question.


Consider a measurable space $(\Omega,\mathcal{F})$. Is the supremum of an uncountable family of Borel measurable functions of the type $f:\Omega\to\mathbb{R}$ a Borel measurable function?

Show that the supremum of an uncountable family of $[-\infty, \infty]$- valued Borel measurable functions on $\mathbb{R}$ can fail to be Borel measurable.  Does this mean that I need to find some kind of family such that the intersection of the  sets $$\{x\in A | f_n(x) \leq t \}, $$ for all $t$, fails to be an Borel set? Or is there some easier way?


I tried the following command:  gsettings set org.gnome.gnome-screenshot auto-save-directory "file://$HOME/screenshots   And it didn't appear to do anything. gnome-screenshot seems to ignore this command and only use XDG_PICTURES_DIR to make decisions. I can set XDG_PICTURES_DIR to ~/screenshots, which I did and it works, but I would like to separate screenshots and pictures. Is there any way to do this?

I want to change the default location of "Save a screenshot to Pictures" to save it to Desktop.   If that is not possible, is there any other way to do it? I am using Ubuntu GNOME 17.04.  NOTE: I don't want to change the location with dconf-editor as it changes the location of screenshot applet and not of the shortcut I require.


I have Ubuntu installed on one partition of my computer and I'm trying to install Arch Linux on a second partition.  I'm having trouble with the bootable USB, so I'm trying to just install it after booting Ubuntu and I add the binary path to $PATH and the pacstrap command I need shows up when I use the which command, but it doesn't work when I try to run it.  I would just use ./pacstrap, but the it needs to be able to find other binaries that are in the same directory.  Is there a reason that the environment would be able to find a binary with 'which' but not when I execute it?  john@TheBrain:/storage/part4/Software/root.x86_64/bin$ export PATH john@TheBrain:/storage/part4/Software/root.x86_64/bin$ sudo pacstrap /mnt base base-devel sudo: pacstrap: command not found john@TheBrain:/storage/part4/Software/root.x86_64/bin$ which pacstrap /storage/part4/Software/root.x86_64/bin/pacstrap john@TheBrain:/storage/part4/Software/root.x86_64/bin$

As example to my question, my ~/.bashrc file contains this lines:  export LD_LIBRARY_PATH=/opt/intel/mkl/lib/ia32:$LD_LIBRARY_PATH export LD_PRELOAD=/opt/intel/mkl/lib/ia32/libmkl_core.so   so that Numpy (Python) could find libraries that it needs to run, as it's build with MKL and Intel compilers. This workflow isn't the best, but that's another story.  My question is how can I pass arbitrary variables (like those in ~/.bashrc) when I run program with 'sudo' (but not root)?  Currently, if I run:  sudo python -c "import numpy"   I get an error:  ImportError: libimf.so: cannot open shared object file: No such file or directory*   Some suggestions as sudo -i or sudo -E does not change anything here.    Edit:  I can't answer my question (not enough points :D ) but I'll comment here, in a hope that there are other Linux newbies wondering about sudo traps.  [Only temporarily!] This works for me (~/.bashrc):  alias sudo='sudo env PATH=$PATH VAR1=SOME_VALUE VAR2=SOME_VALUE...'


I just need advice on how I am going to optimize my database.  | Date | Time | Area | Block | Data1 | Data2 | Data3 | DataN |  I have that format of tables on my database. Each tables has 30-days of records with hundred thousands of records each data. Uploading of data to database is every morning. The data of yesterday will be uploaded.  The most common queries to run is grouped by Date or Date and Area or Date and Area and Block. Now, in order to make queries faster, I found out using indexes. I used indexes before. But that was when I am using a primary key. In this table, I didn't use primary key because it is totally unnecessary.  Now, I am really confused on how I am going to optimize this. Based on  on Column Considerations part, clustered index is not a good choice on Columns that undergo frequent changes. I am really confused.  Please help me if I need to use clustered index here or just non clustered or both.

I just need advice on how I am going to optimize my database.  Date ---- Time ---- Area ---- Block ---- Data1 ---- Data2 ---- Data3 ---- DataN   I have that format of tables on my database. Each tables has 30-days of records with hundred thousands of records each data. Uploading of data to database is every morning. The data of yesterday will be uploaded.  The most common queries to run is grouped by Date or Date and Area or Date and Area and Block. Now, in order to make queries faster, I found out using indexes. I used indexes before. But that was when I am using a primary key. In this table, I didn't use primary key because it is totally unnecessary.   Now, I am really confused on how I am going to optimize this. Based on  on Column Considerations part, clustered index is not a good choice on Columns that undergo frequent changes. I am really confused.  Please help me if I need to use clustered index here or just non clustered or both.


Are there any logical proofs that miracles are impossible?  In this case I define a miracle as an interference with nature by a supernatural power.  [Edit: Possibly due to confusion about the difference between "rationality" and "logic" someone marked this question as a duplicate. If you look at the supposed duplicate question ("What should a rational person accept as a miracle?", you can see that this is a very different question.]

I was reading  which was suggested to me in a response to . On p. 2, in an article entitled "Unlikely," Laurence M. Krauss, a professor of physics and astronomy at Case Western Reserve University, says:     "Of course, nothing would stop science from uncovering positive evidence of divine   guidance and purpose if it were attainable. For example, tomorrow night if we look up at the stars and they have been rearranged into a pattern that reads, “I am here,” I think even the most hard-nosed scientific skeptic would suspect something was up."   This, as I understood, means that for physicists, maybe, and only maybe a phenomenon like stars lining up in "I am here" fashion, can be regarded as a miracle. Then I thought: is there anything special in nature that can cause a rational person to think of that phenomenon as a miracle?   What should a rational person consider as constituting a miracle? For example, if someone appears now and brings dead people back to life, why should a rational person believe his/her action as a miracle? Maybe because he can't do the same, or because he knows that returning a dead person back to life is impossible, or maybe he/she doesn't accept that action as miracle.


What word or phrase could be used to accurately describe when someone has excellent or super-sensitive hearing far beyond that of most people, where they might have, for example:   the ability to hear in detail a much further distance, for example an approaching aircraft 10 seconds before anyone else can hear it; increased ability to differentiate and split sounds to identify and process them in parallel, for example listen to 5 or more different conversations at once in a noise room and be able to relay what was said later; the ability to hear a frequency and quickly identify it approximately; frustration that they always tune-in to constant or repeating background noises/sounds such as generated by electrical appliances, transformers, vibrations, ticking clocks, dripping taps, several rooms away, and even if so quiet no-one else can hear them or notice them except up close.

Often, when overheard from far away, I find myself saying/thinking:     [S]he has the ears of a hawk!   Which doesn't really make sense as hawks aren't particularly well known for their sense of hearing.  Is there a common saying, equivalent to "eyes of a hawk", relating to someone's sense of hearing?


My understanding is that "whether" reflects a choice between at least two alternatives, so is the usage in the following sentence correct? "A participant decides whether he wants to proceed to the next stage"    or do I have to explicitly state "or not" as in:    "A participant decides whether he wants to proceed to the next stage or not"

This will depend on whether he's suitable for the job.    This will depend on whether he's suitable for the job or not.   This will depend on whether or not he's suitable for the job.         It is still not defined whether we're following that approach.   It is still not defined whether we're following that approach or not.   It is still not defined whether or not we're following that approach.         "Or not" doesn't really seem to be needed to complement "whether". Why do people use it then? Is it redundancy and nothing more? Or is it for emphasis? Or are there cases when "or not" is required for the sentence to be grammatical?


I was going through a short tutorial on dimensionality reduction techniques. Some of these techniques are linear while others are non-linear. What is the distinction between them? Why the terms 'linear' and 'non-linear'?

I am trying to understand the differences between the linear dimensionality reduction methods (e.g., PCA) and the nonlinear ones (e.g., Isomap).  I cannot quite understand what the (non)linearity implies in this context. I read from  that     By comparison, if PCA (a linear dimensionality reduction algorithm) is   used to reduce this same dataset into two dimensions, the resulting   values are not so well organized. This demonstrates that the   high-dimensional vectors (each representing a letter 'A') that sample   this manifold vary in a non-linear manner.   What does     the high-dimensional vectors (each representing a letter 'A') that   sample this manifold vary in a non-linear manner.   mean? Or more broadly, how do I understand the (non)linearity in this context?


If Republic credits are no good, what is used for or what is money called on Tatooine? Water would be an obvious currency but some form of 'cash' is seen being used.

In APM and the Clone Wars series, among other media, there are frequent instances where Republic credits are not accepted. These are typically places outside of the Republic and especially in the criminal underworld, Republic or otherwise.  If Anakin wants to pay Hondo to deliver some missiles illegally and not ask any questions, and Hondo does not accept credits, then what does Anakin pay him off with?


I have a very basic android app that has 1 tab, with three sub sections on it. Section 1, 2, and 3. The code below tells the app to display "1", "2", or "3" in a string depending on which section is selected. I added an if statement to see if I could alter the output, but it appears to be ignoring the condition. When I debug the code using logcat it shows the value of dummyTextView is "1", but it does not step into the condition and change it to the "Peeshaw" line i created. Anyone know why this is happening?  @Override         public View onCreateView(LayoutInflater inflater, ViewGroup container,                 Bundle savedInstanceState) {             View rootView = inflater.inflate(R.layout.fragment_main_dummy,                     container, false);             TextView dummyTextView = (TextView) rootView                     .findViewById(R.id.section_label);             dummyTextView.setText(Integer.toString(getArguments().getInt(                     ARG_SECTION_NUMBER)));              if (dummyTextView.getText() == "1")             {                 dummyTextView.setText("Peeshaw");             }              if (dummyTextView.getText().toString() == "1")             {                 dummyTextView.setText("Peeshaw");             }              return rootView;         }

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?


How can I set a specific theme for a specific QT application? Globally I used a dark theme but for some applications I want to use the default theme of Ubuntu 16.04 (Ambiance). This is for a specific QT application.  I tried these commands inside my spreadsheet.desktop  Exec=env GTK2_RC_FILES=/usr/share/themes/Ambiance/gtk-2.0/gtkrc /usr/bin/et   or  Exec=env GTK2_RC_FILES=$HOME/.themes/Ambiance/gtk-2.0/gtkrc /usr/bin/et   or  Exec=env GTK_THEME=Ambiance:Default /usr/bin/et   But none worked.

I want to change the theme that Inkscape uses to a dark one, but I want the rest of the programs I use to retain the theme they currently have.  I found this article () but it seems to be outdated and doesn't work for me.  I'm running Ubuntu 13.10 and the version of inkscape I'm trying to apply a different theme to is 0.48.4. I can change the theme of inkscape by changing the global theme using unity tweak tool, but then all other programs change too.  Also, if there's any way to change the icon set for a specific application, I would like to do that as well.


SUBSYSTEMS=="usb", ATTRS{idProduct}=="1337", ACTION=="add", RUN+="/usr/local/bin/New.sh"   script:  #!/bin/sh  vlc v4l2:///dev/video0   udevadm test shows that it runs the script but nothing happens :/

What is the state-of-the-art method for automatically executing custom scripts upon USB device plug-in under current Linux distributions like Debian/CentOS/Fedora?  For example if you want to automatically mount/copy some files/umount a USB mass storage device based on its UUID (or device ID etc.).


With $X_1,X_2,..$ as a sequence of i.i.d variables with F as a distribution function and $M_n=max\{X_m:m<=n\}$ for $n=1,2,..$  To prove $P(M_n<=x)=F^n(x)$, I did the following:   a) $P(M_n<=x)=P(max(X_1,X_2,...X_n)<=x)=\prod_{i=1}^{n}P(X_i<=x)=P(X_1<=x)\cdot P(X_2<=x)\cdot\cdot\cdot P(X_n<=x)=F\cdot F \cdot F.. = [F(x)]^n= F^n(x)$  b) Given $ F(x)=1-x^{-α}$ for $x>=1, α > 0$. Need to prove that as n approaches infinity  $P(\frac{M_n}{n^{1/α}} <= y) -> exp(-y^{-α})$  I proved $P(\frac{M_n}{n^{1/α}} <= y)=P(M_n<=y \cdot n^{1/α})=(F(y \cdot n^{1/α}))^n=(1-\frac{1}{n \cdot y^α})^n -> e^{-y^{-α}}$ as n approaches $\infty$  Are proofs in a) and b) are done correctly?  Please let me know if something needs to be added to make it solid.  Thank you very much!

Let be $X_1,X_2,...,X_n$ be uniformly distributed random variables i.i.d.  a)  Find the cumulative function and the density of $m_n \text{ and } M_n$ , where $m_n=min(X_1,X_2,...,X_n)$ and $M_n=max(X_1,X_2,...,X_n)$.  b)  Let $Z_n=n(1-M_n)$. Show that $Z_n \xrightarrow{d} Z $, where $Z$ is a random variable with cumulative function $F_Z(z)=1-e^{-z}$


The closed form for this sum, $$\sum_{r=1}^{n} (2r) 3^{n-r}=\frac{1}{2} \left(-3 + 3^{1 + n} - 2 n\right)$$ is quoted in my textbook. How would I derive it?

How can I evaluate $$\sum_{n=1}^\infty\frac{2n}{3^{n+1}}$$? I know the answer thanks to , but I'm more concerned with how I can derive that answer. It cites tests to prove that it is convergent, but my class has never learned these before. So I feel that there must be a simpler method.  In general, how can I evaluate $$\sum_{n=0}^\infty (n+1)x^n?$$


I have a cloud server running Debian Wheezy.  Webserver is nginx.   If I go to www.mydomain.com in internet explorer I get my webserver just fine. However If I go to a command prompt on a remote machine and ping www.mydomain.com or domain.com I get request timed out.   This happens if I type the name of the domain or the ip.  Why is this? How can I enable ping requests on my linux box?  When i type   sudo iptables -L   The following is returned: -   Chain INPUT (policy ACCEPT) target     prot opt source               destination  Chain FORWARD (policy ACCEPT) target     prot opt source               destination  Chain OUTPUT (policy ACCEPT) target     prot opt source               destination   If I try to tracert to the domain the tracert goes through 8 hops, until it reaches my server IP then the server IP is displayed in tracrt and every other entry after that, reads "Request timed out".  Is there something I need to set in the Debian firewall to enable ping requests if so how do I do that?  Thank you.

I am not able to access my web server I recently set up on Ubuntu AWS EC2 instance:  client:~ user$ curl yyy.yyy.yyy.yyyy curl: (7) Failed to connect to yyy.yyy.yyy.yyyy port 80: Operation timed out   Apache is up and running at the AWS instance:  ubuntu@server:~$ sudo service apache2 status * apache2 is running   and the port 80 is opened   ubuntu@server:~$ sudo netstat -plunt | grep apache2 tcp6     0    0 :::80                 :::*                  LISTEN    2968/apache2    I am not that experienced in setting up web servers so far, but as I know Apache should be accessible right after it was installed. What might be wrong in my case?


That is, that the sum of two vectors is never longer than the sum of the lengths of the vectors.  It's easy to see this is true geometrically: if you attach the vectors head to tail, the longest they can be is if they are in the same direction. Alternatively, you can see the two vectors and their sum form a triangle, and the length of a side can never be longer than the sum of the other two sides (the longest it can be is a degenerate triangle, with angles 0-0-180).  How can we prove this with high-school algebra (i.e. [algebra-precalculus]), using vectors in component form, $\vec{a} = (r,s), \vec{b} = (p,q)$?  Note: the "duplicate" question does not request high-school algebra, and accepted an answer using the Cauchy–Schwarz inequality and vector dot product, which are not usually taught in high school at all.

Generally,the length of the sum of two vectors is not equal to the sum of their lengths. To see this consider the vectors $u$ and $v$ as shown below.  By considering $u$ and $v$ as two sides of a triangle, we can see that the lengths of the third side is $\| u + v \|$ and we have $\| u + v \| \leq \|u\| + \|v\|$.  Under what circumstance equality occurs and how can one prove that?


I'm learning Java. Now I'm trying to write the code that'll print out the GUI table. but the error message keeps showing java.lang.NullPointerException  Here's my main method  private JTable table; Products proarr[]=new Products[20]; public static void main(String[] args) {         EventQueue.invokeLater(new Runnable() {             public void run() {                 try {                     ProductForm frame = new ProductForm();                     frame.setVisible(true);                 } catch (Exception e) {                     e.printStackTrace();                 }             }         });     }    Here is my code for adding model to Jtable  public ProductForm() {         proarr[0]=new Products("Samsung", "Iron", "Yangon", 42, "info", 90, 20);//object array         proarr[1]=new Products("LG", "Fridge", "biege", 232, "info", 90, 25);         proarr[2]=new Products("LG", "Air-Con", "Yangon", 62, "info", 90, 10);         proarr[3]=new Products("Toshiba", "Hair dryer", "Yangon", 300, "info", 90, 35);         proarr[4]=new Products("Samsung", "Iron", "Yangon", 450, "info", 90, 5);           table = new JTable();         table.setModel(new DefaultTableModel(             new Object[][] {              },             new String[] {                 "brand name", "product type", "color", "price in $", "product information", "quantity", "discount in percent"             }         ));          DefaultTableModel model=(DefaultTableModel) table.getModel();         for (int i=0; i<proarr.length; i++)         {             String brandname=proarr[i].getBrandname();             String producttype=proarr[i].getProducttype();             String color=proarr[i].getColor();             String price=Integer.toString(proarr[i].getPrice());             String productinfo=proarr[i].getProductinfo();             String quantity=Integer.toString(proarr[i].getQuantity());             String discount=Integer.toString(proarr[i].getDiscount());             String []data=new String[] { brandname, producttype, color, price, productinfo, quantity, discount};             model.addRow(data);         }   and here's the error message  java.lang.NullPointerException     at waiyancompany.ProductForm.<init>(ProductForm.java:96)     at waiyancompany.ProductForm$1.run(ProductForm.java:36)     at java.awt.event.InvocationEvent.dispatch(Unknown Source)     at java.awt.EventQueue.dispatchEventImpl(Unknown Source)     at java.awt.EventQueue.access$500(Unknown Source)     at java.awt.EventQueue$3.run(Unknown Source)     at java.awt.EventQueue$3.run(Unknown Source)     at java.security.AccessController.doPrivileged(Native Method)     at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)     at java.awt.EventQueue.dispatchEvent(Unknown Source)     at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)     at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)     at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)     at java.awt.EventDispatchThread.run(Unknown Source)

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


I want to write a 'restricted map' (a map which is equal to another map but with a smaller domain), we show it by drawing a vertical line and a subscript but I don't know if it has a specific method when we use TeX, the method I used so far is  $f|_P:A\longrightarrow B$    or   $\nu|_P:A\longrightarrow B$   Which doesn't have a very beautiful result. If anyone knows the standard method of writing restricted maps I will be thankful to hear it.

I wonder how to typeset the restriction of a function to some subdomain, a la $f|_A$ or $f\restriction_A$ , but with the vertical bar being as big as possible.


Trying to install the .deb package from Teamviewer's website gives unmet dependencies on 64-bit architecture, because the downloaded file is for 32-bit architecture.

I was trying to install Teamviewer, but I was getting a dependency error. I tried to install the required packages, but with no luck.  I'm getting this error:  Unpacking teamviewer (from teamviewer_linux_x64.deb) ... dpkg: dependency problems prevent configuration of teamviewer:  teamviewer depends on lib32asound2; however:   Package lib32asound2 is not installed.  teamviewer depends on lib32z1; however:   Package lib32z1 is not installed.  teamviewer depends on ia32-libs; however:   Package ia32-libs is not installed.  dpkg: error processing teamviewer (--install):  dependency problems - leaving unconfigured Errors were encountered while processing:  teamviewer   I tried   sudo apt-get -f install   Getting   Package ia32-libs is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source However the following packages replace it:   lib32z1 lib32ncurses5 lib32bz2-1.0  Package lib32asound2 is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'lib32asound2' has no installation candidate E: Package 'ia32-libs' has no installation candidate   I can't even get to the   sudo dpkg -i teamviewer_linux_x64.deb   If I force installation  sudo dpkg --force-depends -i teamviewer_linux_x64.deb   Although it's "Setting up Temviewer" it gives me this:    How can I fix this problem?


I am using query function to copy all data from sheet1!A2:B10 to Sheet2 if B column is equal to specific data/time. Lets say A1 = 5 April 2021 A2:A10 names B2:B10 has Timestamp And I used this formula Query(sheet1!A2:B10," select * where B=A1+31/24",0) which means query all data if B = 6 April 2021 07:00 But query doesn't accept such format. Any thoughts? one Idea to create a column C where I put the date/time static (6 April 2021 07:00) and use query(sheet1!A2:C10,"select * where B=C",0) but seems I have to convert column C to text as well..

for a few days I'm stuck at comparing two dates.  In a big table with dates as columns and products as rows, we want to display the amount of sales per day per product.  What the following query does:   Import our sales via IMPORTRANGE query the specific sales for a given day and product ID return 0 if there is an error (e.g. not found) count the result   This is a working query with the date 2018-03-26 hard coded:  =COUNTA(IFERROR(query(IMPORTRANGE("1OHR0nr_w3oFNNxtMxRwv65xncCBRpK-vV3vvqmHGFPo"; "Sales March!A:K"); "select Col6 where Col6 = '"&$A95&"' and todate(Col11) = date '2018-03-26'"; 0)))  It shows how many sales a specific product has on the specified date.  Now I want the date from a cell in the sheet:  =COUNTA(IFERROR(query(IMPORTRANGE("1OHR0nr_w3oFNNxtMxRwv65xncCBRpK-vV3vvqmHGFPo"; "Sales March!A:K"); "select Col6 where Col6 = '"&$A95&"' and todate(Col11) = date '"&$AR3&"'"; 0)))  But this doesn't work. I tried A LOT of things for the past 3 days but I have no idea if I did that wrong (I'm a beginner) so I'm turning to you. What might be wrong with the date comparison in this section?  "select Col6 where Col6 = '"&$A95&"' and todate(Col11) = date '"&$AR3&"'"  You can see it  in Column AR Row 95 but I can't give edit rights.


I have an Indian passport and a B1/B2 US Visa and I am travelling to California.  While returning, my flight is via Dallas. Can I exit the Dallas airport on landing there and go through immigration again to catch my flight back to India?

My wife and I are flying to Iceland and we are trying to book tickets but I wasn't sure about the flights.  So I am just asking to clarify. If I leave the US through an airport, do I have to return to the US through the same airport?


i have a folder with tons of subfolders containing png's.  how can i step recursively through the subfolders and convert that files to pdf? The pdf should have the name of the subfolder and be saved in the starting folder ... there are no folders in folders, no problem with double names expected. i'm beginner, tried other ideas, but terrible things happend ...  joe

I have lots of large video files of my kids (.MTS format). Now I would like to convert them into divx / xvid to save hdd space and also have the ability to watch on my TV set.   Video files are stored in nested folders on my hdd (based on shooting times or special events). So, keeping the existing folder structure I would like to convert all the videos (which may take some days I believe) automatically.  I will appreciate if you can guide me how to achieve it?


The question is vague, and I apologize for that. I don't know how to make the dot that has the transform tools, appear in the middle of the mesh like it is supposed to be. I would appreciate some assistance with this.  the dot with the arrows below the object

So, I'm working creating a lamp... yes, newbie here.  After modeling for a bit, I noticed that my point of origin was no longer the center of my object:    How to I reset an object origin point to the center of it's geometry?


How do you pronounce the possessive form of Las Vegas?  Example: Las Vegas' best radio station  Is it correct to put only an apostrophe after the 's' when writing the possessive form of this noun?

Possible Duplicate:           My name is Greg — this is Greg 's post.  If my name ended with an 's', I am aware of the proper apostrophe usage (James → James'), but how should this be pronounced?  Phonetically, am I Jameses best friend or James best friend?


In integrals, we often make 'u' substitutions, which involve writing $u=f(x)$, and then also writing $du=f'(x)dx$. How valid is this? I've heard that you aren't allowed to do things like 'break' up derivatives like they do to solve first order differential equations. So can you do this with integrals, or is it also a mnemonic?

When you are doing an integration by substitution you do the following working. $$\begin{align*} u&=f(x)\\ \Rightarrow\frac{du}{dx}&=f^{\prime}(x)\\ \Rightarrow du&=f^{\prime}(x)dx&(1)\\ \Rightarrow dx&=\frac{du}{f^{\prime}(x)}\\ \end{align*}$$     My question is: what on earth is going on at line $(1)$?!?   This has been bugging me for, like, forever! You see, when I was taught this in my undergrad I was told something along the lines of the following:  You just treat $\frac{du}{dx}$ like a fraction. Similarly, when you are doing the chain rule $\frac{dy}{dx}=\frac{dy}{dv}\times\frac{dv}{dx}$ you "cancel" the $dv$ terms. They are just like fractions. However, never, ever say this to a pure mathematician.  Now, I am a pure mathematician. And quite frankly I don't care if people think of these as fractions or not. I know that they are not fractions (but rather is the limit of the difference fractions as the difference tends to zero). But I figure I should start caring now...So, more precisely,     $\frac{du}{dx}$ has a meaning, but so far as I know $du$ and $dx$ do not have a meaning. Therefore, why can we treat $\frac{du}{dx}$ as a fraction when we are doing integration by substitution? What is actually going on at line $(1)$?