I'm a new user to Ubuntu and Linux, and I'm trying to install Skype. The software manager is starting but then canceling without any report, I tried doing it through the terminal using:  echo "deb http://archive.canonical.com/ubuntu trusty partner" | sudo tee -a /etc/apt/sources.list.d/canonical_partner.list sudo apt-get update sudo apt-get install skype   And some other methods, but I always get the same error every time:  E: Unable to locate package skype   I checked the Canonical reps, and I really have no idea what am I doing wrong here?  I am using Ubuntu 16.04, and I just tried to follow various threads, but reached the same dead end.

I want to install Skype, but I can't locate it in Software Center or by using Synaptic Package Manager. Can anyone help me?


I just modified an answer and I can see that there are some missing highlights for the scheme language.  It's unclear what is not handled by the highlighter. But I'd say that the current functions are quite "standard" enough to get added to highlighting.   begin display newline set!

I noticed that sometimes my code gets highlighted in different colors when rendered.   What is syntax highlighting? How does it work? Why isn't my code being highlighted correctly? How do I report a bug or request a new language? How do I use syntax highlighting? What languages are currently available on Stack Exchange?


This question has the following hint:     Find a linear function $L(x,y)$ such that $f(x+h,y+k)-f(x,y)-L(h,k)=hk$. Note that $|hk|\leq l^2$ where $l:=max\{|h|,|k|\}$. Does this help you establish that a certain limit is zero? To establish that the limit is zero, provide an $\epsilon-\delta$ proof.   My initial post questioned the linear function part; hence the first couple comments. I'm now adding my proposed solution that I'd like to have critiqued.     Let $h,k\in\mathbb{R}$ such that $|hk|\leq l^2$ where $l:=\mbox{max}\{|h|,|k|\}$, and suppose $L(h,k)=kx+hy$. Thus,   $$\frac{|f(x+h,y+k)-f(x,y)-L(h,k)}{||(h,k)||}=\frac{|(x+h)(y+k)-xy-(kx+hy)|}{\sqrt{h^2+k^2}}=\frac{|hk|}{\sqrt{h^2+k^2}}.$$   Then, note that   $$|h|^2\leq h^2+k^2\Rightarrow|h|\leq\sqrt{h^2+k^2}\Rightarrow\frac{|h|}{\sqrt{h^2+k^2}}\leq1\Rightarrow\frac{|hk|}{\sqrt{h^2+k^2}}\leq|k|.$$   Hence,   $$\frac{|f(x+h,y+k)-f(x,y)-L(h,k)}{||(h,k)||}=\frac{|hk|}{\sqrt{h^2+k^2}}\leq|k|.$$   So,   $$\lim_{(h,k)\rightarrow(0,0)}\frac{|f(x+h,y+k)-f(x,y)-L(h,k)}{||(h,k)||}=0.$$   Therefore, by the definition of derivative, $f$ is differentiable everywhere.   It seems to me that an $\epsilon-\delta$ proof is unnecessary, but maybe I'm implicitly making an assumption that needs proved?

Let $f:\mathbb R^2\to \mathbb R$ defined by $f(x,y)=xy$. Prove $f$ is differentiable.  According to the definition I have to show this $$\frac{\|f((x_0,y_0)+(h_1,h_2)) - f(x_0,y_0)-T(h_1\space  h_2)\|}{\|(h_1,h_2)\|}\to 0$$  But I got stuck in the proof.  \begin{align} & \frac{\|f((x_0,y_0)+(h_1,h_2))-f(x_0,y_0)-T(h_1\space  h_2)\|}{\|(h_1,h_2\|} \\[10pt] = {} & \frac{\|(x_0+h_1)(y_0+h_2)-x_0y_0-(x,y)(h_1\space  h_2)\|}{\sqrt{h_1^2+h_2^2}} \\[10pt] \le {} &\frac{\|x_0h_2+y_0h_1+h_1h_2\|}{\sqrt{h_1^2+h_2^2}}+\frac{\|-(x,y)(h_1\space h_2)\|}{\sqrt{h_1^2+h_2^2}} \end{align} and I think I the first term after the inequality goes to zero, but what happen to the second term?  How can it goes to zero too?


I know that there are quite many questions about the prime ideals of $\Bbb Z[x]$ on MSE. Actually I meet an exercise on this (in the book "Algebra: Fields and Galois Theory" by Falko Lorenz, Exercise 5.12) and the author outline an approach as follows:  (a) For every prime number $p$ and every normalized (that is, "monic") $f$ $\in$ $\Bbb Z[x]$ whose image $\bar f$ is irreducible in $\Bbb F_p[x]$, the ideal ($p$, $f$) is a maximal ideal of $\Bbb Z[x]$. (b) If $P$ is a prime ideal of $\Bbb Z[x]$ that is not of the form given in (a), $P$ is a principal ideal of $\Bbb Z[x]$. If $P$ is a principal ideal of $\Bbb Z[x]$, then $P$ is not a maximal ideal.  I have done by myself (a). For (b), I reduce it into two cases depending on whether $P$ is principal. I also show that if $P$ is principal, then $P$ is not maximal. So where I get confused is the case when $P$ is not principal. I can't reach a contradiction if I further suppose $P$ is prime but not the one in (a). Any ideas or hints?

Let $\mathbb{Z}[X]$ be the ring of polynomials in one variable over $\Bbb Z$.  My question: Is every prime ideal of $\mathbb{Z}[X]$ one of following types? If yes, how would you prove this?  $(0)$.  $(f(X))$, where $f(X)$ is an irreducible polynomial.  $(p)$, where $p$ is a prime number.  $(p, f(X))$, where $p$ is a prime number and $f(X)$ is an irreducible polynomial modulo $p$.


I realize this is almost identical to  and , but I'm asking specifically about a command I can run in the Cygwin shell to use the current Windows UI application bound for the argument's extension, that as on OS X opens that application if necessary, and opens the specified file in that application.  The cmd.exe start command isn't an option in the Cygwin shell, nor are xdg-open or gnome-open available through Cygwin.  Is there an equivalent?

Is there an equivalent to OSX open command in cygwin. open opens a file with the default application for that type.  I want to do something like  $ magic-command file.xls #excel opens as if file.xls would have been double-clicked  $ magic-command file.txt #notepad opens as if file.txt would have been double-clicked   You get the idea?  Basically something like a "cygwin-double-click" command.


Since the T-800 was meant to be an infiltration unit, it doesn't make much sense for there to be multiples of the same face. But somehow at least five separate terminators from the movies are all replicas of Arnold (forgiving some aging from the actor)  Are there any hints at non-Arnold T-800 models or an explanation as to why all T-800s look the same?

In the original film, The Terminator, Schwarzenegger's character was a "Cyberdyne Systems Model 101". Likewise for Terminator 2 & 3.  However, in the video game adaptation of Terminator 3, this same cyborg is referred to as a T-800. Terminator: Salvation reused this same model name.  Was there ever an explanation as to how this paradox originated? Or was this just the most embarrassing fluke in film writing history?


It is difficult to get a man to understand something, when his salary depends upon his not understanding it -- Upton Sinclair  Why "... his not understanding it", and not "... him not understanding it"? I thought that the meaning was "... when his salary depends about (the man) not understanding (something)"

The rule says that we can use a possessive adjective or an object pronoun before a gerund. Is there a rule  that says when to use each or are they interchangeable? Some say that it's wrong to use an object pronoun before a gerund.


I installed MacTex 2014, and then LyX, but when I start LyX up all the document classes are unavailable. Reconfiguring does nothing. Do you have to add something to the path for LyX to know where to look?

For example, TeX Live Utility 1.17 and earlier will not work on Mac OS X 10.10 Yosemite. If a shell task relies on the PATH environment variable to launch a command, rather than a fully-specified path, it will likely fail. A typical error message will look like this:  /usr/texbin/updmap-sys: line 30: exec: updmap: not found   This can also occur in programs that launch pdflatex, dvipng, epstopdf, or other commands as part of a typesetting process.


I was in creative mode on Minecraft PE, and decided to build a really awesome house to live in.   After I was done with my house, I decided I would just explore for a bit. I didn't realize that I had walked too far from my house that I had completely lost it! It wasn't on a map, and I didn't keep track of which side of a compass it was on!   Is there any way to find my house again? I really need help trying to find my house again! Please help me find it!

I was in creative mode on minecraft PE. I made this really awesome house plus a hotel! I was finishing up my house but decided to explore first. I explored for about 10 minutes and then stopped. Suddenly, I started worrying because I didn't know where I was. I couldn't find my house on a map, a compass, and I didn't make a beacon or keep track of what side of the sun it was on either. How can I find my house again???


I've successfully changed the background image for OS X login screen, but cannot do it for the FileVault login screen.  This makes sense as the contents of the disk are still encrypted at that point in the boot process.  Per this link:  it appears possible, but I honestly cannot understand what they are suggesting here.  Any ideas or interpretations?

After turning on encryption with FileVault on my MacBook Air with Mountain Lion my login screen went gray. Is there a way to go back to the default one?  The grey one    The default one


The package system is broken      Check if you are using third party repositories. If so disable them, since they are a common source of problems.   Furthermore run the following command in a Terminal: apt-get install -f      The following packages have unmet dependencies:  libvlccore8: Depends: vlc-data (= 2.2.5.1~ppa) but 4.0.0~rc1~~git20180121+r73720+120~ubuntu16.04.1 is installed              Depends: libc6 (>= 2.15) but 2.23-0ubuntu10 is installed vlc: Depends: vlc-bin (= 4.0.0~rc1~~git20180121+r73720+120~ubuntu16.04.1) but it is not installed      Depends: vlc-plugin-base (= 4.0.0~rc1~~git20180121+r73720+120~ubuntu16.04.1) but 4.0.0~rc1~~git20180121+r73720+120~ubuntu16.04.1 is installed      Depends: vlc-plugin-qt (= 4.0.0~rc1~~git20180121+r73720+120~ubuntu16.04.1) but 4.0.0~rc1~~git20180121+r73720+120~ubuntu16.04.1 is installed      Depends: vlc-plugin-video-output (= 4.0.0~rc1~~git20180121+r73720+120~ubuntu16.04.1) but 4.0.0~rc1~~git20180121+r73720+120~ubuntu16.04.1 is installed    I cannot update or install anything. How can I solve this problem?

I just recently bought an arduino and requires gcc-avr/avrdude to compile the software. I installed avr for another microprocessor component a while ago but is obviously an outdated version (gcc version 3.3 20030512 (prerelease)) so I went ahead to update these but it didn't work.   (Please note that before hand I also broke my aptdaemon through an incomplete wine installation (couldn't get passed font installation agreement) but I fixed that via a re-installation then accepting the agreement.)   I am trying to update these by running  but the dependencies it requires cannot be installed due to avr... terminal reports   Reading package lists... Done Building dependency tree        Reading state information... Done build-essential is already the newest version. libncurses5-dev is already the newest version. libncurses5-dev set to manually installed. libusb-0.1-4 is already the newest version. libx11-dev is already the newest version. You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: arduino-core : Depends: gcc-avr but it is not going to be installed avr-libc : Depends: gcc-avr (>= 1:4.3.4) but it is not going to be installed Depends: binutils-avr (>= 2.20) but it is not going to be installed binutils-dev : Depends: binutils (= 2.21.0.20110327-2ubuntu3) but 2.21.0.20110327-2ubuntu2 is to be installed libcwidget-dev : Depends: libcwidget3 (= 0.5.16-3ubuntu2) but it is not going to be installed Depends: libsigc++-2.0-dev but it is not going to be installed Depends: libncursesw5-dev but it is not going to be installed libmpfr-dev : Depends: libgmp3-dev (>= 4.2.dfsg-1) but it is not going to be installed python-dev : Depends: python (= 2.7.1-0ubuntu5.1) but 2.7.1-0ubuntu5 is to be installed Depends: python2.7-dev (>= 2.7.1-1~) but it is not going to be installed tk8.4-dev : Depends: tk8.4 (= 8.4.19-4) but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).   But running   apt-get -f install   results in   (Reading database ... 163021 files and directories currently installed.) Unpacking binutils-avr (from .../binutils-avr_2.20.1-1ubuntu2_i386.deb) ... dpkg: error processing /var/cache/apt/archives/binutils-avr_2.20.1-1ubuntu2_i386.deb (--unpack): trying to overwrite '/usr/bin/avr-size', which is also in package avr-binutils 2.13.90.030512-2 dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Unpacking gcc-avr (from .../gcc-avr_1%3a4.3.5-1_i386.deb) ... dpkg: error processing /var/cache/apt/archives/gcc-avr_1%3a4.3.5-1_i386.deb (--unpack): trying to overwrite '/usr/bin/avr-g++', which is also in package avr-gcc-c++ 3.2.90.20030512-2 dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Errors were encountered while processing: /var/cache/apt/archives/binutils-avr_2.20.1-1ubuntu2_i386.deb /var/cache/apt/archives/gcc-avr_1%3a4.3.5-1_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1)   I have tried running update manager and updating my system via it but all I get is an error message  The following packages have unmet dependencies: arduino-core: Depends: gcc-avr but it is not installed avr-libc: Depends: gcc-avr (>= 1:4.3.4) but it is not installed Depends: binutils-avr (>= 2.20) but it is not installed   which then tells me to try running apt-get -f install which just results the same as last time.  So how can I fix my system, I really need the new avr, please :) BTW, my system is Ubuntu 11.04


I have a computer with the following spec: Intel(R) Core(TM) i7-3632QM COU @ 2.20 GHZ Ram 8 GB x64  I also have a SSD disk running on my Dell Vostro, does that need something extra?  Thanks!

For a given hardware configuration, how do I find out if Ubuntu will run on it? What considerations should I take into account when choosing an Ubuntu version and  such as:    with a lighter desktop than the usual Gnome and Unity  with the even lighter LXDE desktop   Obviously Ubuntu does not run on some processor architectures. So how do I go about choosing the right version and derivate. How can I find out the minmal system requirements?


I want to add stack flair in my WordPress site. How can I use that?  My site is .  I want to put it in the right column.  How can it be achieved?

Has anyone successfully embedded their  on a WordPress.com-hosted blog?  The free hosted version of  (not )  from all posts before publishing. So they to strip out just about anything I can add to embed my Stack Overflow flair.  Note: I'll be switching to a paid, hosted site in the future (fixing the problem), but I'm looking for a quick, short-term solution.


I want to disable automatic reboots in my windows operating system as it disrupts commands and sometimes even creates problem in programming

Windows 10 lets you 'schedule' a reboot for later. I want to disable it.  Evidently Windows scheduled itself for a reboot last night when I wasn't looking and just closed everything I had been working on the night before.  I reboot on the regular; I don't need Windows to do that for me.  Can I disable it completely? I don't mind if it downloads everything, and then says "hey, you should reboot," but it should never reboot itself, ever.  I'm using the "Pro" edition of Windows 10.


If $-1\le f(x) \le 1$, then $-1\le (f(x))^3 \le 1$ (I think, I am not sure what changes cubing will bring because it is <1) So the maximum value of $\int _0^1 (f(x))^3$ should also be 1, but that is not the right answer I have no other way to think on this. How to solve it properly?

Find the maximum value of $\int_0^1 f^3(x)dx$ given that $-1 \le f(x) \le 1$ and $\int_0^1 f(x)dx = 0$   I could not find a way to solve this problem. I tried to use the cauchy-schwarz inequality but could not proceed further  $$\int_0^1 f(x) \cdot f^2(x) dx \le \sqrt{\left(\int_0^1f^4(x)dx\right) \left( \int_0^1 f^2(x) dx\right)}$$  Any hints/solutions are appreciated.


I'm getting a lot of hits on my server. This server normally gets little to no traffic yet there's is constant hits every time I bring the server back up. I get the following error first   ip_conntrack: table full, dropping packet  then sooner or later my httpd runs out of memory and my server becomes unresponsive. Any ideas on how to fix it?   latest head of my access_log. I changed http to hxxp   122.193.164.5 - - [27/Mar/2011:23:48:35 -0700] "GET hxxp://pubs.acs.org/templates/jsp/_style2/_achs/css/atypon-main.css HTTP/1.0" 200 174299 "hxxp://pubs.acs.org/doi/abs/10.1021/ac100095u" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)"    218.29.188.217 - - [27/Mar/2011:23:48:38 -0700] "GET hxxp://rotator.adjuggler.com/servlet/ajrotator/913831/0/vh?ajecscp=1301294917498&z=pdn&dim=753179&kw=&click=, HTTP/1.0" 200 1181 "" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040206 Firefox/0.8"    117.41.182.55 - - [27/Mar/2011:23:48:38 -0700] "GET hxxp://www5.tellgames.com/media/games/images/tellgames/120x90/02470dca7676598b9381e4c5dc2eef05.jpg HTTP/1.0" 200 4883 "" "Mozilla/4.0 (compatible; MSIE 4.01; Windows 95)"    117.41.186.191 - - [27/Mar/2011:23:48:37 -0700] "GET hxxp://s0.2mdn.net/1361550/K2147_NBRD_FYEA_728.jpg HTTP/1.0" 200 41371 "hxxp://ad.doubleclick.net/adi/N3340.161249.ADNETIK.COM/B5252096.3;sz=728x90;click=" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040614 Firefox/0.9"    173.252.208.155 - - [27/Mar/2011:23:48:38 -0700] "GET hxxp://ads.smowtion.com/st?ad_size=160x600&section=1739112 HTTP/1.0" 200 1336 "hxxp://www.consumerhealthdigest.info/category/health-information" "Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.4) Gecko/20030701"    61.139.105.162 - - [27/Mar/2011:23:48:38 -0700] "GET hxxp://therugged.com/wp-content/uploads/2011/01/Steph61-80x53.jpg HTTP/1.0" 200 2980 "hxxp://www.therugged.com/category/lifestyle#player" "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.0.1) Gecko/2008070206 Firefox/3.0.1"

This is a  about DoS and DDoS mitigation.   I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth.  Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too!  This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own.  Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case.  It also goes away after a few hours.  Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening?  Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed.  As soon as I started it up again, this happened again and it crashed again.  How is that similar, and what can I do about it?


I just did the Eltry quest and ended up with the corrupt guards trying to take me in. I killed them as well as the other guards who tried to jail me when I walked out. I also killed the ones in the guard tower and now I have a 13,000 gold bounty on me in the reach right now. If I take the city with the Stormcloaks, does my bounty get reset to 0?

Is it possible to kill all of the guards in a town?  Ideally, I'd like to do this secretly so the entire town doesn't see my deeds and put a bounty on my head.  Edit: I was questing in Markarth and was told by a guard to back off and stop being nosy. I didn't and when I went to the Shrine of Talos I was set upon by a bunch of guards.  Now I have a huge bounty and I had to sneak/kill my way out of the city.  Every time I killed a group of guards the bounty was reduced by $1000, but I still have a $30,000 bounty.  I haven't even been through 1/3 of the city yet and know there has to be a lot of quests, so what do I do?  The only solution seems to kill every single guard (and inhabitant).


When writing C++ code, what is the difference between using class and struct?  class Foo final { };   vs.  struct Bar final { };   When should I prefer one over the other?  Is this merely a choice of programming/coding style?

This question was .  Now I'd like to learn the differences between a struct and a class in C++. Please discuss the technical differences as well as reasons for choosing one or the other in OO design.  I'll start with an obvious difference:   If you don't specify public: or private:, members of a struct are public by default; members of a class are private by default.   I'm sure there are other differences to be found in the obscure corners of the C++ specification.


Using: XeTeX 3.1415926-2.5-0.9999.3 (TexLive 2013) on openSuse 13.1  Setting up a multilingual buddhist glossary I have encountered the problem that closing (German) typographical quotation marks “ are being moved to the right with a space inserted. Additionally -- is no longer converter to ndash. (I have played around with removing certain packages, various fonts or \XeTeXlinebreaklocale to no avail.)  Kindly enough the documentation for xeCJK is Chinese only (/usr/local/texlive/2013/texmf-dist/doc/xelatex/xecjk/xeCJK.pdf apologies, I only read Japanese). The XeTeX main doc (xetex-languages.tex,v: 2.02  2009/06/15) does explain the package somewhat (ch. 3.4.1, p. 79), although some options do through errors. What vexes me a bit is the concluding paragraph:      3.4.2.3 Compatibility   eoretically, zhspacing should be compatible with all macro packages, except those who change the   definition of \hskip and \penalty, in which case special treatment should be applied. I haven’t found   any conflict when using common packages such as hyperref and fancyhdr. However, ulem redefineds   \hskip and \penalty, and causes unexpected output. Use zhulem provided along with zhspacing   instead.   Back to the problem:   Code (Lao, khmer, and birman omitted for this example)  \documentclass[10pt,a5paper]{book} \usepackage[inner=2cm,outer=3cm,top=2cm,bottom=4cm]{geometry} \usepackage{layout} \usepackage[CJKnumber]{xeCJK}   \setCJKmainfont{Bitstream CyberCJK}   \punctstyle{plain} \usepackage[babelshorthands]{polyglossia} \setmainlanguage{german}  \setotherlanguage{sanskrit}  \setotherlanguage{english} \setotherlanguage[numerals=thai]{thai}     \newfontfamily\thaifont[Script=Thai]{FreeSerif}     \XeTeXlinebreaklocale ’th_TH’    \usepackage{setspace} \usepackage{xspace} \usepackage{textcomp} \usepackage[hyphens,obeyspaces,spaces]{url}          \usepackage[colorlinks,filecolor=black,linkcolor=black,citecolor=black,urlcolor=black,breaklinks]{hyperref} \usepackage{color} \usepackage{wrapfig} \usepackage{microtype} \widowpenalty=10000 \clubpenalty=10000 \flushbottom % +++ Fonts  % using the Free-family Fonts saves UTF-8 hassles as most characters (e.g ā) are included. The following NOT pertinent for example, just layout  \setmainfont{FreeSerif}  \setsansfont{FreeSans}  \defaultfontfeatures{Ligatures=TeX}  \renewcommand{\headrulewidth}{0pt}  \renewcommand{\footrulewidth}{0pt}  \fancyfoot[LO,RE]{\bfseries\thepage}  \usepackage[compact]{titlesec}   \usepackage[font=footnotesize]{caption}   \usepackage{enumitem} % Zeilenabstand Listen  \setlist[itemize]{itemsep=-3pt}  \setlist[description]{itemsep=-3pt}  \setlist[enumerate]{itemsep=-3pt}  \setlength{\leftmargini}{1em}    \begin{document}   \begin{description}  % Some CJK and "--" here   \item[Āgama] ({\scriptsize ch./jap.:} 阿含經.) Das chinesische Analogon der Texte des Pāli-Kanons. Die Übersetzungen, meist aus dem Sanskrit, basieren auf teilweise älteren Texten als denen der Theravadins. Quellenangaben üblicherweise aus den ersten beiden Bänden (Nr. 1--155) des 大正新修大蔵経 \textit{Taishō shinshū daizōkyō;} Tōkyō 1922--32  % some "shifted" “ in this \item[Ariya pugalla.] A) Ein Erleuchteter, im modernen Thailand als buddhistischer „Heiliger“ Verehrter. („Erleuchtung“ wird einem Mönch üblicherweise erst nach seinem Tode nachgesagt. Von sich selbst zu behaupten, man besäße mehr übernatürliche Kräfte als man tatsächlich hat wäre für einen Ordinierten ein \textit{Pārājikā}-Vergehen.) % some Thai, lao etc, to add more confusion  \item[Jātaka(m) (Wiedergeburtsgeschichten).] (\textthai{ชาดก}, \textit{chadok}, {\scriptsize Skt.:} जातक, {\scriptsize Birm.:} ဇာတ်တော်; {\scriptsize Khmer:} ជាតក, \textit{cietɑk;} {\scriptsize Lao:} (\textlao{ຊາດົກ}, \textit{sadok,} {\scriptsize Jap.:} 本生) \end{description}  \end{document}       Any suggestions? a) What might cause it or b) workaround?

Neither a question nor really a complain, but I find I cannot use xeCJK in multilingual documents (in the present case French + English + Chinese), simply because it messes with the punctuation in the non-Chinese parts. It will, for instance, change "this… that" to "this…that" and "this, that" to "this , that", which is inconvenient. Too bad because the package is otherwise very nice.  Here's a minimal example showing the problem:     \documentclass {memoir} \usepackage{polyglossia} \usepackage{xeCJK}  \setmainlanguage{french}  \usepackage{fontspec}  \setmainfont{TeX Gyre Pagella}  \setCJKmainfont {STSong}  \begin{document}  This… that This, that  \end{document}   The output is the following:    The "this , that" problem appears strictly when I set the main language to French, not if I set it to English. The "this…that" problem appears irrespective of whether the main language is French or English.  And, by the way, forgive me if that's the wrong place to draw attention to this, but the package author's email address doesn't appear in the documentation and I just chanced on this site


I want to extract first 3 letters of the sentence which start with M and are followed by 2 digits.   If sentence is M30 INTHE SKY then output should be M30. IF sentence is THE INTHE SKY then answer should be np.nan(i.e. false as it didnot start with M)

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


Why do professors take on service duties, such as reviewing papers for a journal, or sitting on university committees?  What benefit does this have to their careers?  I can't imagine they enjoy reviewing papers, at least not more than all the other things they need to fit into their busy schedule.

At a recent seminar talk, I was amazed to note that one of the two coauthors (not the presenter) was the , since I had always assumed that taking on such a position would necessarily mean the end of a research career.    Are there m/any examples of people that continue to do substantial amounts of research when in a senior administrative position, such as dean, provost, president, etc.?  Do research faculty often become deans, presidents, etc.? Why do faculty usually do this? (I understand that there might be a pay increase, but does it usually indicate that they no longer want to do research as intensely?)


Is there any kind of rule that the first greeting to a person should be 'good morning' irrespective of the time you meet that person. Whether its afternoon or evening. Please clarify with with facts and proof.

Is it true that regardless of the time of the day, the first wish to a person must be Good morning? Even if I meet him in the afternoon?


I want to show that if $K$ is a field then $K[x]$ is principal  Here is what I did:  I took 2 polynomial p(x) and q(x). Since we're on a field we can do a euclidean division of polynomials:  $q(x) = p(x)a(x) + r(x)$ with $deg(r) < deg(p)$  Now if $r= 0$ we obviously have $p \in (q)$   But I don't know how to show that it is principal if $r \neq 0$  Also I would like to show that the assertion is false if we replace "$K$ is a field" by "$K$ is a principal domain and an integral domain". I can't figure out how to do that

A commutative ring $F$ is a field iff $F[x]$ is a Principal Ideal Domain.  I have done the part that if $F$ is a field then $F[x]$ is a PID using the division algorithm and contradicting the minimality of degree of a polynomial.  But I am facing difficulty to do the other part.


TL;DR: read only bold text + check pictures.   I was trying to change .txt files default program to visual studio code, the problem is, that when I open settings in windows 10 and try to change it there, visual studio code is not listed in the default programs and there is no browse button, so that I could pick any program I want via the path to it.     I have also tried to change the default app in right MB -> open with -> choose another app, but no luck, there was no permanent option.      How are you supposed to change the default program than?

I just installed Visual Studio Code 1.28.1, but I'm unable to associate it with the .txt extension on Windows 10.  I'm well aware how to associate an extension with an application on Windows. I can right-click in Explorer, select, "Open As...", select the application, and make sure "Always open with this app" is checked. Or I can go in to the properties of a file in Explorer, look at "Opens with", and click on "Change". Or I can go to "Choose default apps by file type …", etc. The problem is that none of this is working with VS Code.  Currently my .txt files are associated with EmEditor. I change the association to Notepad. No problem. I change the association back to EmEditor. That works.  But if I select the blue "Visual Studio Code" option that appears in the list of applications, nothing changes. The old association remains.  I even tried ignoring the blue icon in the selection list, and manually browsed and selected %LocalAppData%\Programs\Microsoft VS Code\Code.exe as the default editor. That doesn't work, either. Nor did manually selecting %LocalAppData%\Programs\Microsoft VS Code\bin\code.cmd.  In case you think this might be related to EmEditor, I tried to associate .tidyconfig files (which on my system are currently not associated with any editor at all) with VS Code. It did nothing.  What's going on? Associating VS Code with my text files should be the most basic of basic Windows integration. Why won't it work?  (I filed this as , but I had no responses. I'm filing it here in case the "bug" is some sort of user error.)


Do US citizens need a China transit visa to travel with two stops, in Chengdu (2.5-hour transit) and Jinan (2.15-hour transit)?

I'm transiting through China in Kunming, China.  I'm a South African national and do NOT fall under the 72-hour visa free program. However on [their official (travelchina) website][1] it says:     Nationals of most countries are eligible for the 24-hour direct   transit, while a visa is needed for the passengers transiting on   Afghanistan, Azerbaijan, Iran, Iraq, Kazakhstan, Kyrgyzstan, Malaysia,   Nigeria, Oman, Pakistan, Saudi Arabia, Sri Lanka, Thailand, Turkey,   United Arab Emirates and Yemen passports.   I'm sorry if I'm missing this, but the above is rather badly worded for me does "nationals of most countries" include ALL countries except those mentioned in the list shown?  Also again sorry if I'm missing this but again it is rather badly worded for me. I will fly via Thailand to China and then via China to Canada with an 8-hour layover in China. I see Thailand is mentioned on the list. I have a Thailand residency permit where I currently reside... Would that affect me at all?  Also, any idea if I can exit the airport in China and come back under the 24-hour visa exemption (should I be exempt)?  Many thanks.


In the context of:  and:  how can I force logout of a specific user through the console or terminal using either systemd or systemctl?  Even ending a users terminal session.  Assuming sudo access is granted. I specify systemd or systemctl, or similar, because, at least on Ubuntu, there are artifacts which remain when simply clicking "logout" through the GUI.  And, would want to be able to do this from a different account.

I chose an Openbox DE at the time of login and the system took ages to load the DE. So I switched to CLI (Ctrl+Alt+F1) and rebooted my system (but I wanted to logout from the GUI and not restart the whole system).   My question is, can I issue some command at CLI to log me out from the GUI so that I can select different DE. (I don't want to restart my system every-time DE hangs.)    $ DISPLAY=:0 gnome-session-quit --force  ** (gnome-session-quit:3144): WARNING **: Failed to call logout: The name org.gnome.SessionManager was not provided by any .service files


Does anybody know a method to solve the following problem numerically (or analytically, if there is a general method, but I doubt it).  I am given a matrix $A \in \mathbb{C}^{n \times n}$ and I want to minimize  $||A- \sum_{i=1}^{n}\lambda_i C_i||$ in the Frobenius-norm for given $C_i$ and unknown $\lambda_i \ge 0$ with $\sum_{i=1}^{n} \lambda_i =1$ and $\langle C_i,C_j \rangle = \delta_{i,j}.$  By compactness of the possible set of $\lambda_i$ the problem has always an actual minimum and also the convexity (since we are taking convex combinations of the $\lambda_i$) could be useful if we want to find a numerical algorithm.   But I am not very familiar with these kind of optimisation questions, so I would love to hear about possible algorithms to tackle this problem.

Let $\mathbf{x}=[x_1,\ldots,x_K]$. I have the following optimization problem:  \begin{array}{rl}  \min \limits_{\mathbf{x}} & \| \mathbf{Ax}-\mathbf{b} \|^2 \\ \mbox{s.t.} &  x_k\ge 0, \forall k \end{array}  Please I need your help to solve this problem.  Another thing: my main problem was  \begin{array}{rl}  \min \limits_{\mathbf{x}} & \| \mathbf{A'x}-\mathbf{b'} \|^2 \\ \mbox{s.t.} &  x_k\ge 0, \forall k &  \\ & \mathbf{x}^T \mathbf{1}=1  \end{array} Then I transformed it to the first problem by including the equality constraint in the objective function. Is it fine  to do so ?


Given that the Fibonacci number is 165580141 Is it possible to find $n$ using the closed form. I tried simplifying the closed form but I get stuck at:  $\sqrt5F_n = (\frac{(1+\sqrt5}{2})^n - (\frac{(1+\sqrt5}{2})^n$  $\sqrt5(165580141) + (\frac{(1+\sqrt5}{2})^n = (\frac{(1+\sqrt5}{2})^n$  ($370248451 + (\frac{1+\sqrt5}{2})^n)^{1/n} = \frac{(1+\sqrt5)}{2}$  I don't know how to proceed further.

Given only $F_n$, that is the $n$th term of the Fibonacci sequence, how can you tell if $n \equiv 1 \mod 2$ or $n \equiv 0 \mod 2$?  I know you can use the Pisano period, however if  $n \equiv 1$ or $n \equiv 2$ $\mod \pi(k)$, it can never be found, where $k$ is in $\pi(k)$ (The Pisano period).  Also there is the fact that if $\sqrt{5F_n^2+ 4}$ is an integer then $n  \equiv 0 \mod 2$, but is there a faster way?  Lastly, because $F_1 = F_2 = 1$, that would have to be an exception for whatever rule/formula that would apply.


Read it as a child in the mid 80’s in Hebrew.  A young man, the child of a planet’s ruler escapes in a small craft, possibly with his traitorous uncle and love interest.  Escape has something to do with conquest, rebellion and empire?  In the end discovers the rebel base on his home planet.  Spaceship guns and hand weapons were probably a translation to Hebrew of blasters.  The ruler’s title was an odd one: probably plutocrat.   Craft was detailed to have a bridge and one other room to show it’s small.   There was also a discussion of rations available in it.  Unlikely to be an obscure text, as it was translated.

I recall Asimov had a character who was The autoc of , clearly based on the word “autokrat” but I don’t recall the exact spelling.  This stumped Google, which would rather correct the spelling to some other word than find a unique word.  In the story, he had gone undercover and the reader did not know either that some other character was in fact the Autoc, until it had been revealed to the main character.


I have an IP address in the following format: 2a11:11a1:a11a:1111:a111:11a1:1111:1aa1 I need to get all the digits back from an IP format like this and have written the following:             var ipAddress = "2a11:11a1:a11a:1111:a111:11a1:1111:1aa1";             string result = "";             foreach (char c in ipAddress)             {                 if (!Char.IsDigit(c))                 {                     break;                 }                 result += c;             }              return result;   I would expect this to return "21111111..." etc but instead it just returns "2" ? Where am I going wrong?

In a C# (feel free to answer for other languages) loop, what's the difference between break and continue as a means to leave the structure of the loop, and go to the next iteration?  Example:  foreach (DataRow row in myTable.Rows) {     if (someConditionEvalsToTrue)     {         break; //what's the difference between this and continue ?         //continue;     } }


I made a large batch of strawberry rhubarb pie filling and apple pie filling.  How long can it sit out on the counter and at what temperature has it spoiled?

If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more?


On Linux systems, I have a file I want to preserve from (even accidental) deletion. How can I create a file even the root user can't delete?  For instance, by trying:  # touch file # chmod 000 file # chown <somebody>:<somebody> file # rm file   root user is able to delete the file (through the last command).  How can I avoid root user to (even temporary) delete the file?

Normal users can chmod files to make them unaccessible like  evgeniy@ubuntu:~$ touch test evgeniy@ubuntu:~$ chmod 444 test evgeniy@ubuntu:~$ echo 'test' > test bash: test: Permission denied   Can something like this be simulated for the root user?


I saw this thread:    You are using CI and unit tests, right?  Do you do anything more before pushing out new releases?  What kind of guidelines do you follow when writing unit tests?   Basically, I'm wondering how you make sure that each release is good enough.

Stack Exchange is my role-model for application development.  I've tried to learn as much as possible from the blog and podcasts, from thought process to design, architecture, convention, etc etc.  I'm just about to wrap my head around TDD and am curious about how the SE team approaches it.  Is there a methodology that all team members follow, or is it more developer-driven testing where you pick complex bits to unit test as needed, or is it more about catch-all integration testing once a piece of functionality is done, or... ?  Any input would be fantastic.


What is the temperature of air in the upper part of our atmosphere?  I read somewhere that it is of the order of 1000 K, but then, why is it cold there?  My question is different from the aforementioned question because it considers the outer atmosphere, and the various interactions occuring there, something which is completely out of context in the other question.

Why there is always cold at high altitudes. e.g. at peak of mountains. Also as we go high from sea level, temperature starts decreasing. Why is it?


if there are two graph $G$ and $H$ that have same number of vertices, and their degree sequences are the same. Does this mean that they are isomorphic ?

I need a pair of non-isomorphic graphs with the smallest n-vertex possibility and where degree sequences are the same. Is the minimum number 2, such as a multigraph with n=2? Please help with the reasoning on this question. Thank you!


Let $N\gg 1$ be a large parameter, which I ultimately want to let tend to infinity. I am reading an old  of Bourgain, where he claims the lower bound (Equation 2.50, pg. 118)  $$\sum_{q=1}^{N^{1/2}-1}\sum_{{1\leq a < q}\atop{(a,q)=1}}\frac{N^{3}}{q^{2}}\geq c(\log N)N^{3}, \tag{1}$$  where $(a,q)$ denotes the GCD of $a$ and $q$ and $c>0$ is some absolute constant, the value of which I don't care and may change from line to line.  Using the following  for Euler's totient function $\varphi(n)$  $$\varphi(n)>\frac{n}{e^{\gamma}\log\log n + \frac{3}{\log\log n}} \tag{2}$$  and the PNT, I only know how to show that  \begin{align*} \sum_{q=1}^{N^{1/2}-1}\sum_{{1\leq a < q}\atop{(a,q)=1}}\frac{N^{3}}{q^{2}}&\geq c\sum_{{1\leq q<N^{1/2}-1}\atop{q=\mathrm{prime}}}\frac{N^{3}}{q^{2}}\cdot q\\ &+c\sum_{{1\ll q<N^{1/2}-1}\atop{q\neq\mathrm{prime}}}\frac{N^{3}}{q^{2}}\cdot\frac{q}{e^{\gamma}\log\log q+\frac{3}{\log\log q}}\\ &\geq cN^{3}\log\log N \tag{3} \end{align*}  If I knew the asymptotics of the series $\sum_{q=1}^{N^{1/2}-1}\frac{\varphi(q)}{q^{2}}$ or $\sum_{q=1}^{N^{1/2}-1}\frac{1}{\sigma(q)}$, where $\sigma$ is the divisor sum function, then my problem would be solved. However, I have been unable to find such information.    John M. has very kindly provided me with the necessary asymptotics. To see how to get that formula, first recall that $\varphi(n)=\sum_{d\mid n}\mu(d)\frac{n}{d}$, where $\mu$ is the Mobius function, and $\sum_{n=1}^{\infty}\frac{\mu(n)}{n^{2}}=\frac{6}{\pi^{2}}$. Then  $$\sum_{n\leq x}\frac{\varphi(n)}{n^{2}}=\sum_{n\leq x}\frac{1}{n^{2}}\sum_{d\mid n}\mu(d)\frac{n}{d}=\sum_{{q,d}\atop{qd\leq x}}\frac{\mu(d)}{d^{2}q}=\sum_{d\leq x}\frac{\mu(d)}{d^{2}}\sum_{q\leq\frac{x}{d}}\frac{1}{q} \tag{4}$$  Using the formula $$\sum_{q\leq k}\frac{1}{k}=\log(k)+\gamma+\epsilon_{k},$$ where $\epsilon_{k}\sim\frac{1}{k}$, and $|\log(y)-\log([y])|=O(1/y)$, we see that  \begin{align*} \mathrm{(4)}&=\sum_{d\leq x}\frac{\mu(d)}{d^{2}}[\log(x)-\log(d)+\gamma+O(\frac{1}{x/d})]\\ &=(\log(x)+\gamma)(\frac{6}{\pi^{2}}-\sum_{d>x}\frac{1}{d^{2}})-\sum_{d=1}^{\infty}\frac{\mu(d)\log(d)}{d^{2}}+\sum_{d>x}\frac{\mu(d)\log(d)}{d^{2}}+O(\frac{\log x}{x})\\ &=\frac{6}{\pi^{2}}(\log(x)+\gamma)-A+O(\frac{\log x}{x}) \end{align*}

Does there exist a positive real number $C$ and a positive integer $M$ such that for all $n > M$ we have: $$\sum_{i=1}^n\sum_{j=1}^n\gcd (i, j)\ge Cn^2 \log n$$  This originally appeared as an Olympiad problem in the case of $4n^2$ on the RHS. This case was much simpler; simply let $i$ only range on primes values and one quickly derives a $\omega \left ( n^2 \log \log \frac{n}{\log n} \right )$ bound if I didn't mess up. The motivation for above bound is derived from the fact that $$\sum_{j=1}^n \gcd(i,j) \approx \frac{n}{i} \sum_{d|i} \varphi(i/d) \cdot d \approx n \cdot \tau(i) \cdot \frac{6}{\pi^2}$$ So we have: $$\sum_{i=1}^n\sum_{j=1}^n\gcd (i, j) \approx \frac{6n^2}{\pi^2} \sum_{i=1}^n \frac{1}{i} \approx \frac{6}{\pi^2} n^2 \log n$$  However, this is pretty unrigorous  reasoning. Does anybody have any ideas as to how to rigorously prove this bound? Of course, showing that the sum in fact gets "close" to $\frac{6}{\pi^2} n^2 \log n$ as $n \to \infty$ would be even better.


When I try and run the program this is what the computer returns:  First_Name    Last_Name   Test1       Test2       Test3       Test4       Test5       Average     Grade Exception in thread "main" java.lang.NullPointerException     at tests.Tests.main(Tests.java:132) C:\Users\Michael Jr\AppData\Local\NetBeans\Cache\8.1\executor-snippets\run.xml:53: Java returned: 1 BUILD FAILED (total time: 0 seconds)  package tests; import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.text.DecimalFormat; import java.util.ArrayList; import java.util.List; /**  *  * @author Michael   */ public class Tests {     private String fname;     private String lname;     private int[] scores;       public Tests(String entry)     {         String[] data=entry.split(" ");         scores=new int[data.length-2];         this.setFname(data[0]);         this.setLname(data[1]);         for(int i=2;i<data.length;i++)         {             scores[i-2]=Integer.parseInt(data[i]);         }     }     public int[] getScores() {         return scores;     }     public void setScores(int[] scores) {         this.scores = scores;     }       public static String getAverageScore(int[] a)     {         int sum=0;         for(int e:a)         {             sum+=e;         }         return new DecimalFormat("##.##").format((double)sum/(double)a.length);     }       public static void showAverage(List<Tests> e)     {         for(Tests s:e)         {             System.out.println(s);         }     }     public String getGrade()     {         double d=Double.parseDouble(Tests.getAverageScore(scores));         if(d<=100 && d>=90)         {             return "A";         }         else if(d<90 && d>=80)         {             return "B";         }         else if(d<80 && d>=70)         {             return "C";         }         else if(d<70 && d>=60)         {             return "D";         }         else         {             return "F";         }     }     public String getFname() {         return fname;     }     public void setFname(String fname) {         this.fname = fname;     }     public String getLname() {         return lname;     }     public void setLname(String lname) {         this.lname = lname;     }     public String toString()     {         return getFname()+"\t\t"+getLname()+"\t\t"+scores[0]+"\t\t"+scores[1]+"\t\t"+scores[2]+"\t\t"+scores[3]+"\t\t"+scores[4]+"\t\t"+getAverageScore(scores)+"\t\t"+getGrade();     }       public static ArrayList<Tests> read(String path)     {         BufferedReader br = null;         try {               String sCurrentLine;             ArrayList<Tests> ar=new ArrayList<Tests>();             br = new BufferedReader(new FileReader("C:\\Users\\Michael Jr\\Desktop\\ch9_Ex13Data.txt"));               while ((sCurrentLine = br.readLine()) != null)              {                 ar.add(new Tests(sCurrentLine));             }             return ar;           }          catch (Exception e)          {           }          finally {             try {                 if (br != null)br.close();             } catch (IOException ex) {                 ex.printStackTrace();             }         }         return null;     }     public static void main(String[] a)     {         ArrayList<Tests> ar=read("E:/score.txt");         System.out.println("First_Name\tLast_Name\tTest1\t\tTest2\t\tTest3\t\tTest4\t\tTest5\t\tAverage\t\tGrade");         for(Tests e:ar)         {             System.out.println(e);         }     } }

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


I have searched on this site for about 35 minutes, and I am sure it is a really simple answer and I am probably over-looking it, but I am having trouble figuring out how to center my layout.  It is a simple layout, it has a container div, left div for the menu, and right div for the content. (Here is the CSS for this so far..)  #container {   text-align:center;    width: 960px;    background-color:#FFFFFF;    margin-right:10px;    margin-left:10px;    display:block; } #left {   text-align:;    width:300px;    display:block;    background-color:#FFFFFF;    padding-left:5px;    padding-right:5px; } #right {   text-align:left;    padding-left:10px;    padding-right:10px;    width:620px;    display:block; }   When I save it and open in my browser, the layout is just sitting to the left. What can I add to make it go to the center?  I have tried a few things from other peoples' threads and nothing is working. What am I doing wrong?

How can I horizontally center a
 within another
 using CSS?

Foo foo


Is it possible to unwrap a series of connected faces and make them keep their proportions relative to each other for precise texture placement?   I have a wall structure that has rounded corners, and when I unwrap it, the faces do not keep their proportions relative to each other, resulting in distorted/stretched textures when applied.   There must be a way to make faces keep their relative size.  I attached an image that hopefully illustrates my problem:

I've some difficulties to find a satisfactory unwrap solution for this kind of long angled object with uneven segments:      I'm only interested in the brown faces which are delimited by two seams.   The solution must preserve the relative length of each straight segment, so that the texture containing a repeated pattern can be mapped evenly on the whole length (the sample is a ceramic ).  Here is the result with a cube projection and a checker texture, other methods provide different results, but the distortion is always present:      I can't find a solution, except purely manual, to create the UV map while ensuring all segments:   Are oriented in the same direction on the map, Have their length proportional to their actual size, to prevent texture distortion.   These constraints seem quite common, is there a standard approach?  Intuitively, I'm expecting the most simple method to lead to overlapping variable length rectangles, in the same direction, anchored at a corner (or a very large single rectangle).


I have some code that is selecting a log entry (in a loop) to get the most recent inventory quantities of an item. I would like a way to always get the last occurrence of an integer in a string that will look slightly different on each iteration through the loop:  Inventory changed from 13 to 12 Inventory changed from 12 to 11 Inventory changed from 11 to 10 Inventory changed from 10 to 9 Inventory changed from 9 to 8  For each of these strings, I'll always need to return the last number(s). So if I have "10 to 11" i'll need "11", or if I have "9 to 8" i'll need "8".    I've not found a way to do this that will account for the multitude of ways that those integers will show up in that string (i.e., changed from 123 to 153, 8 to 9, 0 to 1, etc.)    Any advice would be greatly appreciated.

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


I am using the SimpleLightbox plugin () on a test site: .  If you click on one of the pictures, SimpleLightbox opens a larger version in a Lightbox. You'll notice that to close the Lightbox you need to click the white "X" in the upper-right hand corner, but that is directly over the page menu (where the three lines are).  So, I added some code that would remove the navigation bar from the page when the Lightbox loads, which looks like:  $(document).ready(function(){     $(".simplelightbox").click(function(){         $(".burger").hide();     }) });   This works because the code gets executed when someone clicks on one of the Lightbox images with the class "simplelightbox"  The problem I'm having is making the nav bar re-appear.  I have tried:  $(document).ready(function(){     $(".simple-lightbox").click(function(){         $(".burger").show();     }) });   but that doesn't work - the nav bar doesn't re-appear. That one uses class .simple-lightbox (because that is the main class when the Lightbox is showing) - there is also sl-overlay, sl-wrapper, sl-image, and sl-close but none of those worked either.  Anyone have any ideas?  Thanks, Josh

I know that jQuery is loaded, because I can switch out the $ for 'jQuery' and everything behaves as expected, but this will be a messy script if I can't fix this  This script:  jQuery(document).ready(function(){     $("ul.vimeo_desc_feed li a").click(function(){         alert($(this).attr('href'));         return false;     }) });   Produces the error $ is not a function  This script:  jQuery(document).ready(function(){     jQuery("ul.vimeo_desc_feed li a").click(function(){         alert(jQuery(this).attr('href'));         return false;     }) });   works fine.


How can I download files from a remote Linux Ubuntu server? I have access to this server, but I don't know a convenient way to download a file from there using SSH (PuTTy), for example.  Any suggestions?

Is there any way to automate the process of copying the files between windows and unix without doing it manually, using tools such as winscp.  I need to copy files from unix to windows such by executing some commands in windows. I goolged it and found these tools that can do this.  ftp sftp scp pscp winscp console.   EDIT : Can I get something using pscp because I just found out that ftp is not enable in my servers.  Please suggest a way of doing it and I need to run whatever script/command in windows only for copying the unix files.  EDIT 2 : Getting this error in winscp console for sftp :  winscp> get abc.sh c:\ abc.sh                    |          0 KiB |    0.0 KiB/s | binary |   0% Can't create file 'c:\abc.sh'. System Error.  Code: 2. The system cannot find the file specified (A)bort, (R)etry, (S)kip, Ski(p) all:


I applied for my schengen visa stating on my cover letter that I am about to finish my contract at my current employment. I am a South African working in China. I asked for 71 days in Schengen and my bank statement shows that I have at least 3 times in my balance as what is required for that period. The visa centre said without an employment letter my case won't be as strong, and said I should add it. But surely you can't add an employment letter stating employment you won't have during your travels?? My plan is to go back to South Africa after my trip. Now I am quite nervous. Should I send them an employment letter? Could they deny me because of that?

A friend from Russia (Moscow) is planning to visit me in late August. She is about to apply for a visa but she's worried that they will deny her application because she doesn't have anything to prove her willingness to return. She is 22 years old an just got her first degree in university and even though she will continue studying in the next semester, she won't have any documents from the university until September.  Is it likely that she won't get the visa? If so is there anything we can do about that, like proving she has a return ticket / reservation?  Edit: I should add that she lives with her parents (who are paying for the trip).


$PROBLEM$ :If $G$ is finite of odd order. And $H$ subgroup of $ G$ with $[G:H]=3$ then $H$ is normal.  $Proof$:     I know that that there exists a homomorphism $\phi : G \rightarrow S_3 $ Such that $ker(\phi)<H$.I know that cause of i found it in the notes calling it Poincare's Trick.But i havent found a proof.(Id love to see a proof). Now that granted.  I know $\phi(G)<S_3$  and since $\phi$ not an isomorphism since $|G|=odd$ and $|S_3|=even$.  So   $|\phi(G)|\mid |S_3|$ so $|\phi(G)|=2$ or $3$.  Now i know $$G/ker\phi \simeq \phi(G) $$ meaning  $|G/ker\phi |= |\phi(G)| $ And that must be an $odd$ since it is the $index$   of $ker\phi $  in $G$. So $$|\phi(G)|=|G/ker\phi|=3$$  Now  i know $$|G|=[G:H]|H|$$ and $$|G|=[G:Ker\phi]|Ker\phi|$$ substituting with $3$. I get  $$|H|=|Ker\phi| $$ and since $Ker\phi < H$ $\Rightarrow$ $Ker\phi=H$ .And i know  $Ker\phi \lhd G$ So its $H$ too.  Am i wrong?Afraid of some sort of circular reasoning.Also id love to see a proof of why there is such homomorphism.  Im asking if my  proof is correct and it is not a duplicate of the same problem.Since Im not asking for a proof but for a proof verification and a proof of a Trick mentioned!!

$G$ has no subgroup with index 2. How can I show that all subgroups with index 3 are normal? (The index of the subgroup is the order of the quotient set.)


I am not a pro at Mac / OS X. But I know my way around.  I just installed OS X El Capitan. However when I first started up, my harddisk used 30GB with 'other'. With time the capacity just keeps shrinking. If I just stare at the screen, I just see the available space drop and drop. Until it hits Zero Bytes at capacity.   Does anyone know what I can do about this? I cannot seem to find anything on this on Google.   The only thing it returns on my keywords are things like how to remove temporary files, re-index size with Spotlight, Startup in safe mode. None of these things seem to work.    @Edit 22:02 06-04-2016  I have checked Activity Monitor and got the following results:   I have sorted on Bytes Written, that does not seem very strange.  However if I check the Graph Data Written below it gives:   As you can see the data Written is around 8.33 GB and a few minutes later already 10 GB,.. I checked; 'sudo fs_usage -f filesys' this keeps trying to get some attribute lists from mdworker? Don't know if that is normal?    @Edit 20:30 07-04-2016 With 'sudo fs_usage -f filesys' I see that the following processes write;   nsurlsession nsurlstorage IMRemoteUrlC cfprefsd   With using Daisy Disk App I see the following:   So the private and library grows a bit, however the Core grows massively. I see that it produces a 'core dump' of around 528 mb every now and then. This tells cores is a folder for a core dump;    What/why is this happening? (Like the post I have set the core dump limit to 0 and it seems to have stopped generating.)    PS: This is not a duplicate of , I do not have time machine / Backups turned on.

Im using a program called Daisy Disk to see what is taking up space in my Mac and I find that the /cores directory is taking up 77gb.   Is that a problem? Can I get rid of it to regain the space?


I'm trying to find integer solutions to $x^2 + 11 = y^3$. I guess it will work as follows: work in the ring of integers $\mathcal{O}_K$ of the number field $K = \mathbb{Q}(\alpha)$ with $\alpha = \sqrt{-11}$. This ring is $\mathcal O_K = \mathbb{Z}[\frac{1 + \alpha}{2}]$. Here te equation becomes $(x + \alpha)(x-\alpha) = y^3$.   Now I guess we should show that the ideals $(x+\alpha)$ and $(x-\alpha)$ are coprime in $\mathcal{O}_K$. It follows that $(x + \alpha) = I^3$ for some ideal $I\subset \mathcal{O}_K$. I already showed that the class group $Cl(\mathcal O_K)$ is trivial and therefore $I$ is principal. So up to units of $\mathcal O_K$ (but these are just $\pm 1$, so we do not need to worry about them) we have $x + \alpha = \left(a + b\frac{1 + \alpha}{2}\right)^3$ for some $a, b\in \mathbb{Z}$. This equation now yield some condition for $a$ and $b$ and we are able to find the solutions to $x^2 + 11 = y^3$, they are $(\pm 4, 3)$. I have two questions.   Is this proof correct (when given with all the details of course)? Do I miss something? How do I prove that $(x + \alpha)$ and $(x-\alpha)$ are coprime in $\mathcal O_K$ ? This probably should not be that hard, but I haven't succeeded yet.    Thanks!

The equation $y^2 = x^3 + k$ for $k = (4n-1)^3 - 4m^2$, with $m, n \in \mathbb{N}$ and no prime number that p is congruent to 1 modulo 4 divids m, doesn't have any answer and its proof can be obtained by using quadratic reciprocity law.  Do you know answers of this equation for two or three different values of $k$? In addition, do you know any reference about that?


Many papers use nonstandard data sets, which means the authors could have manipulated the data behind the scenes to make their paper look more impressive.  It seems that this could be done very easily: for example, one could cherry pick the items of the data set to make it seem like an algorithm has 90%+ accuracy while in reality it's about 60%.  What prevents people from doing this?  Is there something I'm missing?

I am preparing a paper in the field of Computer Science.  In order to report test results, we usually run a number of tests and report the average of those tests.  For each test, we generate random data.  Because of the randomness, at some points, the results may come out not as expected.  For instance, a graph may be like:   Usually, one should explain why on points 8, 11 and 12 there is a decrease on the plot. Probably, it is because of that randomness.  Not hand-crafting all the graph, but just manipulating a few points makes the graph acceptable:   Since three weeks or so, I work my ass off and try to figure out why my resulting graph looks like the first one. Sometimes I feel like yielding to temptation and just modify the raw data before I go crazy.  I believe, at this point the title became misleading, so let me make it clear:  I am not seeking an advice on data manipulation. I will not manipulate my data. However, I ask to myself "how the hell this can be detected?"  And now, I don't only ask to myself, but to whole community. How is this detected? For editors, referees out there, have you ever detected something like this?


Good Morning, I have a doubt. I am doing a panel data model to calculate the benchmarking of some companies in the sector. is there any test that I can apply to know if I use fixed or random effects? I'm using eviews.

I've got a weird question. Assume that you have a small sample where the dependent variable that you're going to analyze with a simple linear model is highly left skewed. Thus you assume that $u$ is not normally distributed, because this would result in normally distributed $y$. But when you compute the QQ-Normal plot there is evidence, that the residuals are normally distributed. Thus anyone can assume that the error term is normally distributed, although $y$ is not. So what does it mean, when the error term seems to be normally distributed, but $y$ does not?


A fly is flying between two trains, each travelling towards each other on the same track at 30 km/h. The fly reaches one engine, reverses itself immediately, and flies back to the other engine, repeating the process each time. The fly is flying at 60 km/h.  At the start the trains were separate for 180 km.  What is the distance that the fly travels to the moment when both of the trains hit each other?

Two trains travel on the same track towards each other, each going at a speed of 50 kph. They start out 100km apart. A fly starts at the front of one train and flies at 75 kph to the front of the other; when it gets there, it turns around and flies back towards the first. It continues flying back and forth till the two trains meet and it gets squashed. How far did the fly travel before it got squashed?  The question is relatively simple - the trains take an hour to collide, and in an hour the fly would travel 75 km. However, the question got me wondering: Lets say you are given a time $t$ in hours(where $t< 1$) How many "rounds" would the fly make in $t$ time? A round  is defined as moving from one train to another and back. How would I model the equation?


Small disclosure I am doing a course that requires learning statistics but it is not my field of expertise so I may make several mistakes, apologies in advance. Also, I will add some background as suggested, but the question is at the end of the post if someone does not want to read everything. The Dataset I have a large dataset I got from Kaggle with 8000 observations of different individuals. Each individual has 4 binomial attributes (so 1 or 0), i.e. Male (1) or Female (0). There are 5 other columns with continuous variables, i.e one is "average number of characters per post". What I am trying to understand I wanted to see if for each of these continuous variables there were significant differences among the different groups (so for each attribute). Process This is where I am less confident about. I thought it would make sense to do the non-parametric Mann-Whitney U Test to compare each group. However, since I am comparing 4 pairs of categories simultaneously, I thought that it would be sensible to adjust the obtained p-values to prevent an increased risk of committing a type 1 error. So I thought of using the Bonferroni correction (if this makes sense...) The results So I decided to start comparing Group A and Group B for the category "Average Number per Posts". The Mann-Whitney Test gives me the following statistic and p-value: Statistics=-25707067.000, p=0.000 The problem is that when I look at the data, this result seems to be very far fetched, here are some descriptive statistics and a box plot:   For me, the groups are almost identical, I would have guessed that I would not have found grounds to reject the null hypothesis. Question I am a bit lost trying to understand the reason behind these results. With such a large sample, can these minor differences give a significant p-value? I guess that statistical significance does not mean that something is relevant in real life but are these results possible or most likely a consequence of a mistake I made in the process? Should I have done something different? Possible mistakes?  Result of a bad study design and statistical process Result of bad programming (this will be impossible for you to determine but I guess it's possible) Correctly computed but misinterpretation of the results Combination of the previous or other  Any way, thanks and sorry for the long post.

I have completed my data analysis and got "statistically significant results" which is consistent with my hypothesis. However, a student in statistics told me this is a premature conclusion. Why? Is there anything else needed to be included in my report?


I was watching a youtube video about the expansion of the universe. So the video said that the universe is expanding at a speed faster than the speed of light. I have 2 questions about that. My first question is doesn't this contradict einstein's theory of relativity that states nothing can travel faster than the speed of light.  please note that i did look at some other questions similar to this one but i couldnt find an answer to my question. My second question is where does the universe expand to. If the unviverse holds all matter then where does it expand to. If it expands to nothing there would be nothing to expand to right. Is the universe creating space? ps, please keep in mind i am only 13 so it would be great if you could keep your answers as simple as possible.

just after the Big Bang and before inflation the currently observable universe was the size of a coin. One millionth of a second later the universe was the size of the Solar System, which is an expansion much much faster than speed of light. Can space expand with unlimited speed?


When I start up Chrome, "netstat -taupen" shows 92.242.140.21 connecting to a random port number, usually above 20,000. The IP is from the UK and is tied to Barefruit Ltd. Exactly what is connecting this IP to my computer when I use Chrome?  If it has something to do with the ISP,  I use Verizon.  Here is the terminal shows  Local Address        Foreign Address     State        User   Inode    PID/Program Name 192.168.1.3:33883    92.242.140.21:80     TIME_WAIT    0      0        -   Also  Local Address        Foreign Address     State        User   Inode    PID/Program Name 192.168.1.3:33881    92.242.140.21:80     TIME_WAIT    0      0        -

I run Ubuntu 14.04. Using the terminal, I did netstat -taupen to see what processes are running and I got this result:  Local Address        Foreign Address     State        User   Inode    PID/Program Name 192.168.1.3:54179    23.62.236.99:80     TIME_WAIT    0      0        -   Why is this ip connected to one of my ports? Also, ShieldsUp says port 54179 is stealthed, so what is going on?


I have two servers with expired contracts that are both vulnerable to shellshock.  I am in the process of migrating both to new servers with RHEL6 or greater depending when I get this done.  That being said, running yum fails due to no contract which for such a high level bug, is really shameful of Red Hat.    Nevertheless, how do I get the rpm so I can manually upgrade on both servers?  They are: Linux intranet 2.6.18-238.12.1.el5PAE #1 SMP Sat May 7 20:37:06 EDT 2011 i686 i686 i386 GNU/Linux  Thank you very much!

I'm trying to update bash on our Red Hat Enterprise Linux Server release 5.6 server. But it won't find an update later than "3.2-24.el5". I've check and it is vulnerable for the shellshock vulnerability. I've done yum clean-all, yum update bash, yum reinstall bash. But it always comes back to just version "3.2-24.el5".  Can anyone help?  Thanks


The canonical commutation relation states that $$[x,p] = i \hbar\ \mathbb{I}$$ if we imagine to be in a one dimensional space. If we take the mean value of the commutator over an eigenstate of the position $|x'\rangle$ we get $$\frac{\langle x'| [x,p] |x'\rangle}{\langle x'|x'\rangle} = \frac{\langle x'| i \hbar\ \mathbb{I} |x'\rangle}{\langle x'|x'\rangle} = i \hbar.$$ Now, instead of using the canonical commutation we write the commutator explicitly $$\frac{\langle x'| [x,p] |x'\rangle}{\langle x'|x'\rangle} = \frac{\langle x'| xp |x'\rangle}{\langle x'|x'\rangle} - \frac{\langle x'| px |x'\rangle}{\langle x'|x'\rangle}.$$ In the first term of the difference the operator $x$ acts on the bra giving the eigenvalue $x'$, while in the second term the operator $x$ acts on the ket giving again the eigenvalue $x'$, then $$\frac{\langle x'| [x,p] |x'\rangle}{\langle x'|x'\rangle} = \frac{x' \langle x'| p |x'\rangle}{\langle x'|x'\rangle} - \frac{x' \langle x'| p |x'\rangle}{\langle x'|x'\rangle} = 0.$$ I know obviously the second result it's the wrong one. Can someone point the error I'm making in the second calculation?

Let $\hat{x} = x$ and $\hat{p} = -i \hbar \frac {\partial} {\partial x}$ be the position and momentum operators, respectively, and $|\psi_p\rangle$ be the eigenfunction of $\hat{p}$ and therefore $$\hat{p} |\psi_p\rangle = p |\psi_p\rangle,$$ where $p$ is the eigenvalue of $\hat{p}$. Then, we have $$ [\hat{x},\hat{p}] = \hat{x} \hat{p} - \hat{p} \hat{x} = i \hbar.$$ From the above equation, denoting by $\langle\cdot\rangle$ an expectation value, we get, on the one hand $$\langle i\hbar\rangle = \langle\psi_p| i \hbar  | \psi_p\rangle = i \hbar \langle \psi_p | \psi_p \rangle  = i \hbar$$ and, on the other $$\langle [\hat{x},\hat{p}] \rangle = \langle\psi_p| (\hat{x}\hat{p} - \hat{p}\hat{x}) |\psi_p\rangle =  \langle\psi_p|\hat{x} |\psi_p\rangle p - p\langle\psi_p|\hat{x} |\psi_p\rangle = 0$$ This suggests that $i \hbar = 0$. What went wrong?


I want to write a Christmas lottery algorithm. I want the people I enter in my hand to be matched with other people who are not themselves and printed on the screen. I wrote a code like the one below. But because it removes an element from the list every time, my program matches fewer people than the number of people entered. How can I find a solution to this problem? List<string> person = new List<string>() { "Joe","John","Chris","Henry","Tom","Patrick"};         List<string> personCopy = new List<string>(person);          for (int i = 0; i < person.Count; i++)         {             string person1 = person[i];             Random rnd = new Random();             var index = rnd.Next(personCopy.Count);             while (i == index) {                 index = rnd.Next(personCopy.Count);             }              string person2 = personCopy[index];             person.RemoveAt(i);             personCopy.RemoveAt(index);             Console.WriteLine("{0}  > {1}",person1,person2);                      }

What is the best way to randomize an array of strings with .NET? My array contains about 500 strings and I'd like to create a new Array with the same strings but in a random order.  Please include a C# example in your answer.


Usually, the best way to recover a deleted file is to have backups and that, if the backup failed, you should immediately remount the drive read-only. (See this thread:  )  But in some occasions, if the deleted file wasn't that important, it just would save some time to just "undelete" it.  Is there a simple way I could try on bash for the case that the deleted file on an ext4 filesystem was the only file on the disk, especially, if the disk is not used otherwise?

Is there a command to recover/undelete deleted files by rm?  $ rm -rf /path/to/myfile   How can I recover myfile? If there is such a tool how can I use it?


Is it OK to combine categorical and continuous features into the same vector for training deep neural networks? Say there is a categorical feature and continuous feature that I want to feed into a deep neural net at the same time. Is this the way to do it? categorical feature (one-hot encoded) = [0,0,0,1,0] continuous feature (number) = 8 final feature vector passed into neural network = categorical feature vector CONCATENATE continuous feature = [0,0,0,1,0,8]  Basically, the question is, is it OK to have a one-hot encoding and a continuous feature together in one feature vector?

I have dataset of 15 features and the goal is to estimate a best fitting curve (regression). Now I want to use a deep learning technique for this purpose. Now I see that there are many architectures that can be used such as CNN, DBM or auto-encoder, etc.. Which one to go for. And I could not find any examples for how to use the same. A sample code would be of great help. Thanks  P.S. Some of the features are categorical. How do we handle that as well?


I have a family member with a 3rd Gen iPad (a1416) currently running iOS 6. They need to install an app that requires iOS 7. When looking at the system upgrade page in settings, it shows iOS 9 which I believe isn't compatible and also would probably run pretty slow anyway.   Is it possible to upgrade this 3rd Gen iPad to iOS 7? How can we do that? Thanks!  PS: I've already looked at  but the site mentioned in the answer there doesn't offer a signed iOS 7 image.

How do I upgrade my iPad 3 from iOS 5.1 to 7.x (now when the latest version is >8)?


I have an CLI app which works by navigating to the dir using cd and then executing program 2fa, code  The problem is that those commands works only if Im on that specific folder. How I can make a alias which will be widely understood? So I can 2fa everywhere, even I'm on /home.

I frequently run the ls command after running the cd command. How can I create an alias (like cs) for this operation?


Please help me to prove this trigonometric equation.  $\cos \left( 36^\circ \right)-\cos \left( 72^\circ \right) = \frac{1}{2}$  Thank you.

How do we prove $\cos(\pi/5) - \cos(2\pi/5) = 0.5$ without using a calculator.  Related question: how do we prove that $\cos(\pi/5)\cos(2\pi/5) = 0.25$, also without using a calculator


The problem is showing that $x^2=a$ has a solution for each $a\in G$ if $G$ is a finite group of odd order. Heres what I got so far (my lecturer told me to do it this way): Since $G$ is of odd order, we can express $1_G$ as: $a^{2n-1}=1_G$. If we multiply both sides by $a$ we get $a(a^{2n-1})=a^{2n}=a$. Now this is where I am stuck, how do I proceed from here? Any hints are greatly appreciated!

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


So I'm thinking of upgrading the RAM on my computer: currently I have two RAM chips, one 1 GB and one 4 GB.  I'm debating on what's the best way to do the upgrade to get the best performance.  Here's what I have in mind: upgrading my RAM to maximize my performance as best I can.  I was originally thinking of swapping out the 1 GB RAM chip for a 16 GB RAM chip for a total of 20 GB.  However, a few people mentioned that I'd be better off swapping out both chips for two 8 GB chips running in dual channel mode than going with 20 GB total.  This seems a bit odd to me, but I'm more of a software person than a hardware person, not knowing much about how hardware works.  Thus, my question is: which would these options would be faster?  A system with 20 GB, with a 16 GB chip and a 4 GB chip or a system with 16 GB, two 8 GB RAM chips running in dual channel mode.  As far as operating systems go, I'm running Windows 7 64 Bit, although I'm thinking of creating a new partition to run Debian Linux one of these days on my computer.  However, the Windows OS is the one I care about for the most part since it's always going to be the one used the most.

I know there a lot of posts about ram but I'm still confused about it. I'm building a new system and because it was cheaper, I bought a 6GB kit from Corsair. So I'm wondering if I would be better off just using 4GB of it in a dual channel configuration or just add all 6GB (3 DIMMS) in a single channel configuration.   Thanks


I have a doubt regarding id() in python.  >>> x=2 >>> y=2 >>> id(x) 94407182328128 >>> id(y) 94407182328128   But if i do the same to list,i get different id's   >>> a=[1,2,3] >>> b=[1,2,3] >>> id(a) 139700617222048 >>> id(b) 139700617135528   WHY is it so? why for int type i get the id's same and why different for lists?  Thanks in Advance.

Why does the following behave unexpectedly in Python?  >>> a = 256 >>> b = 256 >>> a is b True           # This is an expected result >>> a = 257 >>> b = 257 >>> a is b False          # What happened here? Why is this False? >>> 257 is 257 True           # Yet the literal numbers compare properly   I am using Python 2.5.2. Trying some different versions of Python, it appears that Python 2.3.3 shows the above behaviour between 99 and 100.  Based on the above, I can hypothesize that Python is internally implemented such that "small" integers are stored in a different way than larger integers and the is operator can tell the difference. Why the leaky abstraction? What is a better way of comparing two arbitrary objects to see whether they are the same when I don't know in advance whether they are numbers or not?


I was just wondering If anyone knew any good ways to prevent Sql Injections on this code. The Last thing I want is someone hacking my database. I am fairly new to this and would like to hear expert opinions. Thanks.  <?php     $input = $_GET['input'];//Note to self $input in the name of the search feild     $terms = explode(" ", $input);     $query = "SELECT * FROM content WHERE ";      foreach ($terms as $each){         $i++;         if ($i == 1)             $query .= "keywords LIKE '%$each%' ";         else             $query .= "OR keywords LIKE '%$each%' ";     }      // connecting to our mysql database     mysql_connect("localhost", "username", "password");     mysql_select_db("database");      $query = mysql_query($query);     $numrows = mysql_num_rows($query);             if ($numrows > 0){                  $i = 0;                              while ($row = mysql_fetch_assoc($query)){                               $i++;              $id = $row['id'];             $title = $row['title'];             $description = $row['description'];             $keywords = $row['keywords'];             $link = $row['link'];             $plink = $row ['plink'];             $views = $row ['views'];                  if($i == 3){             echo '

'.$title.'
Total views: '.$views.'

';                }               else{              echo '

'.$title.'
Total views: '.$views.'

'                            ;                  }                      }           }          else         echo "No results found for \"$input\"";        // disconnect     mysql_close(); ?>

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


I make my class generic.The T - can be string or int.  I have this feature class:    public class Feature<T>// : IComparable {     public T CurrentFeatureCode { get; set; }      public T StreetCode1 { get; set; }     public T BuildingNumber1 { get; set; }     public string BuildingLetter1 { get; set; }      public T StreetCode2 { get; set; }     public T BuildingNumber2 { get; set; }     public string BuildingLetter2 { get; set; }      public double CoordinateX { get; set; }     public double CoordinateY { get; set; }      public string Filter { get; set; }      public string ToString(T streetCode)     {         return StreetCode2 == streetCode ? String.Format("{0}{1}", BuildingNumber2, BuildingLetter2) : String.Format("{0}{1}", BuildingNumber1, BuildingLetter1);     } }   As you can see I have ToString method inside Feature class that compares two values:  StreetCode2 == streetCode ? String.Format("{0}{1}", BuildingNumber2, BuildingLetter2) : String.Format("{0}{1}", BuildingNumber1, BuildingLetter1);   I  get error on this row:  Error   11  Operator '==' cannot be applied to operands of type 'T' and 'T' .   My question is how can I compare two values of T type?

According to the documentation of the == operator in ,      For predefined value types, the   equality operator (==) returns true if   the values of its operands are equal,   false otherwise. For reference types   other than string, == returns true if   its two operands refer to the same   object. For the string type, ==   compares the values of the strings.   User-defined value types can overload   the == operator (see operator). So can   user-defined reference types, although   by default == behaves as described   above for both predefined and   user-defined reference types.   So why does this code snippet fail to compile?  bool Compare<T>(T x, T y) { return x == y; }   I get the error Operator '==' cannot be applied to operands of type 'T' and 'T'. I wonder why, since as far as I understand the == operator is predefined for all types?  Edit: Thanks, everybody. I didn't notice at first that the statement was about reference types only. I also thought that bit-by-bit comparison is provided for all value types, which I now know is not correct.  But, in case I'm using a reference type, would the == operator use the predefined reference comparison, or would it use the overloaded version of the operator if a type defined one?  Edit 2: Through trial and error, we learned that the == operator will use the predefined reference comparison when using an unrestricted generic type. Actually, the compiler will use the best method it can find for the restricted type argument, but will look no further. For example, the code below will always print true, even when Test.test<B>(new B(), new B()) is called:  class A { public static bool operator==(A x, A y) { return true; } } class B : A { public static bool operator==(B x, B y) { return false; } } class Test { void test<T>(T a, T b) where T : A { Console.WriteLine(a == b); } }


I can find dozen of tutorials on how to apply texture to one face of an object in Blender Render, but nothing for Cycles Render!  I selected the faces I wanted, added material, chose an image texture, brought up the uv editing screen, did the smart uv project, made sure the correct texture was selected.   Didn't work; the object is still 100% the first texture I had applied.  Any tips?

How do you add more than one material to a mesh?   I have tried adding two materials to the object, and then assigning one of the materials to a vertex-group, but I could not find a place to assign it.  I am making a striped bouncy ball that I want to deform, so adding a different material by separating the mesh into different objects would not be ideal.


Is there a specific word for a person who has just been released from jail?

What do you call a former criminal who has served their sentence and been released from prison?  I thought of “convicted criminal”, but that might imply the person is still a criminal and/or serving a sentence.   Does “convicted criminal” fit this definition? Are there other--better--words that are more accurate?


when I load this in my browser this is the error that I receive but I cant seem to find out what is wrong with it. Does anyone have any suggestions on how to solve this issue.  <?php   define('DOCUMENT',"C:/XAMPP/htdocs/test/"); define('DOC_ROOT' , DOCUMENT); define('DS' , "/");  define('INCLUDES', DOC_ROOT . 'includes'. DS);  define('MYSQL_DIR' , DOC_ROOT . 'mysql' . DS  ); define('MODELS_DIR' , DOC_ROOT . 'mysql' . DS . 'models' . DS );  require_once MYSQL_DIR . 'db_connect.php';    ?>   Warning: require_once(C:/XAMPP/htdocs/test/mysql/db_connect.php): failed to open stream: No such file or directory in C:\xampp\htdocs\test\defines.php on line 12  Fatal error: require_once(): Failed opening required 'C:/XAMPP/htdocs/test/mysql/db_connect.php' (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\test\defines.php on line 12

How do you debug PHP scripts?  I am aware of basic debugging such as using the Error Reporting. The breakpoint debugging in PHPEclipse is also quite useful.  What is the best (in terms of fast and easy) way to debug in phpStorm or any other IDE?


I have already created a Trial User on Salesforce but I can not access into Marketing Cloud. How can I have a Trial User on Marketing Cloud?

Has there been any progress made on granting a developer account for SF and HubExchange Devs? It feels conceptually wrong to me a SF product doesn't allow developers to perfect and develop a wider solution offering without paying +10K license fee per year. Even without CRM the HubExchange market could be a richer portal for consumers and developers if we were allowed a means to test our concept.  I think we'd all be perfectly happy with an account that was blackholed or limited in such a way where we could only send a finite qty of emails to an email address associated to the user.  If there's a forum or avenue where we can assist in raising the value proposition please let us know as I know there are many people looking.


I assume that that a single /swap & /home partition will suffice for different os but each root / partition to be created for each of them but not sure whether each /boot partition are required or a single /boot partition will take care of the all linux os?

I ran the default install of CEntOS 6.5 on my machine a couple months ago and have since added programs and files which I don't want to get rid of. I'd like to dual boot Ubuntu 14.x and am wondering what to do with the /boot partition. The hard drive is currently partitioned like so:  sda: 256 GB SSD   sda1: /boot 500 MB sda2: /LVM physical volume ~237 GB   /root /home swap     My question is: Is it OK to share the /boot partition between distros? or do I need to have a separate /boot partition for Ubuntu? If so, is it necessary to put the /boot partition at the beginning of the drive?


I want to placing the signature between "Sincerely and Name". Using the latex  commands French Cursive: {\cursive\setul{0.1ex}{}\ul{~~Mickly~~}}  \documentclass[11pt]{letter} % Default font size of the document, change to 10pt to fit more text  \usepackage{newcent} % Default font is the New Century Schoolbook PostScript font \usepackage{soul}% for the underlining \usepackage[doublespacing]{setspace}% just to set the samples further apart  \usepackage{emerald}% for 1-4 \usepackage{frcursive}% for 5 \usepackage{inslrmin}% for 6  \usepackage[T1]{fontenc}  %\usepackage{helvet} % Uncomment this (while commenting the above line) to use the Helvetica font  % Margins \topmargin=-1in % Moves the top of the document 1 inch above the default \textheight=8.5in % Total height of the text on the page before text goes on to the next page, this can be increased in a longer letter \oddsidemargin=-10pt % Position of the left margin, can be negative or positive if you want more or less room \textwidth=6.5in % Total width of the text, increase this if the left margin was decreased and vice-versa  \let\raggedleft\raggedright % Pushes the date (at the top) to the left, comment this line to have the date on the right  \begin{document}  %---------------------------------------------------------------------------------------- %   ADDRESSEE SECTION %----------------------------------------------------------------------------------------  \begin{letter}{Professor \\ Institut \\ University\\ City, Country 123456}  %---------------------------------------------------------------------------------------- %   YOUR NAME & ADDRESS SECTION %----------------------------------------------------------------------------------------  \begin{center} \large\bf Mick Fre \\ % Your name \vspace{20pt} \hrule height 1pt % If you would like a horizontal line separating the name from the address, uncomment the line to the left of this text Street \\ City, Country 123456 \\ 111-333-111 % Your address and phone number \end{center}   \signature{Name} % Your name for the signature at the bottom  %---------------------------------------------------------------------------------------- %   LETTER CONTENT SECTION %----------------------------------------------------------------------------------------  \opening{Respected Professor:}  JD: {\ECFJD\setul{0.1ex}{}\ul{~~Mickly~~}}  Skeetch: {\ECFSkeetch\setul{0.1ex}{}\ul{~~Mickly~~}}  Teen Spirit: {\ECFTeenSpirit\setul{-0.1ex}{0.3pt}\ul{~~Mickly~~}}  Tall Paul: {\ECFTallPaul\setul{0.15ex}{}\ul{~~Mickly~~}}  French Cursive: {\cursive\setul{0.1ex}{}\ul{~~Mickly~~}}  Insular Minuscule: {\iminfamily\setul{0.1ex}{}\ul{~~Mickly~~}}  \closing{Sincerely yours,} \end{letter} \end{document}

Nowadays many job applications are sent in digital form as PDF. We use of course LaTeX to create such. Usually you add a cover letter to your CV and credentials. If you sent this as print-out by classic mail you sign this letter (at least in Germany), but what (and how) do you do for an online application?  I would say either:   leave it empty add your name in the usual font as normal text add your real signature as scanned image add your name in a special font so that it look more like a signature (but you can still see that it isn't a real one)   I'm planning to go with the last method and I'm looking for suitable fonts for it which I can use with PDFLaTeX (XeLaTeX and LuaLaTeX answers are fine too, but will be taken as non-competitive). I would also be happy to get some style guidelines if I should not got with an other method (with a rationale to avoid subjective opinions).    I already had a look at   which is similar but still too different. I don't need or want any rule and the shown font in the accepted answer are looking too real.


I saw this step being used in another proof. We have been shown that this is true of $k=2$, but not this general form.

To prove the convergence of the p-series   $$\sum_{n=1}^{\infty} \frac1{n^p}$$  for $p > 1$, one typically appeals to either the Integral Test or the Cauchy Condensation Test.  I am wondering if there is a self-contained proof that this series converges which does not rely on either test.    I suspect that any proof would have to use the ideas behind one of these two tests.


I have learned in my HS physics 2 class that everything with mass has a wavelength given by the deBroglie wavelength. My question is : Does this mean that any object can show diffraction, such as in the Davisson-Germer experiment showing the diffraction of electrons? Does this also mean that objects may display different properties of a wave too? (Refraction/reflection)

In double slit experiment only small sized particles were used. however if we use large objects such as a tennis ball, the expected pattern is not observed.   Why the wave nature is not visible for large objects in double slit experiment ? How do I then prove that large objects also have wave nature?


Suppose that $m$ and $n$ are integers with greatest common divisor $1$. For convenience assume that both are greater than $1$. Prove that the set { $0 · n, 1 · n, 2 · n, . . . ,(m − 1) · n$ } is a complete residue system modulo $m$.   I am blank on how to solve this problem. Help would be much appreciated. Thanks!

I have this problem assigned for homework and I'm struggling with the proof of it:  If $a_1,a_2,\dotsc,a_n$ is a complete set of residues modulo $n$ and $\gcd(a,n)=1$, prove that $aa_1,aa_2,\dotsc,aa_n$ is also a complete set of residues modulo $n$.  (Hint: It suffices to show that the numbers in question are incongruent modulo $n$.)  I'm in elementary number theory so I'm not allowed to use an high-level theorems to prove this, I pretty much have to use the basics of modulo.  Thanks!


I am new on Ubuntu and I have a lot of software like itunes, canon image and printer software which have been installed under Microsoft. Do I have to reinstall them on Ubuntu? Or can I run them via Ubuntu? thank you in advance (even if it may seem like a naive question) ronmylo

Can .exe and .msi files (Windows software) be installed in Ubuntu?


I know that the Central Limit Theorem states that if a random sample of size $n$ is drawn from iid random variables $X_1, \ldots, X_n$, then the variable $$ Z = \frac{\hat x - E(X) }{{\rm sd}(\hat x)}\text{ is }\mathcal N(0,1)  $$ as $n$ is big enough (where $\hat x$ denotes the sample average).  My question is: What about $\hat x$, does it also converge to a normal distribution?

What is wrong with the following sentence:      The Central Limit Theorem  implies that, as the sample size grows, the error distribution approaches normality.   Am I correct by saying that it should in stead state the MEAN of the sample error approaches zero as sample size grows?


I need to dynamically attach a function to a div and pass also the event.  It is working in Chrome / IE, but not FireFox.  I am getting the following error in FireFox console: ReferenceError: event is not defined  How can this be solved?  CodePen:
When clicking on this div, you should get an alert with the event details. This does not work in FireFox.

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.


I am writing a paper where I consistently write $\bigwedge_R$ in-line. However, in one place, I write $$\bigwedge_R$$ in display mode. This has the effect of placing the R underneath the wedge symbol. I would like to avoid this. I tried writing $$\bigwedge{}_R$$, which places the R to the right of the wedge like I want, but it makes the R appear too high up. I also don't want to use \textstyle since I want the \bigwedge to appear as a display-style wedge. Is there a natural way to force latex to put the R on the right of the wedge so that the vertical positioning looks correct?

I'm very familiar with how symbols display differently in inline mode (with $ ... $) vs. how display math shows them (with \[ ... \] or $$ ... $$).  Two examples would be with limits  $\lim_{n\rightarrow \infty}f(x)$   vs.  \[ \lim_{n\rightarrow \infty}f(x) \]   and with sums  $\sum_{n=1}^{x} n^2$   vs.  \[ \sum_{n=1}^{x} n^2 \]   My Question is:     How do you display these things in inline mode (with all the nice inline formatting) as if they were in display mode ?   The inverse -- how to display things in display mode as if they were in inline mode -- is also of interest.


I have already installed ImageMagick on my server which is running centos 6.4  yum install ImageMagick  Version is very old : 6.5.4-7 2012-05-07 Q16  I discussed about this with ImageMagick's official forum. They told i am running older version of ImageMagick.  With yum, we generally don't need to worry about dependencies. I created few scripts which are using the ImageMagick's latest version. But my server is running the older version to support those scripts.  1) So, If i remove the yum version of ImageMagick, which dependencies should be installed before compiling ImageMagick? The scripts which are running properly shouldn't get affected by this update.  2) Right now, /usr/bin/convert is the path. How do i compile keeping the same path?     --prefix="/usr" (is it right?)  I don't have any test server. So, I need your help. I am windows(7) user!

This is a  about Compile Dependencies and Package Management.    I have a question regarding compiling ports/software or installing RPMs on my *nix server.  When I try to do this I receive lots of messages about missing dependencies.  Can the Server Fault community please help?


Let $f$ be entire and $B \subset \mathbb C$. Let $Bd( B)$ denote the boundary of $B$. What you can conclude about $f(Bd( B))$ and $Bd(f(B))$, where $B$ is open and bounded. Is there any result available in case of unbounded sets?

Let $f$ be an entire function and $B$ be a bounded open set in $\mathbb {C} $. Prove that boundary of image of $B$ under $f$ is contained in image of boundary of $B$. Does the same result is true for unbounded open set in $\mathbb C.$


hi I have made a olaf model with textures and materials and I want to sell this model but I don't know to export the textures and materials in a FBX and OBJ file

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


I saw this online before and I was wondering if it is possible in TeXStudio.  The person had equations in their script appear as it would be in the pdf, unless either the cursor hovered over the script or the typing thing was there. Is this feature possible in TeXStudio?  Edit: I want the maths stuff to stay where it is in the script, but just appear as an equation and not as script.

Is there an option to show the formulas in the text editor (not the PDF on the side) so that the text can be edited while the compiled formulas appear. This option exists in emax-auctex. Does it exist in editors like TeXstudio?


Is there a way to print out all the attributes of a python object along with their values  For example, for the following class and object  class man:     def __init__(self):       name = "jim"       age = 2  him = man()   I want to print out all the attributes of the object "him" as well as their values. I want some kind of code that acts like the following  for variable_name of him:     print variable_name," : ",him.variable_name   should print out  name : jim age : 2   Is there any way to do that in python?

dir(re.compile(pattern))    does not return pattern as one of the lists's elements. Namely it returns:  ['__copy__', '__deepcopy__', 'findall', 'finditer', 'match', 'scanner', 'search', 'split', 'sub', 'subn']   According to the manual, it is supposed to contain      the object's attributes' names, the   names of its class's attributes, and   recursively of the attributes of its   class's base classes.   It says also that     The list is not necessarily complete.   Is there a way to get the complete list? I always assumed that dir returns a complete list but apparently it does not...  Also: is there a way to list only attributes? Or only methods?  Edit: this is actually a bug in python -> supposedly it is fixed in the 3.0 branch (and perhaps also in 2.6)