I have Ubuntu 14 as host os. And I have installed VirtualBox inside ubuntu. Now as a guest OS i have installed windows 7. And i want to access USB drive inside this Guest windows 7.  please guide me to follow the steps.

I'm using Ubuntu Maverick and Virtual Box 3+. I have Windows 7 Ultimate. The problem is that it doesn't detect USB drives in Windows 7, but USB peripherals (mouse + keybord) are working.  I followed , but I can't find the user group vboxusers. How can I continue? I would also like to upgrade to the latest version without any risk (without losing my virtual hard disk drive).


In Star Trek: The Motion Picture, Kirk says the following:     in order to intercept the Intruder at the earliest possible time, we   must now risk engaging Warp drive while still within the solar system   My question, then, is what exactly is the risk of engaging Warp drive within a solar system?

In the middle of , the crew of the Enterprise-D is flying on a rescue mission toward Bersallis III, to save a Federation outpost from an impending fire-storm.  Upon reaching Bersallis III’s system, the ship drops out of warp. During senior officers meeting Riker states that it will take another hour to reach Bersallis III, so LaForge's team will have another two hours for a rescue transportation. When Riker tells this, we can clearly see, through windows behind him, that the ship is indeed travelling on conventional engines.  Why? Wouldn't it be more efficient in terms of rescue mission, to fly in warp until reaching the planet and not to waste another hour of precious time travelling?


I am sick of correcting the alignment of the last two columns and its multirows  I want  21 dimensions reduced to 9 dimensions   comes exactly side by side to   Combine accuracy of 9 dimensional reduced  Feature Vector is 80\%   SIMILARLY  9 dimensions Further reduced to 7 dimensions   comes side by side to  Combine accuracy of 7 dimensional reduced     Feature Vector is 88\%   SIMILARLY same for the last "row"    \documentclass[journal]{IEEEtran} %\usepackage{array} % loaded twice \usepackage{multicol} \usepackage{graphicx} \usepackage{rotating}% added, for rothead \usepackage{array, makecell, multirow, tabu}%merged in one line %\newcolumntype{L}[1]{>{\raggedright\let\newline\\\arraybackslash\hspace{0pt}}m{#1}} % not used %\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}} \newcolumntype{C}[1]{>{\centering\arraybackslash}m{#1}}% in this table is better use this definition \begin{document} \begin{table*}   \settowidth\rotheadsize{DIMENSIONS}   \renewcommand\multirowsetup{\centering}    \renewcommand{\arraystretch}{1.5}   \centering   \caption{Extreme Learning Machine(ELM) with kernel classifier accuracy of   combine reduced feature vectors whose individual classifier accuracy was low}   \begin{tabular}{|l|l|r|C{1.5cm}|C{1.5cm}|C{1.5cm}|C{2cm}|C{2.5cm}|}     \hline      Algorithm     & Dimension         &  \multirow{6}{*}{\rothead{ADD THESE\\ DIMENSIONS}}             & Total after Adding Dimensions                 & Classifier                     & Dimension Reduction Technique                         & Reduced Dimension                             & Accuracy  \\      \cline{1-2} \cline{4-8} LBP & 4D    &               & \multirow{5}{=}{4D + 6D + 4D\\ + 3D + 4D = 21D}                  & \multirow{5}{=}{ELM with RBF kernel}                      & \multirow{4}{=}{Eigenvalue as Dimension Estimator,                                           PCA as Dimension Reduction}                          & \multirow{4}{=}{21 dimensions reduced to 9  dimensions}                                        \newline                                & \multirow{4}{=}{Combine accuracy                                                  of 9 dimensional reduced                                                   Feature Vector is  80\%}\smallskip\newline \\     \cline{1-2} RGLBP  & 6D    &   &   &   &  &\multirow{5}{=}{9 dimensions Further                                                   reduced to 7 dimensions}                                             &\multirow{5}{=}{Combine accuracy                                                            of 7 dimensional  reduced                                                                Feature Vector is  88\% } \newline       \\     \cline{1-2} BDIP   & 4D    &   &   &   &   &\multirow{7}{=}{7 dimensions Further                                                   reduced to 6 dimensions}                                         &\multirow{7}{=}{Combine accuracy of 6                                                     dimensional reduced                                                     Feature Vector is 100\% }\newline   \\     \cline{1-2}  HOG      & 3D    &   &   &    &   &   &   \\     \cline{1-2}  Combine and     & 4D    &   &   &    &   &   &    \\  reduced fv of   &       &   &   &       &   &   &  \\  poor individual  &       &   &   &       &   &   & \\     accuracy algorithms   &       &   &   &       &   &   & \\       \hline \end{tabular} \label{table:table6} \end{table*} \end{document}

I have posted this code before. i now want to add two multi columns upside down to the same table jus like i have marked before and after table picture to make my point clear    Here is my code of picture no 1 i posted  \documentclass[journal]{IEEEtran}  \usepackage{multicol}  \usepackage{multirow}  \begin{table*}  \settowidth\rotheadsize{DIMENSIONS}  \renewcommand\multirowsetup{\centering}  \renewcommand{\arraystretch}{1.5}      \centering  \caption{Extreme Learning Machine(ELM) with kernel classifier accuracy of   combine reduced feature vectors whose individual classifier accuracy was low}      \begin{tabular}{|l|l| c |C{2.5cm}| c |C{2.5cm}|C{2cm}|C{2.5cm}|}      \hline   Algorithm      & Dimension          &  \multirow{6}{*}{\rothead{ADD THESE\\ DIMENSIONS}}              & Total after Adding Dimensions                  & Classifier                      & Dimension Reduction Technique                          & Reduced Dimension                              & Accuracy  \\       \cline{1-2} \cline{4-8}  LBP & 4D    &                  & \multirow{5}{=}{4D + 6D + 4D\\ + 3D + 4D = 21D}                      & ELM                          & \multirow{5}{=}{Eigenvalue as Dimension Estimator,                                            PCA as Dimension Reduction}                             & \multirow{5}{=}{21 dimensions reduced to   dimensions}                                 & \multirow{5}{=}{Combine accuracy of 9  dimensional                                                   reduced Feature Vector is  again 80\%}    \\      \cline{1-2} \cline{5-5}  RGLBP         & 6D    &   &   & ELM   &   &   &   \\      \cline{1-2} \cline{5-5}  BDIP   & 4D    &   &   & ELM   &   &   &   \\      \cline{1-2} \cline{5-5}  HOG      & 3D    &   &   & ELM   &   &   &   \\      \cline{1-2} \cline{5-5}  Combine and reduced     & 4D    &   &   & ELM   &   &   &    \\    fv of poor individual  &       &   &   &       &   &   &  \\     accuracy algorithms   &       &   &   &       &   &   & \\        \hline  \end{tabular}  \label{table:table6}  \end{table*}


I have a question I have been pondering for a while.  What is the best way of keeping line breaks to a MySQL db and handle the escapes so that the query doesn't fail.  I came up with a function to do this but I am not sure this is the right way to handle the string.  function nl2br2 ($string){     $sqlescapes = array("'", ";");     $string = str_replace($sqlescapes, "", $string);      return str_replace( "\n", '
', $string );  }   This function will replace PHP line breaks and replace them with
 so html can recognise them if I use mysqli_real_escape_string it removes the line break and this is the predicament.  Are there any other functions I could utilise, as the above removes grammar from the string?

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 have searched for an answer for my problem in a lot of "undefined reference to" posts, but none of them seem to be the issue here. I'll try to explain. I have a class "Disnovo" with two functions that use Eigen: Eigen::Matrix4f calculateTransform(Eigen::Matrix<float,6,1> chi); Eigen::Matrix<float,6,1> calculateTwist(Eigen::Matrix4f T); I wanted to use that function with double in addition to float, so I tried overloading but it didn't work. Then I tried using templates, and created the following: template <typename Derived> Eigen::Matrix<typename Derived::Scalar, -1, -1> calculateTransform(const Eigen::MatrixBase<Derived>& chi);  This is located in a .h file, while the definition is in a .cpp file: template <typename Derived> Eigen::Matrix<typename Derived::Scalar, -1, -1> Disnovo::calculateTransform(const Eigen::MatrixBase<Derived>& chi) {     Matrix<typename Derived::Scalar, 4, 4> T, Tchi;     Tchi.setZero();      Tchi(0,1) = -chi(5); Tchi(0,2) =  chi(4);     Tchi(1,0) =  chi(5); Tchi(1,2) = -chi(3);     Tchi(2,0) = -chi(4); Tchi(2,1) =  chi(3);      T = Tchi.exp();     T(0,3) = chi(0); T(1,3) = chi(1); T(2,3) = chi(2);      return T; }  This works perfectly, so I tried to do the same with the other function: // .h  template <typename Derived>     Eigen::Matrix<typename Derived::Scalar, -1, -1> calculateTwist(const Eigen::MatrixBase<Derived>& T);  // .cpp template <typename Derived> Eigen::Matrix<typename Derived::Scalar, -1, -1> Disnovo::calculateTwist(const Eigen::MatrixBase<Derived>& T) {     Matrix<typename Derived::Scalar, 6, 1> chi;     Matrix<typename Derived::Scalar, 4, 4> Tchi;      chi(0) = T(0,3);    chi(1) = T(1,3);    chi(2) = T(2,3);     chi(3) = Tchi(2,1); chi(4) = Tchi(0,2); chi(5) = Tchi(1,0);      return chi; }  But this is creating undefined reference to `Eigen::Matrix<Eigen::Matrix<float, 4, 4, 0, 4, 4>::Scalar, -1, -1, 0, -1, -1> Disnovo::calculateTwist<Eigen::Matrix<float, 4, 4, 0, 4, 4> >(Eigen::MatrixBase<Eigen::Matrix<float, 4, 4, 0, 4, 4> > const&)'  when linking (I think). What am I doing wrong here? Why does one of them work and the other does not?

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


I am a fan of  8 Ball Pool on Miniclip. Also I have dual boot OSs, so I play on Windows, but whenever I open it in Ubuntu in Chromium browser, I always get a white screen like this:    I even tried playing it on Facebook, but it is still like that.  I have installed Flash Player or plugin,. but I'm not sure it got installed or whatever. Can someone please tell me any way to fix it?

I have the newest flash player, but I cant get it to work on the website pogo.com. it says: Your Adobe Flash Player is out of date  No need to panic, you just need the latest version of Adobe Flash Player to play this game. Please visit Adobe.com to update your version now.  Update Adobe Flash Player  Still experiencing issues? Check out Adobe's Flash Troubleshooting Guide  I am very new to linux, so this is probably an easy fix, but still need help! So please help! :)


How would I use regex to extract the string between the third and fourth underscore in the following example: 123456-AB_ABC_ABC123_Extract This_ABCDEFG  I tried ^(?:[^_]+_){3}([^_]+)  But it seems to return all of the characters up to the fourth underscore instead of starting after the third underscore like I imagined. What'd I miss there? Thanks!

I want to match a portion of a string using a  and then access that parenthesized substring:  var myString = "something format_abc"; // I want "abc"  var arr = /(?:^|\s)format_(.*?)(?:\s|$)/.exec(myString);  console.log(arr);     // Prints: [" format_abc", "abc"] .. so far so good. console.log(arr[1]);  // Prints: undefined  (???) console.log(arr[0]);  // Prints: format_undefined (!!!)   What am I doing wrong?    I've discovered that there was nothing wrong with the regular expression code above: the actual string which I was testing against was this:  "date format_%A"   Reporting that "%A" is undefined seems a very strange behaviour, but it is not directly related to this question, so I've opened a new one, .    The issue was that console.log takes its parameters like a printf statement, and since the string I was logging ("%A") had a special value, it was trying to find the value of the next parameter.


I installed Ubuntu 14.04 LTS alongside windows 7. I have 4 partitions on windows 7. I had a 73 GB partition which I could have used in it's entirety for installing ubuntu. Unfortunately, when I chose to install ubuntu alongside windows 7 it only took 30 GB of that partition and I didn't re-size it.  My question is - Will I be able to access windows partitions and install software on them if I wish to do so from my ubuntu login? Will 30 GB be sufficient to install all updates/packages/software? I plan to do some side dev projects on the machine.  Are these instructions safe for re-sizing the windows partition and assigning it to ubuntu -  or are there better instructions available?

Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers.  Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions).  Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space.  How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions?


How can I find out the size of a file I opened with an application written in C ?  I would like to know the size, because I want to put the content of the loaded file into a string, which I allocate using malloc(). Just writing malloc(10000*sizeof(char)); is IMHO a bad idea.

How can I figure out the size of a file, in bytes?  #include <stdio.h>  unsigned int fsize(char* file){   //what goes here? }


In which situations should I use fish-eye effect? I own a Canon Power sx510hs which is an advanced point and shoot camera. It has fish eye effect which distorts an image spherically. Other than having funny photo sessions with my kin, I would like to know what are the main utility of this effect and how I can produce quality photographs using this effect.

I have a variety of lenses in my camera kit. One that I do not have, and has me curious, is a fisheye lens. I mostly understand what it does: it captures an image with distortion similar to what you see through a door's peephole.  Given the distortion, are there any particular types of shots for which a fisheye lens is useful?


I'm studying electronic communications engineering, specifically, signal processing, and I always find difficulty when studying stochastic processes subject.   Could you recommend me a student-friendly stochastic processes book that covers fundamentals of stochastic processes for electronic engineering studies?     I've approximately one semester to study for this then I'll take Stochastic Signal Processing lecture which is built on this fundamentals and continue with estimation theory.   I have Probability, Random Variables, and Stochastic Processes, Papoulis 3rd edition book but I didn't find it very helpful. Is newer versions are better?  I'll do a self-study so I'm looking for the book which explains topics clearly. Also, if you have, related video lecture recommendations may be very helpful.  This lecture is very fundamental for my studies so I want to grab a well understanding on this subject.  Thanks

I would like to find a book that introduces me gently to the subject of stochastic processes without sacrificing mathematical rigor. It would be great if the book has lots of examples and that the book is designed for undergraduates. Just like how there are rigorous undergraduate abstract algebra books (I am thinking of GAllian's contemporary modern algebra here).   I already studied measure theory, and prob. theory.  Thank you.


I've never even heard the term "Goodness of Fit" in my class. I looked through the textbook and can't find it there either.  What exactly is "goodness of fit"? Is there a formula to calculate it?

I am having trouble understanding the concept of 'goodness of fit' w.r.t linear regression. The name suggests that the goodness of fit test is used to determine how well a model fits the data.  But the linear model is already the 'best' fit since we have minimized the sum of the squared error terms. Why do we need to test 'goodness of fit' again? We know it is a good fit because we minimized the sum of the squared errors.


So I feel stupid for asking this, but I can't figure this out. I haven't taken algebra for about 8 years, so doing this is kind of fuzzy.  Just started Calc 1 and we're finding limits. $$\lim_{x \to 9} \frac{x - 9}{\sqrt{x} - 3} .$$  I try to do some algebra to rationalize the denominator, but everything I do gets me to the limit equaling either $2$ or $3$. Which makes me think I don't understant rationalizing the denominator.  What I get is: $$\lim_{x \to 9} \frac{x\sqrt{x} - 9\sqrt{x}}{x - 3\sqrt{x}}$$  This is where I'm confusing myself. I don't know where to go to simplify from here. And I still can't do direct substitution because it will equal $\frac{0}{0}$.

How do you evaluate the limit of  $$\lim_{x \to 9} \frac {x-9} {\sqrt{x} - 3}$$  by first principle? I was thinking of this way to evaluate but it seems to evaluate to $\frac {0} {0}$.  $$\lim_{x \to 9} \frac {x-9} {\sqrt{x} - 3} = \frac{\lim_{x \to 9} (x-9) }{\lim_{x \to 9}  {\sqrt{x} - 3}}$$  I mentioned that the limits do not exist because the function is not continuous at $ x=9$. Any idea on how to solve this question?


I installed 12.04 Desktop because I want the option to run Unity in the future, but I PREFER to work headless via SSH.  I changed the following in /etc/default/grub:  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"   changed to:   GRUB_CMDLINE_LINUX_DEFAULT="text"   Rebooted and still get the graphical Unity interface  changed the above to:  GRUB_CMDLINE_LINUX_DEFAULT=""   Rebooted and again, no love -- still get the Unity interface.  I see that /boot/grub/grub.cfg is generated automagically by grub-mkconfig using templates /etc/grub.d and /etc/default.  I saw that my first option in grub still read thusly:  menuentry 'Ubuntu, with Linux 3.5.0-27-generic' --class ubuntu --class gnu-linux --class gnu --class os {     gfxmode $linux_gfx_mode     insmod gzio     insmod part_msdos     insmod ext2     set root='(hd0,msdos1)'     search --no-floppy --fs-uuid --set=root c40e42d6-6e01-4abf-b2e3-e46132dcfa0a    linux   /vmlinuz-3.5.0-27-generic root=UUID=3a07789f-f0b4-4123-a26a-6f245ef9054e ro   quiet splash $vt_handoffeneric     echo    'Loading Linux 3.5.0-27-generic ...'     linux   /vmlinuz-3.5.0-27-generic root=UUID=3a07789f-f0b4-4123-a26a-6f245ef9054e ro recovery nomodeset      echo    'Loading initial ramdisk ...'     initrd  /initrd.img-3.5.0-27-generic  }   Note that it still reads 'quiet splash' above (single quotes mine).  So I ran grub-mkconfig to see if that was needed to re-build grub.cfg from /etc/default/grub, but even after running that, 'quiet splash' persists.  Can anyone advise on where I'm going wrong?  I just want my bash...  Thanks.

Is it possible to disable X at boot time? I'm setting up a server so it would be nice if it wouldn't load the graphical interface every time I boot.


I often find SO answers in Safari and I would like to open them in the App by tapping a button on the site, like Twitter does at least on iOS.   Would it be possible to implement such a feature please?  By pressing the button with a phone you open the user site in the Twitter App:

Can we add functionality to the mobile site to view the page in the SE iOS app? It could be through  or a link at the bottom where the download link is.        I really don't care which, but right now there's just no way to do it.


This question seems to be asked already some years ago:   Then it was said the option is not important, no OpenID  in GitHub, etc.  However now, with the end of OpenID support, it would be extremely convenient for many users of Stack Overflow particularly.

I've seen sign in methods using  as an authentication provider, for example : (AWS Cloud9)        Is it possible to authenticate into Stack Exchange using this method? At the moment there's other methods such as OpenID, Google, Yahoo and Facebook, but it would be interesting to also have the GitHub authentication.


Could someone take a look at the wacom issues? aparently I am not the only one having these issues but on my Fujitsu T4220 & T4210 tablet PCs I can't unplug the wacom to reset it. Everything works great if not a bit slow; but when it comes back on from suspend the OS says there is no tablet device, I have to reboot for it to see the wacom tablet again. It is slightly annoying and has caused me to reconsider going back to ubuntu 12.04 (wacom works perfect on there) or switching to another distro after using ubuntu for several years now.

The tablet functionality stops working after I wake my Lenovo Tablet from sleep mode (closing & opening lit). The error message is "Tablet Serial Wacom Tablet (Lenovo X201) removed" (screenshot: ). In the system settings under input devices it states that "No tablet device is detected". Only a restart helps and the touch screen works again.  This error appeared only after upgrading from Kubuntu 12.04 to 14.04. In 12.04 the same error message appeared after waking from sleep mode, but then another followed that the tablet was activated again and it worked properly. Any ideas how this could be fixed?


Is there any plans to integrate the "Achievements" drop down with the mobile app? It's the one visual indicator I really, really miss when using the iOS app.   The only idea I've had as to how to achieve this is to have the current "Inbox" icon serving a dual purpose for both the "Inbox" and "Achievements".. with maybe a green indicator highlighting Achievements, and a red indicator highlighting Inbox messages.  Upon clicking the icon, the user would be able to toggle between a list of "Achievements" and a list of "Inbox" items.

It'd be nice to see reputation updates in the app, as we get on both the desktop and mobile sites.  Mock-up of how this would look:        Other possible icon states:        While I understand reputation is shown in the feed, it's a bit unwieldy, and has no notification.   With this feature implemented, the feed could arguably lose both reputation and inbox items, and be left with the interesting questions that fill it up. This would make for a much more consistent UX across app and desktop.


I'm trying to work with precise values in Blender and I found this weird thing where the Dimensions tool only shows the full decimal point value when selected.  Now I know I could change the unit scale on the scene properties, but what if I want to work in meters, but in a given object I want to be able to check dimensions more precisely (in millimeters for instance)     Why does it happen? Is there an option to change this?  Thanks.

How can I get more digits in the user interface for modeling.  Of course we can scale up the scene always, but that is just annoying, I like to work in millimeters for example which is possible with the Metric settings in blender, but the UI only shows floating point up to 3 digits?  Is there any way of improving this? Especially the scale in the transform property tab only shows 3 digits, that's annoying :-)


I have a Jasper template that consumes JSON data. I have a JsonQL as language for the datasource. The template compiles fine locally and generates a PDF preview.  But when we try to execute this on the server (standalone app using jasperreports 6.4.0 as a dependency), I get this error message:     org.springframework.web.util.NestedServletException: Handler processing failed; nested exception is java.lang.NoClassDefFoundError: antlr/TokenStream       at org.springframework.web.servlet.DispatcherServlet.triggerAfterCompletionWithError(DispatcherServlet.java:1302)       at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:977)       at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)       at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:968)   I have checked the pom file for net.sf.jasperreports 6.4.0 and it has this as a dependency:      <dependency>         <groupId>antlr</groupId>         <artifactId>antlr</artifactId>         <version>2.7.5</version>         <optional>true</optional>     </dependency>   So I can't figure out why I get a NoClassDefFoundError for antrl.TokenStream. I found some posts online that say use Antlr 2.7.7 but this is the Jasper engine pom so I can't overwrite it easily. Could there be any other reason?  We have lots of other templates that work just fine. This is the first one that uses JsonQL. Is that a factor?

I am getting a NoClassDefFoundError when I run my Java application.  What is typically the cause of this?


Hi everyone I know that this subject has been posted many times but none of them work for me . So I need to store some arabic data in particular table but when I send it and explore it within phpmyadmin I found something like this &#1575 i try to add the meta charset=utf-8 in head and add accept-charset='utf-8' in the form  but still no difference  here's the code that i use it to connect to my database     $conect=new PDO("mysql:host=$host;dbname=$datab;charset=utf8;connection collation: utf8_general_ci",$user,$pass); $conect->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); $sql="INSERT INTO botola_team(name,nameabbreviation,team_url,year_of_ta2sis,President,coach,name_field,pic_of_team,logo,pic_field) VALUES ('$name','$nameabrev','$teamurl','$ta2sis','$president','$coach','$namefield','$teampic','$logo','$teampic')"; $conect->exec($sql);

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


Prove that the following polynomial $$p(x) = \sum_{k=0}^n x^k$$ has no multiple roots  Hint: consider the polynomial $(x-1)\times \sum_{k=0}^n x^k$  I have tried finding the derivative of the polynomial and trying to reach a contradiction by supposing there is a root such that p(x) = p'(x) = 0 but I can't reach any conclusions. The hint leads me nowhere, I don't know how to use that information  Thanks in advance

Prove $f=1+x+x^2+x^3+\cdots+x^n$ has no multiple roots.  My attempt:  Consider the polynomial $g=(x-1)(1+x+x^2+x^3+\cdots+x^n)$  As $f\mid g, g$ all the roots of $f$ are roots of $g$.  This means I have to prove the statement:  If $c$ is a multiple root of $f \Longrightarrow c$ is multiple a root of $g$.  Equivalently:  If $c$ is not a multiple root of $g \Longrightarrow c$ is not a multiple root of $f$.  I'll try to prove this last statement:  Suppose $\exists c$ such that $c$ is a multiple root of $g$, then   $$g(c)=0 \implies g'(c)=0$$  $$ g=(x-1)(1+x+\cdots+x^n) \implies  g'=nx^n $$ $$ g'(c)=nc^n=0 \implies c=0 $$ But  $$ g(0)\neq 0 $$ And we've found the contradiction: $\not \exists c: g(c)=g'(c)=0$. Then $f$ has no multiple roots.  Is this correct?   Also: Assuming this is correct, is it possible to prove $\sum_{k=0}^n \frac {x^n}{n!} $ has no multiple roots in a similar manner?


Are there any single-plug (not "powerstrip"-style) adapters that can work for Italy, France, the UK, and Switzerland? It seems very cumbersome to have to pack 4 types of adapters.   'European' outlet, used in continental EU-countries   Outlet used in island countries of EU (Britain, Malta, Cyprus, Ireland)   Swiss outlet  (Image sources - )  Update: Both the answers provide what I was looking for, but given the cost and the lack of product reviews on those type of items, I decided against it. I was looking for an adapter from US to Country XYZ that would work for all countries in Europe.

You can buy travel adapters for AC power plugs, but do powerstrips exist that accommodate different international power plugs in one unit? When travelling and collaborating in an international environment, power cords turn into a spaghetti of cords.   It would be so convenient if powerstrips exist that accommodate for example a US, a British, French/German power cord on one unit, but I have not found one and I have searched extensively.   Do they exist at all, or do international laws prohibit such a device?


On Ubuntu 14.04 is there a way to directly trace an application in real time? This maybe on here but I could not find a page in search with "Google" or "site search" that I could say applied. I did find info on tracing Ubuntu crashes, as in the operating system, not usable on a Application crash as far as I can tell. (I may be wrong?)  I'm having a problem mainly with Firefox(Occasional(One or none for hours.) to almost continuous(Every blipping few minutes.).) but it very very occasionally affects Gthumb, what happens is the App(s) crashes(Completely ends, Firefox opens restart window with info that is simply worthless. Addins and Firefox version. No blippin help there.).  Never has there been any problem with the crash affecting Ubuntu its self(Stays working perfectly.).  As far as I can tell every other application I have loaded works same as always.  Just Firefox to a major extent, and Gthumb to a very minor extent.  By the way Chrome, Ubuntu software center, Synaptic, Gdebi, Terminal, Update, all work accessing the web normally(Ubuntu software takes forever to get application images but this is "normal" as far as I have read.)  I have tried Firefox with and without addins in safe mode, no change.  I have tried three different versions of Firefox and even a portable version, no change.  I have used Synaptics package manager's fix broken packages, no change. I have updated several times no change.  As for crash logs I did a lot of looking searching and found no info on crash logs the closest I got was about var and logs but I don't have files listed, not sure if they were for my version of Linux, and looking around I can't find any in /var/logs or /var/crash which were the places I figured to find a crash log.  What I think caused the problem was an update on Dec 23rd.  Since I don't update constantly I'm not sure when the update item came out that caused the problem.(See bellow.)  Anyway I figure the only way to figure out what is going on is to trace the crash as it happens in some way.  Of course someone mite have an idea from the updates as to what would affect Firefox mostly?  In the three screen shots bellow you can see the updates.     In answer to question is this a duplicate of "How do I know which file a program is trying to access?", Its not because the problem in that link is some package is missing and they need to find it and install or update the package, while my problem is a package(?) Firefox(and Gthumb) accesses crashes the program(s) randomly.  So they are not the same problem but the info in that Post maybe useful in tracking things down.  I'm still looking for the answer and will update when I find one.  I'm going threw a big mess from lsof -c firefox.  So far I found Firefox does have logs, they are in a hidden directory under your home directory, there are a bunch of different ones, so far I have three file types I need to find readers for as they are not just text .dmp .extra .mozlz4.

I have a program which I am trying to run, however when I run it; it just complains that it can't find a particular file.  However I have no idea which folder it is trying to find this particular file in. I have a copy of the required file, I just need to know which folder to copy it too.  Is there any way to show in real time which files are being accessed or which files are trying and failing to be accessed?  I am using Ext4 filesystem if that helps.  Thanks


Interpretation of solutions with negative energies was such that charge, rather then probability, density was assumed. When inserting charge of a particle negative sign is then obviously due to charge.  How did the equation know this? Maybe it is a stupid question, but how did the equation know our convention regarding different kinds of charges?

I am totally a beginner in QFT, here's the problem that I got: for the real scalar fields, are there any elementary particles descriped by them. If so, how to understand the negative probability problem?


I have a script in a folder:  /path/to/my/script.sh   I need this script to run every time the system starts (even if no one logs in to the system). What do I need to do in order to make this happen?

How can I run scripts automatically when Ubuntu starts up so I don't have to run them manually after startup?


When I open some application it says Google play services it says "Google play services which some of your applications rely n do not support or device"..what should I do about it?

I've installed , but it does not start, instead I get the following error:     Google Play Services, which some of your applications rely on, is not supported by your device.   I don't know what does this mean and how can I solve this issue to use the application. I'm using Chinese phone AMOI N 821 android 4.1.1. I live in Russia.  What should I do?


I have HP 18 AIO Desktop, which has inbuilt web cam. How can I set an external Webcam (Logitech C170) as a default cam from command ? Is there any way, Please help me.  Cheese webcam booth or other software can do this but I wan to do it on system based so that it will be work on all webcam related software.  Thanks!  Birendra

I am looking for a way to disable the webcam that is integrated into my laptop. The webcam is using uvcvideo module but I do not want to blacklist it since it is also being used by an external webcam I have.  Is there any way of disabling the device itself without touching the modules list?  This is how the webcams are listed by lsusb. The first one is an integrated one (It is identified by some apps as BisonCam NB Pro), the second one is the external Logitech C525:  Bus 002 Device 004: ID 5986:0361 Acer, Inc  Bus 003 Device 002: ID 046d:0826 Logitech, Inc.    I have already checked BIOS - there is no way of disabling the webcam from there. Besides I would love to learn how to disable the device by ID anyway.  Thanks!


Could someone provide a wrong clime and  its wrong proof by induction so that only the first step be wrong?

Question: Can you provide an example of a claim where the base case holds but there is a subtle flaw in the inductive step that leads to a fake proof of a clearly erroneous result? [Note: Please do not answer with the very common  example.]  Comment: Sometimes inductive arguments can lead to controversial conclusions, such as the ,  and a host of other paradoxes. However, I am interested in examples of a more mathematical nature (as opposed to linguistic) where the inductive argument is subtly flawed and leads to erroneous conclusions.   Note: If you provide an answer, please do so in a way similar to how current answers are displayed (gray out the flaw so people can be challenged to discover it).


I just notice that my grub has two entries, one Ubuntu and another one Ubuntu (lowlatency), and both of them are loading the same low-latency-kernel. The Ubuntu entry should load the generic kernel not the low latency one, right?  Here is the output of update-grub, is detecting the lowlatency kernel twice.   Sourcing file `/etc/default/grub' Sourcing file `/etc/default/grub.d/init-select.cfg' Generating grub configuration file ... Found linux image: /boot/vmlinuz-5.0.0-19-lowlatency Found initrd image: /boot/initrd.img-5.0.0-19-lowlatency Found linux image: /boot/vmlinuz-5.0.0-19-lowlatency Found initrd image: /boot/initrd.img-5.0.0-19-lowlatency Found linux image: /boot/vmlinuz-5.0.0-19-generic Found initrd image: /boot/initrd.img-5.0.0-19-generic Found linux image: /boot/vmlinuz-5.0.0-17-lowlatency Found initrd image: /boot/initrd.img-5.0.0-17-lowlatency Found linux image: /boot/vmlinuz-5.0.0-17-generic Found initrd image: /boot/initrd.img-5.0.0-17-generic Found linux image: /boot/vmlinuz-5.0.0-16-lowlatency Found initrd image: /boot/initrd.img-5.0.0-16-lowlatency Found linux image: /boot/vmlinuz-5.0.0-16-generic Found initrd image: /boot/initrd.img-5.0.0-16-generic Found linux image: /boot/vmlinuz-5.0.0-15-generic Found initrd image: /boot/initrd.img-5.0.0-15-generic done   I really want to be able to load the generic kernel on the "Ubuntu" entry.  I'm using Kubuntu with the UbuntuStudio lowlatency kernel installed.

In a fresh ubuntu-studio 14.04 install sudo apt-get install linux-generic.  Then the grub-mkconfig will give you a menu as such   Ubuntu (lowlatency) Ubuntu Advanced options for Ubuntu   A quick look with the 'e' key will show that both Ubuntu (lowlatency) and Ubuntu point to    linux   /boot/vmlinuz-3.13.0-24-lowlatency   A work around is you can select the desired kernel in  the 'Advanced option for Ubuntu' menu.  How can we fix /etc/grub.d/09_lowlatency and /etc/grub.d/10_linux so that they don't select the same default kernel?  Relevant menuentry in /boot/grub/grub.cfg from /etc/grub.d/09_lowlatency  menuentry 'Ubuntu (lowlatency)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-0f6e1051-cf9f-4299-b691-76d0d8c532d1' { recordfail         load_video         gfxmode $linux_gfx_mode         insmod gzio         insmod part_msdos         insmod ext2         set root='hd0,msdos1'         if [ x$feature_platform_search_hint = xy ]; then           search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  0f6e1051-cf9f-4299-b691-76d0d8c532d1         else           search --no-floppy --fs-uuid --set=root 0f6e1051-cf9f-4299-b691-76d0d8c532d1         fi         linux   /boot/vmlinuz-3.13.0-24-lowlatency root=UUID=0f6e1051-cf9f-4299-b691-76d0d8c532d1 ro   quiet splash $vt_handoff         initrd  /boot/initrd.img-3.13.0-24-lowlatency }   And the menu entry in /boot/grub/grub.cfg from /etc/grub.d/10_linux  menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-0f6e1051-cf9f-4299-b691-76d0d8c532d1' {         recordfail         load_video         gfxmode $linux_gfx_mode         insmod gzio         insmod part_msdos         insmod ext2         set root='hd0,msdos1'         if [ x$feature_platform_search_hint = xy ]; then           search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  0f6e1051-cf9f-4299-b691-76d0d8c532d1         else           search --no-floppy --fs-uuid --set=root 0f6e1051-cf9f-4299-b691-76d0d8c532d1         fi         linux   /boot/vmlinuz-3.13.0-24-lowlatency root=UUID=0f6e1051-cf9f-4299-b691-76d0d8c532d1 ro  quiet splash $vt_handoff         initrd  /boot/initrd.img-3.13.0-24-lowlatency }   Yes I assure you I have a normal kernel installed:  $ ls -l /vmlinuz* lrwxrwxrwx 1 root root 30 May  5 20:37 /vmlinuz -> boot/vmlinuz-3.13.0-24-generic lrwxrwxrwx 1 root root 33 May  2 20:25 /vmlinuz.old -> boot/vmlinuz-3.13.0-24-lowlatency


I have a SQL Server table with ~100 columns including the columns Id and CreationDate. Due to a bad constraint in its initial design, there are now many duplicate rows (i.e. rows whose values are identical across ALL columns).   Can you suggest a script to remove those duplicate rows?   Also, what would be a script to select all distinct Ids with the latest CreationDate?  Thanks

What is the best way to remove duplicate rows from a fairly large SQL Server table (i.e. 300,000+ rows)?  The rows, of course, will not be perfect duplicates because of the existence of the RowID identity field.  MyTable  RowID int not null identity(1,1) primary key, Col1 varchar(20) not null, Col2 varchar(2048) not null, Col3 tinyint not null


Apologies for the term "rogue" document, by that I mean a pdf file that has been downloaded (not created by myself first), then opened in Illustrator.  The problem I'm getting is that when I try to open up the colour swatches from the top left, I get nothing but none or registration black as fill choices:    Is there a way to load my standard pallet back in this document or have certain setting disabled this?

When opening a new image from a PNG file in Illustrator as the background for my artboard to trace over I am not able to select any color swatches the only available options are [none] and [registration].  I have black and white available for gradients but thats it. I have checked the color settings and they are set to RGB.  Has anyone come across this before, I'm hoping to either force colors or else find a way to add images from a file into the artboard as when I create a new document the standard colors are all present.  The weird thing is I have just traced round a photo and I cannot remember having this problem in the past!


I have a spare 92mm case fan rated 12V and ~600mA I've used to build a solder fume extractor. When I was prototyping it, I tested the fan with a 12V 2.5A AC adapter and it worked fine, ran at full speed, and was drawing 450-460 mA. I didn't want to tie up that AC adapter with this device, so I purchased a 12V 1A AC adapter to dedicate to the project.  I finished the project today and plugged in the new 12V 1A adapter. The fan would not run at full speed, and the speed surged up and down about once per second. I checked the adapter and it is putting out 12V, and I do have the polarity correct, and the fan is rotating the correct direction.  I tested it again with the larger adapter, and it is still drawing around 450mA, and the fan runs at full speed with that adapter.  I can't imagine what might be going wrong here. Do I have a bad adapter, or am I missing something?  Edit: I've figured it out. Turns out I had another 12V 1A adapter in an old Radio Shack kit, and it gave me the same poor result. I tried again with the 2.5A adapter, and this time checked the startup current: approximately 1.5A. The 1A adapters just can't supply enough current to get the motor to start up to full speed. I just need a higher capacity adapter.

I would like to connect an electric toothbrush motor (Braun Oral-B Type 4729) directly to external power supply. So far I have been trying at least 3 different DC power supply unit with appropriate voltage (1-5 V) but nothing happened. However motor works perfectly fine when connected just to a regular battery (AA, 1.5V)...what is happening? The only guess I have is some impedance mismatch between the source and the motor...can anyone confirm this and/or provide any solution how to connect this motor to regular DC power unit? Thank you very much!


Find $\displaystyle \int_0^\infty \dfrac{\ln(x)}{1+x^2} \, dx$.   Do I change the limits of integration and add the two here?

Find $\displaystyle \int_{0}^{\infty} \dfrac{\ln(x)}{1+x^2}dx$.   How should I change the limits of integration to evaluate this?


Can anyone suggest me some good reference books where different properties and characteristics of matrices are explained in details and in lucid language?

I have been working in R for a bit and have been faced with things like PCA, SVD, QR decompositions and many such linear algebra results (when inspecting estimating weighted regressions and such) so I wanted to know if anyone has a recommendation on a good comprehensive linear algebra book which is not too theoretical but is mathematically rigorous and covers all of these such topics.


Below is a screenshot for Macintosh HD drive storage.    It shows that I have 82.47 GB storage for "Other". How to delete and free up this space?  I checked ~/Downloads and ~/Desktop, both are less than 2 GB.  I also emptied out ~/Library/Cache and ~/Library/Cache folders.  I am running OS X 10.11.2.

Every few days I get notices on my MacBook that it's running or run out of hard drive space. Curiously, restarting the computer will enable me to recover gigabytes of space (this past time, it was able to recover about 2.2GB). However, I can't identify anything in my personal activity that consumed that space.  It's possible that it's a rogue iTunes podcast or a huge software update that my Mac is automatically downloading - would either of these reclaim the space upon a restart?  One possibility that I can think of is that FileVault has some sort of disk leak, allocating but not freeing files. Does this make sense? Is there a tool that I can run to determine where this space is going? Assuming it is FileVault, should I try to disable it? What's the best way to turn of FileVault on a nearly full computer?


I have this simple code   $(function() {     $('.add').click(function() {         $('.accounts').append(`

           <input id="nme" type="text" class="validate">           Name...

         `);     });     $('.account').click(function() {         alert();     }); });   My problem is, when I click on an element with a .add class, a new div.account element is created and when I click on the element(.account), no alert is shown. There is one div.account element that exists initially before clicking the add button. It shows an alert but not others generated by the script. Where I'm I going wrong or what should I do?

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 have a package installed (xcp-xapi) which is prone to a bug. The fix is very simple (only a couple of lines in the code) so what I do is the following:  apt-get source xcp-xapi   Then I find the source file to apply the fix and then I run again  apt-get -b source xcp-xapi   This will produce some .deb files that I install using  dpkg -i *.deb   Now the problem is that every time I try to run an apt-get upgrade, apt tries to fetch the packages from the repositories. I guess this can be fixed using pinning, but I cannot find the proper configuration to put in high priority the packages I compiled on my own.  So the question is how can I configure pinning to put the following already installed packages on higher priority than any existing in the repositories?  # apt-cache policy xcp-networkd xcp-v6d xcp-xapi xcp-xapi-debug xcp-networkd:   Installed: 1.3.2-5ubuntu0.1   Candidate: 1.3.2-5ubuntu0.1   Version table:      1.3.2-5ubuntu0.1 0         500 http://ftp.uninett.no/ubuntu/ precise-updates/universe amd64 Packages         500 http://security.ubuntu.com/ubuntu/ precise-security/universe amd64 Packages  *** 1.3.2-5ubuntu0.1 0         100 /var/lib/dpkg/status      1.3.2-5 0         500 http://ftp.uninett.no/ubuntu/ precise/universe amd64 Packages xcp-v6d:   Installed: 1.3.2-5ubuntu0.1   Candidate: 1.3.2-5ubuntu0.1   Version table:      1.3.2-5ubuntu0.1 0         500 http://ftp.uninett.no/ubuntu/ precise-updates/universe amd64 Packages         500 http://security.ubuntu.com/ubuntu/ precise-security/universe amd64 Packages  *** 1.3.2-5ubuntu0.1 0         100 /var/lib/dpkg/status      1.3.2-5 0         500 http://ftp.uninett.no/ubuntu/ precise/universe amd64 Packages xcp-xapi:   Installed: 1.3.2-5ubuntu0.1   Candidate: 1.3.2-5ubuntu0.1   Version table:      1.3.2-5ubuntu0.1 0         500 http://ftp.uninett.no/ubuntu/ precise-updates/universe amd64 Packages         500 http://security.ubuntu.com/ubuntu/ precise-security/universe amd64 Packages  *** 1.3.2-5ubuntu0.1 0         100 /var/lib/dpkg/status      1.3.2-5 0         500 http://ftp.uninett.no/ubuntu/ precise/universe amd64 Packages xcp-xapi-debug:   Installed: 1.3.2-5ubuntu0.1   Candidate: 1.3.2-5ubuntu0.1   Version table:      1.3.2-5ubuntu0.1 0         500 http://ftp.uninett.no/ubuntu/ precise-updates/universe amd64 Packages         500 http://security.ubuntu.com/ubuntu/ precise-security/universe amd64 Packages  *** 1.3.2-5ubuntu0.1 0         100 /var/lib/dpkg/status      1.3.2-5 0         500 http://ftp.uninett.no/ubuntu/ precise/universe amd64 Packages

Because of  I'd like to prevent apt-get upgrade and Update Manager from updating the "libgtk2.0-0" package.   How can this be achieved?


In R, the  function prints "the correlation matrix of the estimated parameters". I previously assumed this was simply the correlation matrix of those variables in the raw data - such that, for example, predictors x1 and x2 would have the same correlation with each other in that matrix, whether the model being fit was "y ~ x1 + x2" or "y ~ x1 + x2 + x3 + x4". However, it seems I am wrong about this, as the correlations in this matrix seem to change depending on what else is in the model. (It's not an issue of NA rows being excluded - there are no NAs in this dataset). What is the distinction between the "correlation matrix of the estimated parameters" and the correlation matrix of original data columns?

I have fitted a model using glm.  In the summary(model) I get a correlation matrix, but I don't understand how the correlations are calculated and what the interpretation is.  The documentation says "The estimated correlations of the estimated coefficients", but the estimated coefficients are real numbers (one-dimensional) so the correlation does not make sense.


When I launch emacs from ZSH, it works as desired.  Specifically, it sees that my HOME directory is /Users/myname/Dropbox, so it looks for .emacs.d there.  Unfortunately, when double-click the emacs icon in my Applications folder (/Applications/Emacs), this behavior is not present.  Launching with Alfred gives the same behavior as double-clicking the icon.  Is there any way I can make the GUI-launch more closely mimic the command-line launch?  I guess another way to ask this question is -- from what environment is the application launching when I double-click the icon or launch with Alfred?

I need to set a number of Environment variables that can be seen by GUI apps (i.e. Xcode). When running from a terminal this is trivial and is simply a case of adding a. number of export commands to my .bash_profile e.g.  export BOOST_INCLUDE=~/boost/boost-XXXX/boost   Unfortunately GUI apps do not see values set in .bash_profile. I am using Catalina and it appears that Apple modifies the mechanism every time MacOs is updated. Many online guides are out of date....  This article:  suggests that launchctl should do what I need but even the following simple example does not work:  In a terminal:  /bin/launchctl setenv FOO BAR   Then close the terminal and open a new one  Check the value:  echo $FOO   The output should be   BAR   But it is unset. Note it is also unset in the original terminal so I am not convinced that the command /bin/launchctl setenv FOO BAR is doing anything.  Note: This is about setting the environment variable for GUI apps NOT just for the terminal.


I am currently learning about objects in javascript.  I have encountered behaviour I didn't expect and I want to confirm if I am seeing what I should be seeing or if I have made a mistake somewhere.  var a = 1; var b = a; b++; console.log(a); // 1 (As expected) console.log(b); // 2  var a = 'string'; var b = a; b += 'ier'; console.log(a); // string (As expected) console.log(b); // stringier  var a = {}; var b = a; b['testValue'] = 'test'; console.log(a); // {testValue = 'test'} (Wait... what?!) console.log(b); // {testValue = 'test'}     Added:  I've just tried the same experiment with an array and I see the array is exhibiting the same behaviour as the object (perhaps to be expected, given that arrays are objects in Javascript)  var a = []; var b = a; b[0] = 'test'; console.log(a); // ['test'] (Hmmm... again!) console.log(b); // ['test']     Why are the object and the array behaving differently from the number and the string?  Why is var b only referencing var a rather than duplicating it?

The primitive types (number, string, etc.) are passed by value, but objects are unknown, because they can be both passed-by-value (in case we consider that a variable holding an object is in fact a reference to the object) and passed-by-reference (when we consider that the variable to the object holds the object itself).  Although it doesn't really matter at the end, I want to know what is the correct way to present the arguments passing conventions. Is there an excerpt from JavaScript specification, which defines what should be the semantics regarding this?


There are ways to gain multiple actions in a turn through for example the fighters action surge, but I've found nothing in respect to bonus actions.

Other than having the Haste spell cast on you and using the action provided to use something that requires a bonus action are there any other ways to gain additional bonus actions in 5e?


I have a common typescript class with some functions.  When I do  this.selected = Object.assign({} as AssignedTestType, newTestType);  the selected instance does not own that functions which are in the type AssignedTestType.  How can I make a 'deep' copy with object.assign? or any alternative method?

What is the most efficient way to clone a JavaScript object? I've seen obj = eval(uneval(o)); being used, but . I've done things like obj = JSON.parse(JSON.stringify(o)); but question the efficiency.  I've also seen recursive copying functions with various flaws.  I'm surprised no canonical solution exists.


Yesterday someone started downvoting my answers. I ignored the downvotes knowing that the system will reverse them, and the system did reverse some of those downvotes.  Today I flagged one of my answers, chose in need of moderator intervention, and explained my problem. I stated who it was. since I know who it is, then few hours later, the downvotes came again.  What should I do in this case, since this person keeps coming again and again? And from now on, how will I know if the downvote against my answer is a legit downvote not someone just against me?  Downvotes from Yesterday    Downvotes from Today

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


I have a list that contains people's names in one column and their company's names in a second column. At the top of each column there is a label, i.e "Name" for column A, "Company" for column B.  The way a program I want to use works is to read data from a master list in one column, and it differentiates the type of data contained in the first column using second column, like this:  The ultimate goal is to have this data pulled automatically from an outside source, which is stored on one tab. There will then be another tab containing this master list, one column containing people's names and various company names, and a second column with the first column's data type (i.e 'Person' or 'Company', as pictured above) right next to it. So far I have been able to populate individual columns in the second tab by using Sheet's "QUERY" function, `QUERY('Importer'!A2:A)`    which allows the column to update very nicely every time the other tab is updated from the outside source, the problem is that because I don't know ahead of time how long the referenced column is going to be, I can't add a second 'QUERY' function to pull data from another column below it. Any tips on how to solve this would be much appreciated. Thanks!

I have data that looks like this:  Id | Loc1 | Loc2 | Loc3 | Loc4 ---+------+------+------+----- 1  | NY   | CA   | TX   | IL 2  | WA   | OR   | NH   | RI   And I want to convert it to this:  Id | LocNum | Loc ---+--------+---- 1  |   1    | NY 1  |   2    | CA 1  |   3    | TX 1  |   4    | IL 2  |   1    | WA 2  |   2    | OR 2  |   3    | NH 2  |   4    | RI   What's the easiest way to do this in Excel 2007?


There is some kind of interplanetary conflict going on between different human factions (aliens may or may not be involved). As a relatively minor plot point a group of or all humans have lost the ability to appreciate or comprehend music through a virus or other disease. I believe it changed their DNA so the (loss) trait was inherited.

A few years ago I read an excellent sf book about nanobots that went out of control. In the book they were used for weather control, when they went amok the scientists threw in yet another bunch of nanites and so on, until Earth became uninhabitable, teeming with nanites, I remember the weather also became cold. The planet still could be visited but when they lost cloaking the nanites would attack.   Also, some humans in the book merged with nanites, they could behave benevolently but I forgot the plot too. I only remember fragments of this book, I would like to read it again in English. (loaned a long time ago from a library here in Sweden but they closed the library).   I only know that it was written by an Anglo-American contemporary SF writer, probably 30-55 y.o.


Please note, this is purely for educational purposes only and I ALWAYS protect my SQL queries no matter what they are used for, it would be a majorly bad idea not to! This question specifically focuses on $_GET requests and NOT $_POST requests.  So I have recently experienced a brute force attack on one of my accounts and thought it was probably for the best to check my scripts in case I had missed anything (Luckily the attack was unsuccessful).   I came across this script from one of my older accounts:  if(isset($_GET['del'])){     $user_id = $_SESSION['userid'];     $id_pho = $_GET['del'];     $sql = "DELETE FROM new_user_favourites WHERE `user_id` = '$user_id' AND `photo_id` = '$id_pho'";     $conn->query($sql); }   I thought before I protected this script, that I would give it a bit of a test and found that even if I attempted to cause a problem to this script, using the URL, that the URL added encoded spaces %20 or speech marks %27 and these would not allow the script to process any further code?  For example, I tested:  mysite.co.uk?del='; UPDATE new_users SET account_type='1' WHERE email_address='test@test.com   Which should have sent:  $sql = "DELETE FROM new_user_favourites WHERE `user_id` = '' AND `photo_id` = ''; UPDATE new_users SET account_type='1' WHERE email_address='test@test.com'";   That would have given that user admin privileges to my site. Although because of the encoding, the result in the URL shows as:  mysite.co.uk?del=%27;%20UPDATE%20new_users%20SET%20account_type=%271%27%20WHERE%20email_address=%27test@test.com   And so the query would process like this, and fail:  $sql = "DELETE FROM new_user_favourites WHERE `user_id` = '' AND `photo_id` = '%27;%20UPDATE%20new_users%20SET%20account_type=%271%27%20WHERE%20email_address=%27test@test.com'";   Could this mean that my query is already protected from this kind of attack? Or is there a way around this for people who would wish to destroy my website? I've taken a look online for information about this but there doesn't seem to be anything?

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?


Consider, for a moment, a worthwhile technology like .  If you want to use their API, you might have a question you would ask on .  If you had a question about the Dropbox app that you install on your PC to automatically synchronize files to and from the cloud, you'd want to ask it at .  If you were having an issue with the web interface, a question on  wouldn't go amiss.  Let's not forget there's a very nice Android app you might ask about on .  Oh, right. There's an iOS app too, which you'd ask about at .  That's how we do things around here, and it's all good. (I'm much better equipped to help someone with the Android app or the web interface than with the iOS app, for instance.) And, inevitably, there will be some cross-contamination: a question about the PC app on Web Apps, for instance.  Wouldn't it be nice to be able to cross-link those tags to all of those other sites? And to do so in a standardized way?  Yes, of course, tag wikis can be edited to include links to those other sites. But it's not standardized, so it will look different on every site, and it's a bit of effort.  So I propose a system similar to synonyms. Call it "cross-site synonyms" or something. Where someone can propose that a tag on one Stack Exchange site is the counterpart of a tag on another Stack Exchange site. Heck, even allow people to vote on those links like synonyms.

I think there's an unintended motivation for users to post questions to higher-traffic Stack Exchange sites rather than their more specific or appropriate lower-traffic ones.  I think I have a solution.  What motivated this suggestion for me was that I am confident that if users were to post Android design questions to  beta and/or , that they would likely not be noticed by the appropriate audience compared to the vast army of Android experts here on Stack Overflow.    There are plenty of Android questions on SO that really should be on one or both of the aforementioned sites.  Presently there is little motivation for users to start questions like this on the appropriate site.  Is there something we could do to cross-pollinate related sites?  For instance, what if we let certain tags span certain sites?  Obviously the selection would be controlled by high-reputation users.   There could also be a feature to show (or explicitly hide) certain questions from other sites regardless of the tags.  This could be controlled by lower-reputation users than the global tag since it wouldn't have much statistical impact.  For instance, the android-layout tag could by default span sites, but OPs and other users could eliminate from the Graphic Design site questions that are of a purely technical nature.  Users interested in Android tagged questions would see related questions on design and UE sites--whether they are searching, posting, or viewing a question through the related items.  This would help eliminate cross-site duplicates, and encourage people to post on the correct site in the first place.   For related question lists and search results, there could even be a specific cross-site icon  next to an off-site question to show that it's from UX, for example.


Column F is a list of constants. Each cell is named. I want to insert the name of each cell in Column F into an adjacent cell in Column E. For example F9 is named "FeetPerMeter" and has a value of 3.28084. I want the value of E9 to be the text string  "FeetPerMeter".

I need a formula to use cell address and return the cell defined name, i.e.  =INDIRECT(ADDRESS(ROW(),COLUMN(),1,,"SHEET 001"))   I need this ADDRESS(ROW(),COLUMN() to refer to the current cell defined name i.e. "sales" and not $A$1


I am wondering if there is a way to output a single image file that contains two layers: one with the rendered image, and one with the composited image.  This would be useful when importing renders in Photoshop, or in order to have two options for each image when exporting an animation. It could also be cool to have the composited layer and the rendered image when importing the sequence into an editing program (one would then have two footage layers instead of one and can blend/fade between the two etc).  Here's a file I experimented with, I exported to .tif which I think supports layers, but in Photoshop there was just one image.

I am having an issue with EXR file export that I did not encounter in previous versions of Blender. I used to be able to render a render layer with all its passes and get all the passes included with the render layer with the EXR export; the problem I am finding now is that I am not able to "pack" the passes with the EXR file (see graphic below). I am working with "standard" EXR, as I understand that the EXR multilayer is for multiple file handling (packing all the image files into a single container), but I may be wrong.    In the screenshot, the graphic is an EXR saved from the rendered layer; you can see in the screenshot how the "extra" passes from the render layer has been ignored by the graphic and only shows the standard image, z and alpha passes. I found this issue for the first time with Blender 2.71; and maybe with Cycles; in the past I have never had an issue with EXR export.  Am I missing something? I hope EXRs still work with Blender, I wouldn't know how to composite without such invaluable aid. Sorry if this question has already been answered somewhere; I have really searched the site for information on EXR but I could not find an answer to my issue.


I am using a Huawei y210d, and when I try to install any app, after downloading I get an insufficient space warning. Can anyone tell me how I can solve this problem?

Every time I go to install a new app, I get the message "Insufficient storage", and an unable to install anything!  I am using Samsung GT19060 my internal memory is 8GB. I have not downloaded anything but anytime I try to download something it will tell me low memory space.


As far as my MacBook is concerned, I have 3 Wi-Fi Networks in my house, with different names (it is actually one network, with 2 repeaters). I move around the house and frequently use the 2 repeaters in particular. Quite often I lose connection to one of the repeaters, and my laptop will reconnect, but possibly to the farther repeater with a weaker signal, depending on the order of preference set in advanced network preferences. Because this signal may be quite weak, I may lose Internet connection using this Wi-Fi repeater, but my laptop will not try to connect to the repeater with the stronger signal.  The only way to get round this is to continually change my network preferences whenever I move around the house, which is very annoying.  Is there any way I can get my laptop to have no preference between the two repeaters, and to connect to which ever has the stronger signal?  This is not a duplicate question because the other question is asking how to enable an order of preference on an iphone and this question is asking how to disable it on a Macbook. Not surprisingly, none of the answers there answer my question.

I have two Wi-Fi networks in my house, one at one end of the house and one at the other.  While signals crossing from one side of the house are usually audible on the other side, they are generally fairly weak and quite nearly unusable - something in the house's construction attenuates signals traveling through certain walls.  So, to enable good connectivity while roaming the house, I have to have my Wi-Fi clients configured for both networks.  This works fine on PCs where I can configure both networks and set a priority order, so that the system prefers the network closest to its normal location and should only roam when its usual network gets too weak.  However, I cannot find a way to set this priority in iOS.  This results in some devices occasionally connecting to the farther AP, despite being in their regular spot where they should prefer the closer one.  How can I customize the roaming preferences for Wi-Fi networks on the iOS devices?  I at least want to assign a "preferred" network for each, but would also like to know if there's a way to set a "roaming threshold" - a point at which the device should choose to change APs, versus remaining on the current one.  I'm pretty sure all my iOS devices are running iOS 5 or higher.


Let's assume that I've contacted professors in the United States and referred to them appropriately as "Dr. Smith" or "Professor Smith" based on their having attained a Ph.D.   If they respond to me informally, should I continue to address them formally? If so, for how long?

When writing letter to an academic professor (not necessarily from student to professor), what is the appropriate way to address his/her title?  I have seen in letters using  Dear Prof. X even when the addressee is not a full professor  Dear Dr. X though, knowing that the addressee is a full professor  Dear Mr/Mrs X though, knowing that s/he has an academic title


I have noticed recently, that random questions appear with light orange (debatable) background colour like :        I could not make out why is this happening.  Any significance of this?  For assistance :  My favourite tags are :

answered my question "why some questions has yellow background" but it raised another question. I am viewing questions under my interesting tag then what is the need for yellow background because all questions fall under my interesting tag.


Let $A$ be a Noetherian ring, $M$ be a finitely generated $A$-module, and $\mathfrak{p}$ be a prime ideal in $A$. I want to ask how to prove that $M\otimes A_\mathfrak{p}/\mathfrak{p}A_\mathfrak{p}\neq0$ if and only if $\text{Ann}(M)\subseteq\mathfrak{p}$. Thanks.

Let $A$ be a commutative ring with 1, set $V(\frak a)=$ the set of prime ideals of $A$ that contains $\mathfrak a$, and write $\operatorname{Supp}(M)$ for the support of the $A$-module $M$. We always have $\operatorname{Supp}(M)\subseteq V(\operatorname{Ann} M)$; if $M$ is finitely generated then the other inclusion also holds. Assume now $M$ is finitely generated. It is ok to show that if $M_{\frak p}=0$ then $\operatorname{Ann} M\cap A\setminus\frak p\ne\varnothing$, I was just wondering if the following procedure for showing this inclusion is flawed:  Suppose $\frak p$ contains $\operatorname{Ann} M$. Since $M$ is finitely generated we have the equality $(\operatorname{Ann} M)_{\frak p}=\operatorname{ Ann} (M_p)$, hence the annihilator of $M_{\frak p}$ is contained in maximal ideal of $A_{\frak p}$ and is therefore different from (1), so $M_{\frak p}\ne0$.


Question!     Show that the pair of positive integers $n$ and $n+2$ are twin primes if and only if $$4[(n-1)! + 1] + n = 0 \ (\text{mod} \ n(n+2)),$$ where $n$ does not equal $1$.

The Wiki page on  says     The pair $(m, m+2)$ is twin prime, iff $4((m-1)! + 1) \equiv -m \pmod {m(m+2)}$.   This is obviously connected to Wilson's Theorem. Can anybody provide a proof for that, along the lines of thought given here, ?


In the first book, Hagrid says that Lily and James Potter were both head girl and head boy.   But Lupin says that he was the prefect, so how could James Potter become the head boy? This has never happened before, right? Percy and Bill were both prefects and then head boy.

I was under the impression that the Head Boy and Head Girl were always chosen from among the prefects, however...  "No one would have made me a prefect, I spent too much time in detention with James. Lupin was the good boy, he got the badge." — Sirius Black to Harry, Order of the Phoenix  So James Potter was not a prefect. But...  "Now, yer mum an' dad were as good a witch an' wizard as I ever knew. Head Boy an' Girl at Hogwarts in their day!" — Hagrid to Harry, Sorcerer's Stone  How does one get to be Head Boy without first being a prefect? If James' time in detention disqualified him from being a prefect, why did it not disqualify him from being Head Boy?


I'm looking at adding a unique identifier field for my assets that will have a prefix of the record type and then a following 4 numbers.   Office Equipment   Abbreviation of OE  Remote Equipment   Abbreviation of RE    So we would have OE-0001 and RE-0001 as two unique records, in the same field, same record.  I know we can use something like A-{0000} to specify A as the prefix and {0000} as the minimum numbers to show. But replacing the A is the issue?   Can this be done / how?

On the Task object, I have to create a field "Barcode Number"( Bar_Code_Number__c), which starting from a specific value 68992001 and for every created task on any object increment to one, when the Task subject is " PTT Dispatch Task" only. For other task subject , it should be blank. Also, the users can also edit this field if they want. But the next task creation will follow the regular increment number ( and not from the one what the user has changed). Can you plz suggest how to achieve it. Thanks  I tried a workflow rule but did not succeeded.  As per the WF I created, the criteria as Task subject as " PTT Dispatch Task" , and formula as below, and first time i inputted the number above first number here. But i think this is not the correct way.


The word tough is pronounced /tʌf/. The word though has a completely different pronunciation, that is /ðəʊ/.    Is there a reason why the latter would not be pronounced /ðʌf/?

There are cough, tough, bough, through, and though (and "hiccough", if you're not from the U.S.); each of which has a different pronunciation for the ending "-ough".  Why is this?  Edit for clarification: I'm trying to figure out why cough is spelled with an "-ough", if it's pronounced with an "-off".  And then tough, pronounced "tuff".  Why is that not spelled "tuff"?  Bough, through, and though should be spelled "bow", "thrue" (or "thru"), and "thoe".  Where did "-ough" come from?  And then hiccough.  Since that derives from cough, it should be pronounced "hickoff", but it isn't.


I have an xypic diagram that I want to have within the body of text (article class). The .tex file looks like this at the relevant place:  \section{A Framework}  What we have now is a picture that looks like the following:  \xymatrixcolsep{3pc} \begin{figure} \centerline{\xymatrix{ *+[F-]\txt{`The World'}\ar[d] & & *+[F-]{\text{Models}} \ar[d]\\ *+[F-]\txt{Propositions $p, ...$}\ar[d] & & *+[F-]{\txt{Sentences $\phi, ...$}} \ar[d]\\ *+[F-]\txt{Informal Theory $T_I$} \ar[d] \ar[rr]_*+[F-:<8pt>]{\small{\emph{Formalisation}}}  & & *+[F-]{\txt{Formal Theory $T_F$}} \ar[d]\\ *+[F-]{\text{Informal Beliefs}}\ar[d] &  & *+[F-]{\txt{Formal Properties}} \ar[d] \\ *+[F-,]{\bf{e.g. Semantic Realism}} \ar@{-}@/^6pc/[uuuu] \ar@{.}[rr] & & *+[F-,]{\bf{e.g. Categoricity}} \ar@{-}@/_6pc/[uuuu] & \\ }} \end{figure}  There are such things as informal mathematical theories, consisting of purely mathematical propositions in natural language, which are in turn about mathematical reality (or, `the world') in some sense.   I want the diagram to be where it seems to be placed in the code, but when I typeset it just sticks to the top of the page, before the section 'A Framework' even begins. How do I move it? Can't seem to find any advice.

Is there any package or a method to force LaTeX to keep floating environments like table and figure closer to where they are declared?


I remember a thread here in the SciFi Stack Exchange about the longest sci-fi series. Someone mention a standalone Heinlein book that seemed to somehow include all other books ever written in its story. Does anybody know which book is that?

I'm trying to remember the name of a story, I think the author was Larry Niven, but it might possibly be from Heinlein's "Future History" series (but a check of the stories included in the Future History indicates it's not in there), about a man whose commute is stopped because a criminal has to be 'adjusted'.  In this case, the criminal was a hit-and-run driver who left his victim untreated on the roadside, and was sentenced to suffer in the same manner. So his leg was carefully broken and he was left, untreated and in pain, on the side of the road in the same place for an hour. All the time ambulances were standing by, and every effort was made to ensure that the criminal did not suffer unduly - but that he did suffer, in a manner as close to the suffering he inflicted on his victim.


I am using this command to do some magic for my personal use:  osascript -e \'tell application "Terminal" to do script   Is it possible to precisely define the width and height of the popup Terminal window?  If not, is there anyway I can do it after it's opened? (Precisely adjust its size value)

So that I could resize the window to a certain size from within Terminal.


Which packages can be using for writing authors names and affiliation?                      thank you in advance

The standard titlepage is quite simple. I am looking for a very  and need help customizing my title page.  It should match the  classicthesis doctoral thesis template  Below a minimal working example:   \documentclass[12pt,a4paper,footinclude=true,twoside,headinclude=true]{scrbook} \XeTeXinputencoding iso-8859-1 \usepackage[marginparsep=8pt,left=3.5cm,right=3.5cm,top=3cm,bottom=3cm]{geometry}  \usepackage[parts,pdfspacing,dottedtoc]{classicthesis}    \frontmatter  \begin{document}     \pagestyle{scrheadings}        %this is the place to set up my cover sheet.       %*******************************************************      % Abstract     %*******************************************************    %\renewcommand{\abstractname}{Abstract}    \pdfbookmark[1]{Résumé}{Résumé}   \begingroup    \let\clearpage\relax    \let\cleardoublepage\relax    \let\cleardoublepage\relax       \chapter{Résumé}     Résumé de la thèse en français\dots      \vfill      \chapter*{Summary}   Résumé de la thèse en anglais\dots    \endgroup             \vfill     \end{document}


I got this problem where my JS-functions won't work/run after i rebuild my HTML page with some new values from my XML-file. To not make this post too long i gathered the HTML/CSS in jsfiddle:  (I'ts not fully functional since i don't know how to add xml/ajax stuff to jsfiddle)  Basically, there is an image and a checkbox, when the checkbox is checked then the image gets the class "markedImg" which have a opacity value of 1. This doesn't work when i try to rebuild the html with values from an XML file.  I do the request like this:  function doRequest(target) {     if (XMLHttpRequest) {         request = new XMLHttpRequest();     } else if (ActiveXObject) {         request = new ActiveXObject("Microsoft.XMLHTTP");     } else {         return false;     }     request.open("GET", target, true);     request.send(null);     request.onreadystatechange = function () {         if ((request.readyState === 4) && (request.status === 200)) {             createHTML(request.responseXML);         }     }; }   Sending "target" parameter from an addeventlistener  categoryMenu.addEventListener("change", function () {     if (categoryMenu.value === "Flower") {         doRequest("categories/imgcat0.xml");     }     if (categoryMenu.value === "Buttefly") {         doRequest("categories/imgcat1.xml");     } });   And then i run the function "createHTML", which rebuilds the html using the values from XML files  function createHTML (XMLcode) { var imgURL = XMLcode.getElementsByTagName("image"); var title = XMLcode.querySelector("title"); var html = ""; imgForm.innerHTML = "";  html += '
' + title.firstChild.data + '
';  for (var i = 0; i < imgURL.length; i++) {     html += '
';     html += '<input type="checkbox" align="middle">';     html += '
';     html += '
';     html += '
'; } imgForm.innerHTML = html; }   And so far everything works, but when i add the function to add the "markedImg" class, it doesn't run on the newly created HTML elements. Nothing happens with this function basically. The function itself works, which you can see in the jsfiddle example, but it's after you change the category and the "doRequest" functions runs that it doesn't work.  checks.forEach(function (checkbox, index) { checkbox.onchange = function () {     if (this.checked) {         unmarkedImg[index].classList.add("markedImg");     } else {         unmarkedImg[index].classList.remove("markedImg");     } }; });   The XML is very simple, just a title and source to the images:  <imagecategory>     <title>Butterfly</title>     <image>         <url>http://i.imgur.com/LY1Mq8k.jpg</url>     </image> </imagecategory>   Sorry if the post got a bit long.. Hopefully this makes sense to someone. Thanks!

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.


How can we position the coin so that it fits the text? So far as you see the coin is a bit upper than the median line of the text.    .coins_plans {    font-size: 1rem;     margin-top: 0;     margin-bottom: 30px;     text-align: center; }  .coins_plans img {  width: 30px;  height: 30px; }
all  s you got till now.
     Here is what I want:

Why won't vertical-align: middle work?  And yet, vertical-align: top does work.   span{   vertical-align: middle; }
      Doesn't work.


I am currently looking at some Marine Protected Areas (MPAs) in Madagascar, and am trying to work out the percentage reef cover inside an MPA boundary. For example (in the picture below), I have the outline layer for the Ankivonjy MPA, and then another layer for reef cover. So my questions is: would it be possible to intersect the two layers, and then determine the proportion of the MPA that is covered by reef. If so, please could you explain how this is done.   The end goal is to be able to say that "coral reef comprises x% of the area within the Ankivonjy MPA".  NB: I am doing these analyses in QGIS.

In this project, I have three polygons, see the image below  'Polygons_From', includes input attributes, i.g. "Value_1", "Value_2", "Value_3", and $area for each quadrate (on the image there are two types of them). 'Polygons_To' polygons for which new values "Value_1_new", "Value_2_new", "Value_3_new" need to be defined 'Border' defines an area where the calculation should be done.   My task is to transfer values from 'Polygons_From' into 'Polygons_To' based on a certain aspect/ratio. Of course, I can simply achieve it with the 'Union' function as was suggested in . It uses $area-factor, but perhaps there are better approaches that will lead me to a much more efficient output? So, I am asking for a recommendation regarding the technique/workflow that can be applied in QGIS 2.18. Shall I consider only $area or there are some other criteria? Moreover, I looking forward to finding some papers that may improve my general understanding of the methodology.  References:


We are trying to place multiple DIVs side by side.  Very easy, just use FLOAT or INLINE-BLOCK.  The issue with both is you cannot center the data inside the DIV vertically.  Any help would be appreciated!  Needs to be done without a framework.     Some have suggested this article, but this does not take in to account two or more div's next to each other.    Option 1:

     Option 2:

I have a div with two images and an h1. All of them need to be vertically aligned within the div, next to each other. One of the images needs to be absolute positioned within the div. What is the CSS needed for this to work on all common browsers?

testing...


Prove that $X=\{(x,y) :x\text{ is rational or }y\text{ is rational}\}$ is path connected.   So for every $(x,y)$ in $X$, I need to find a continuous function $f$ on $[a,b]$ such that $f(a)=x$ and $f(b)=y$.   Trying to think about suitable functions, maybe one which sends everything to nearest rational. But don't think such a function exists.

How do I show that $X = \left\{ (x,y) \in \mathbb{R}^2 \mid x \in \mathbb{Q}\text{ or }y \in \mathbb{Q}\right\}$ is path connected?    Note that $X$ is a topological space with subspace topology $\tau = \left\{ U \cap X \mid U\text{ is open in }\mathbb{R}^2\right\}$.  I only know two things (with respect to path connectedness):   A topological space $X$ is path connected iff for every $p,q \in X$, there is a continuous function $f: [a,b] \to X$ with $f(a)=p$ and $f(b) = q$.    Continuity $f$ is defined as for every open set in $X$, its preimage is open in $[a,b]$ (with subspace topology induced by $\mathbb{R}$ (with standard topology) )   Suppose $X$ and $Y$ are two topological spaces and $f: X \to Y$ is a continuous surjection. If $X$ is path connected, then $Y$ is path connected.


Let $\vec { A } = a \hat { i } + b \hat { j } + c \hat { k }$. Is $\frac { 1 } { \vec { A } }$ a vector or not, and if it is, then what are its components?"

I get the physical significance of vector addition & subtraction. But I don't understand what do dot & cross products mean?   More specifically,    Why is it that dot product of vectors $\vec{A}$ and $\vec{B}$ is defined as $AB\cos\theta$? Why is it that cross product of vectors $\vec{A}$ and $\vec{B}$ is defined as $AB\sin\theta$, times a unit vector determined from the right-hand rule?   To me, both these formulae seem to be arbitrarily defined (although, I know that it definitely wouldn't be the case).   If the cross product could be defined arbitrarily, why can't we define division of vectors? What's wrong with that? Why can't vectors be divided?


When I load chat on my iPad, it loads in the middle of the chat page. From there, I can scroll a little way in either direction, but I can't scroll all the way to the bottom or all the way to the top of the page.  This means I can't reach the input box at the bottom. I'm also unsure about whether there are supposed to be buttons at the top that I can see.  iOS 8 point something.

I'm using Safari on an iPhone 6, iOS 8.4 (yes, it's time to upgrade, but then how would we find these fun bugs?).  In the new mobile chat, the bottom part of the content area is often outside the bounds of the device and can't be scrolled to.  This is what I normally see when opening a room list: . And this is what happens if I take a screenshot while still touching the screen after scrolling to the bottom of the list: . (The second I let go, the list "bounces" back to what you see in the first screenshot.)  Entering a room typically looks like this: .  So, it appears that this behaviour occurs when Safari is still showing the browser navigation controls. There's no apparent way to dismiss those controls - scrolling or tapping anywhere on the screen doesn't do it - and they don't disappear on their own. I've been able to make it go away sometimes by scrolling until the input message box is in view, but then the top part of the page goes AWOL and there's no bringing it back: .  If I reply to a specific message, the input box at the bottom sticks around like it should, and the messages scroll fine behind it... but the header disappears completely (similar to , but without even a sliver of blue at the top).


Use the identity $\sec x=\frac{\cos x}{1-\sin^2x}$ to prove that the integral of $\sec x$ equals $\frac12\ln\frac{1+\sin x}{1-\sin x}$. I tried to manipulate it but nothing seems to work. Help.

Question says it all, how can I verify the following?  $$\int\sec x\ dx=\frac12 \ln \left|\frac{1+\sin x}{1-\sin x}\right| + C$$


Not a dupe, my proposal is not about a contact request to the author, it is about comments, like comments below any SE post (which are visible and are reactable by all the community!).  It would be a very useful feature, because it could enhance the discussion, by creating a community around the data SE.  What is maybe more important: we could contact the query authors about bugs and problems, or unclear side-effects, or any other.

I guess I'm asking for comments, with subsequent notifications, to be added to queries in SEDE, so we can point out [fixes]  to flawed queries, especially when [the query]  has a comment in it explaining the problem.


I am looking for a particular short story consisting entirely of rejection letter correspondence.  Each formally dated paragraph is from either the aspiring writer or the publisher's rejection. The story ends with the aspiring writer compiling all the rejections into a single volume and submitting that volume itself as a work. The publisher replies that that too has been rejected as unoriginal....

I can't remember the name of the story, and couldn't find anything on Google searches either.  The story is about a science fiction writer whose story gets rejected by the publisher because it's word-by-word identical to another story published years ago. The writer then writes another story only to find out that the same author also published this story around the same time as the other one.  Our writer then writes a story about a man who uses a time machine to read other people's work in the future and then publishes it in his time. Only to find out that this story was also published by the same guy years ago.  The story I'm trying to find out was in the form of letter correspondence between the writer and the publisher.  So, does anyone know its title?


I was writing a bubblesort in C# and ran into this problem. Below are my classes and after the classes I will describe my problem.  using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks;  namespace BubbleSort { class Person {     public String FirstName { get; set; }     public String LastName {get; set;}     public String PhoneNumber { get; set; }     public Person(String firstName, String lastName)     {         FirstName = firstName;         LastName = lastName;      } } }    using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.IO; using System.Collections;  namespace BubbleSort { class ListProvider {     //Class Variables     private StreamReader fileReader;     //private List<Person> test;      #region Properties     public List<Person> TheList     {         get { return TheList; }         set { TheList = value; }     }     #endregion      /// <summary>     /// I wish C# had a Scanner class :/. How different are these languages really?     /// </summary>     /// <param name="fileName"></param>     public ListProvider(string fileName)     {        // test = new List<Person>();                         using (fileReader = new StreamReader(fileName))             {                 String line = "";                 while (fileReader.Peek() != -1)                 {                     line = fileReader.ReadLine();                     String[] nameArray = line.Split(' ');                      TheList.Add(new Person(nameArray[0], nameArray[1]));                     //test.Add(new Person(nameArray[0], nameArray[1]));                 }             }         }   } }   using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks;  namespace BubbleSort { class Program {     static void Main(string[] args)     {         ListProvider listProvider = new ListProvider("C:\\Users\\JC Boss\\Desktop\\Career\\Programming Practice\\BubbleSort\\BubbleSort\\names.txt");         foreach (Person person in listProvider.TheList)         {             Console.WriteLine(person.FirstName + " " + person.LastName);         }     }   Okay. So when I try and add a new Person to this list, I get a stack overflow exception. Now, if I were to uncomment the List variable test, and add to that. It would work fine, and would throw no error. Why is this happening? I looked around but could not see why this would happen to a property?      } }

I know java and would normally put in getter/setter methods. I am interested in doing it in C# with the following code, but it throws a StackOverflow exception. What am I doing wrong?  Calling Code  c.firstName = "a";   Property Code    public String firstName; {     get     {         return firstName;     }     set     {         firstName = value;     } }


I created an empty react project and I only added a materializecss for styles.

  I added a styles for my blocks. .App {   height: 100vh; }  .category__list {   margin: 0;   height: 100%; }  .page-footer {     padding: 0; }  Why my block App and the block category__list have the same height? And I have a scroll and my footer not see without use the scroll. As I see it, the category__list block should set all free space and my footer haven't to be outside the display. For example

I am working on a web application where I want the content to fill the height of the entire screen.  The page has a header, which contains a logo, and account information. This could be an arbitrary height. I want the content div to fill the rest of the page to the bottom.  I have a header div and a content div. At the moment I am using a table for the layout like so:  CSS and HTML    #page {     height: 100%; width: 100% }  #tdcontent {     height: 100%; }  #content {     overflow: auto; /* or overflow: hidden; */ }

...

...

     The entire height of the page is filled, and no scrolling is required.  For anything inside the content div, setting top: 0; will put it right underneath the header. Sometimes the content will be a real table, with its height set to 100%. Putting header inside content will not allow this to work.  Is there a way to achieve the same effect without using the table?  Update:  Elements inside the content div will have heights set to percentages as well. So something at 100% inside the div will fill it to the bottom. As will two elements at 50%.  Update 2:  For instance, if the header takes up 20% of the screen's height, a table specified at 50% inside #content would take up 40% of the screen space. So far, wrapping the entire thing in a table is the only thing that works.