When I search for the following in meta:  intitle:1 should   I get results with the word should in the question title, but I also get results that don't have should in the title.  intitle:1 "should" or intitle:1 +should  I get no results. Anyone know how you get only results with a certain word in the title?  Related:

I'm trying to search for questions that have specific words in their titles using the  search feature, but it seems that it does not return any search results.  Using this feature, I tried to search for questions on Stack Overflow with , but this search query returns no results.  Is it still possible to filter the search results based on words in question titles?


Is it fine/safe if I have multiple threads running in parallel and each thread uses the same HashMap instance? The HashMap object will only be used to read data. There will be no writing data to the HashMap in any of the threads.  To be clear, the HashMap instance is a member of a base class and I will be calling the background threads in its subclasses. Those threads will then refer to the HashMap object.

There is a case where a map will be constructed, and once it is initialized, it will never be modified again.  It will however, be accessed (via get(key) only) from multiple threads.  Is it safe to use a java.util.HashMap in this way?  (Currently, I'm happily using a java.util.concurrent.ConcurrentHashMap, and have no measured need to improve performance, but am simply curious if a simple HashMap would suffice.  Hence, this question is not "Which one should I use?" nor is it a performance question.  Rather, the question is "Would it be safe?")


I'm Creating A New Discord Bot For My Server When I Close The Console I Want The Application To Run A Little Bit Of Code  Reminder I Cannot Reference Windows.Forms Because I'm Using A .Net Core Console Application  How Would I Do This? As I'm Not Familiar With Consoles Quite Yet

I have a console application that contains quite a lot of threads.  There are threads that monitor certain conditions and terminate the program if they are true.  This termination can happen at any time.  I need an event that can be triggered when the program is closing so that I can cleanup all of the other threads and close all file handles and connections properly.  I'm not sure if there is one already built into the .NET framework, so I'm asking before I write my own.  I was wondering if there was an event along the lines of:  MyConsoleProgram.OnExit += CleanupBeforeExit;


First of all I'm a complete noob when it comes to QGIS so maybe thats the reason why I cannot find anything on this on google (or is this due to the 2.8.1 compatebility issue?).  My issue is that when I create the heatmap the location of the heatmap is off compared to the data. I've checked the CRS and all match (project CRS, data CRS AND the heatmap CRS). I've redone several tutorials several times and started several times from scratch but somehow it keeps giving me the data on the wrong location :-(.

I noticed that the heatmap calculation on the new upgrade version of qgis is given the raster map without any coordinate system.   Have you got the same problem?


The book was about a man who would be surgically altered to investigate different planets, and live with the alien beings on them. He would learn about them, and their social/linguistic behaviours. On one planet he became a being that would curl into a ball and roll. On another, he became some type of lizard-type thing that had a pyramidal structure sticking out from it, the purpose of which he did not know. It's not a recent novel, I probably read it 25 years ago. There were at least two or three different life forms he was altered to be. At the time I was reading a lot of Heinlein, Pohl, and Poul.

I'm trying to remember the title of a story i read where a man is hired to research primitive aliens by being altered surgically or genetically to live as one of them. The only catch is he can never go back to being human. After several different body changes, the main character is told he can be modified one last time, and he can pick what he wants. He chooses to become a being with the best aspects of all the different aliens he experienced.


I'm aware I can use awk to parse on multiple delims, but that spawns subprocesses. I wanted to know if compound/nested bash parameter expansion is possible.  I have PDFs in a directory named like "Px_MM-DD-YY_SSSSSSSSSS.pdf" where:   "Px" means "Page x", and x has no leading zeroes. "MM" corresponds to the two digit month, with a leading zero if applicable. "DD" corresponds to the two digit day, with a leading zero if applicable. "YY" corresponds to the two digit year, with a leading zero if applicable. "SSSSSSSSSS" corresponds to the ten digit epoch time the PDF was created, which allows me to keep PDF page revisions.   I have a for loop (I'll drop "-mtime" when I'm ready to operate on all the PDFs)  for file in $(find -type f -iname '*_??????????.pdf' -mtime -1) do     echo $file done   where I want to echo only the epoch time.   I can use this for loop   for file in $(find -type f -iname '*_??????????.pdf' -mtime -1) do     echo ${file##*_} done   and for the file named like "./P14_07-21-18_4X_1532144458.pdf", "1532144458.pdf" is echoed to the screen.  I can use this for loop   for file in $(find -type f -iname '*_??????????.pdf' -mtime -1) do     echo ${file%.*} done   and for the file named like "./P14_07-21-18_4X_1532144458.pdf", "./P14_07-21-18_4X_1532144458" is echoed to the screen.  If I replace the echo ... line with any of the formats below  echo ${${file##*_}:0:10} echo ${(${file##*_}):0:10} echo ${${file##*_}%.*} echo ${{file%.*}##_} echo ${${file%.*}##_}   I get -bash: ... : bad substitution. Am I not getting the syntax right or is nested/compound bash expansion not possible?

I'm trying to use the Bash parameter expansions to modify the output of a command substitution or another parameter expansion. The following nested expansions work quite well in Zsh; but result in a "bad substitution" error in Bash: ${${PWD##*/}//trunk/latest}  or ${$(basename $PWD)//trunk/latest}  the output should be the last folder of the $PWD, replaced by latest when my current directory is trunk so /home/user/trunk should become latest Is there a Bash equivalent allowing to chain expansions without relying on variables or pipes? Or do Bash expansions only allows the input to be a string or a plain variable?


I have a problem with my Ubuntu, I installed tomcat server and set it up, but I needed to change one directory and grant my current user read permissions over it so I executed:  chmod -R 644 /bin   And from there on I kept getting errors, like if i tried to change directory I would get output that there is no such command, so I tried to reopen it (terminal), now when I try to open terminal again it automatically closes, can anyone explain why is this happening and is there a way to reverse it ?

I accidently ran  sudo chmod 755 -R /   instead of  sudo chmod 755 -R ./   I stopped it after few seconds, but now there is some problems such as  sudo: must be setuid root   How can I revert permissions back?


When I planned to fry a chicken, I forgot to get it out of the freezer earlier. I tried to fry it on low heat, so that it can defreeze slowly. Not only is this method really bad for the meat quality, the real issue was that the frozen chicken released its water into the hot oil. I think you all can imagine this mess.  So do you have any suggestion how to defreeze it fast or what else I can do in such a situation if I am in a hurry to fry frozen meat?    Update:  I have already read through the suggested link in the comments, but that does not solve my problem unfortenately. I don't own a microwave and running it under warm water seems to take forever.

What is the safest, quick way to defrost chicken? Microwave? Running water over it?


i was wondering one thing.  Actually .com and all generic domain extensions specifies that the site is available for all countries while country side domain extensions like .fm .mx or .sh specifies to search engines that your site is developed for that specific country,  What if i buy 2 domains like thisismysite.org and site.am and then i  redirect thisismysite.org to site.am , will site.am be treated like a a general domain extension then?  OR i'll need anyway a generic domain to say to search engines that my site is generic all country sides available?

Lets say I have a domain already, for example www.automobile4u.com (not mine), with a website fully running and all.  The title of my "Website" says:    <title>Used cars - buy and sell your used cars here</title>   Also, lets say I have fully SEO the website so when people searching for the term buy used cars, I end up on the second or first page.  Now, I want to end up higher, so I go to the google adwords page where you can check how many searches are made on specific terms.  Lets say the term "used cars" has 20 million searches each month.  Here comes the question, could I just go and buy that domain with the search terms adress, in this case www.usedcars.com and make a redirect to my original page, and this way when people search for "used cars", my newly bought domain name comes up redirecting people to my original website (www.automobile4u.com)?  The reason I believe this benefits me is because it seems search engines first of all check website adresses matching the search, so the query "used cars" would automatically bring www.usedcars.com to the first result right?  What are the downsides for this?  I already know about google spiders not liking redirects, but there are many methods of redirecting...  Is this a good idea generally?


Prove by induction that: $$n^n > (n+1)^{n-1}$$  My atempt so far (I don't know if I'm following the right path): Base case is trivial: $1^1 \geq 2^0 = 1$ For $p(n) \Rightarrow p(n+1)$: $$(n+1)^n> n^n > (n+1)^{n-1}$$ $$(n+1)^{n+1} > (n+1)^n$$ I'm stuck with this and can't figure out how to get the right side to be $(n+2)^n$.

How would one prove that  $$(n+1)^{n-1}<n^n \ \forall n>1$$  I have tried several methods such as induction.


I have linked a Gravatar account to my Stack Overflow account (I don't remember doing it, but it is linked), and the Gravatar account that is linked is not the one I am using. I don't even remember which is the account that is linked. And I don't know its credentials as well.  How can I link another Gravatar account to my profile? I didn't see any option for that anywhere.

Where does the image come from? How do I change my profile picture, or avatar? How do I change my profile picture on all SE sites at once? How can I use different avatars on different SE sites? How do avatars work? How do the SE sites know when I changed my Gravatar? Why do SE sites show a different Gravatar identicon than other sites where I use the same email address? How can I use a Gravatar image after logging in to facebook.stackoverflow.com? I changed my picture but am still seeing the old one    See also:


I'm asking for help installing Ubuntu 64bits on a HP Pavillion 15 through USB.   Disabled Fast-boot Disabled Secure Boot Prioritized USB boot   So I boot into GRUB I select either run or install and I get a black screen. If I select Try Ubuntu I have the Ubuntu loading screen then I get a black screen.  I've tried to Enable Legacy support and prioritize USB (something about if legacy is enabled UEFI is still prioritized) and I still have no luck.

I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:


So I wanted to ask how I get this line/div to the bottom of the header, I am very new to this. I practically only know the basics of HTML and CSS. Answers would be appreciated. (All code can be seen in the screenshot) this is the HTML.

             ABOUT

             VIDEOS

Say I have the following CSS and HTML code:    #header {   height: 150px; }

Header title
   Header content (one or multiple lines)
     The header section is fixed height, but the header content may change.  I would like the content of the header to be vertically aligned to the bottom of the header section, so the last line of text "sticks" to the bottom of the header section.  So if there is only one line of text, it would be like:   ----------------------------- | Header title | | | | header content (resulting in one line) -----------------------------   And if there were three lines:   ----------------------------- | Header title | | header content (which is so | much stuff that it perfectly | spans over three lines) -----------------------------   How can this be done in CSS?


I am well aware of how the Favorite button on the questions works and where I go to find my or anyone else's favorite questions.  I am also well aware of the fact that adding a question to the favorites improves its "hotness score" (and who does not want to show his answers on the main page), since it is public reputation of the question. Correct me if I am wrong.  Adding 1 and 1 made me look into the profiles of some highly-ranked users (on various sites) and the amount of the favorite questions closely matched the amount of their answers. The OP can do probably the same for his questions, but highly-ranked askers are not so common.  Yes. I know that hot questions are not substitute for a good questions and good answers, but the visibility helps.  Everyone have limited amount of votes per day, which affects questions all around, but are the Favorites limited in any way? Is this considered as ethical or is it advisable?

I really like the , where certain questions from the Stack Exchange Network are presented, along with a hotness rating that is described as "arbitrary" in its tooltip. Such questions also appear randomly on the sidebar on sites across the network, under the heading "Hot Network Questions". How do these arbitrary hotness points work, and how are they used to select questions to appear in those lists?


E: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 3476 (aptd) N: Be aware that removing the lock file is not a solution and may break your system. E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?

I'm trying to run this command in the terminal:  sudo apt install software-properties-common   This is the error message I get:  E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable)   E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend),     is another process using it?


I am logged to remote server via ssh (linux) or via putty(windows). I want to copy file back to my origin machine from remote bash prompt (because of convenience). I know I can launch FileZilla or WinSCP at my machine and copy files, but I would like to know how to do that from remote bash prompt.  I know I can copy files via pscp using another ssh link:  pscp server.file localuser@local:/local_path   But this is impossible to use if client does not run a openssh server.  I see that my server has some variables like SSH_CLIENT, SSH_CONNECTION etc. Is it possible to use this information to craft a command like this?  copy_from_server server.file local.file   Where server.file is file located on the server (local to bash prompt where copy_from_server runs) and local.file is destination on client machine where file should be copied.  I would like a solution that works for windows and linux but I am also open to solutions that work on linux only or on windows only.  EDIT: Similar questions:

I use the command "Open in PuTTY" in WinSCP. A PuTTY window pops up, but I cannot find a way to scp files from Linux back to Windows using terminal command line in PuTTY. Do you guys think this is possible?


I wold like to get into the design industry and would like to work my way up to a creative director role. I have also considered art director.   What entry level jobs would you recommend to get there and what career path should follow? I am am keen to work in a team, perhaps with brand management and advertising over different types of media.

I am interested in becoming a creative director, but I have learned that it is not a job you can simply get straight out of college.   Is it possible to become an art director and make your way up to creative director over time? If so, this is the route I'd like to take.


Now, I have a laptop with Windows 8. For various reasons, I want to install Ubuntu that I can carry with me on the various PCs I work with. The same installation so that I don't have to constantly take care of installing new things and dependencies.   Can I do a full installation of Ubuntu in a USB? Can I install softwares and other things in the USB itself so that I can boot it anywhere I want? What is the difference of this installation from full installation on a laptop harddisk? What features will and will not work with the USB option?   Thanks!

I am currently running Ubuntu as a guest vm on a Win 7 host via VirtualBox, but I would like to have a portable version of Ubuntu when I am not using my laptop.   I am unsure as to the difference between the following:  1)LiveCD with persistence; 2)LiveCD without persistence; 3)LiveUSB with persistence; 4)LiveUSB without persistence; 5)Full-install.   I have a USB flash drive (32GB), and I also have empty DVDs lying around. I know that persistence means that data can be saved, but I am unsure as to which option to choose. What is the difference between a LiveUSB and a full-install on a USB thumbdrive and why would I want to pick one over the other? Thanks for any help.


Every bounded sequence has at least one limit point. (Bolzano Weierstrass Theorem) If such a sequence has a unique limit point, need that point be the limit of the sequence?

I'm not entirely sure how to go about proving this so hopefully someone can point me in the right direction. The definition I have for a limit point is "$a$ will be a limit point if for a sequence $x_n$ there exists a subsequence $(x_{n_k})$ such that $\lim_{k\to\infty} (x_{n_k})=a$".   In the forward direction if $x_n$ converges to a value $a$ then every convergent subsequence of $x_n$ must also converge to $a$. I'm not entirely sure where else to go from here. Intuitively I know that what I'm trying to prove must be true since if $x_n$ converges to $x$ then there exists an $N\in\mathbb{N}$ such that $\forall n\geq N$ we have infinitely many terms satisfying $\forall \varepsilon >0\Rightarrow x-\varepsilon<x_n$ which implies that $x$ is a limit point. I'm not entirely sure how to rule out a second limit point. Would it be sufficient to show that if $a$ and $b$ are limits of a convergent sequence $x_n$ then $a$ must equal $b$?  In the backwards direction if $x_n$ is bounded and has only one limit point then we know that there exists only one point $x$ such that we can find infinitely many terms satisfying $\forall \varepsilon >0$ $\left | x_n-x\right |<\varepsilon$ which implies that $x_n$ converges to $x$.   I'm quite concerned I am proving this incorrectly since I don't think I am using any facts about subsequences although they are mentioned directly in the definition for a limit point.


Hi guys i want to call a function from LRESULT CALLBACK but it don't know this function when I call it in LRESULT CALLBACK  LRESULT CALLBACK MYLowLevelKeyBoardProc(int nCode,WPARAM wParam,LPARAM lParam) { qDebug()<<"Key Pressed."; do_eventFilter(); return CallNextHookEx(hHook, nCode, wParam, lParam); }  bool MainWindow::do_eventFilter() { if (!_screenshotPending) {         _screenshotPending=true;         shootScreen();         tt = new MYThread(&scaledPixmap, socket);         QObject::connect(tt, SIGNAL(finished()), this, SLOT(quitThread()));         tt->start();         ui->label_3->setText(QString::number(i++));; } return false; }   It give me this error:   C3861: 'do_eventFilter': identifier not found  It means this method does not known from in this function.

I am creating a keyboard hook, wherein KeyboardProc is a static member of a class CWidget.  class CWidget {    static LRESULT CALLBACK KeyboardProc(int code, WPARAM wParam, LPARAM lParam );  };   I want to call the non-static members of CWidget inside the CWidget::KeyboardProc.   What is the best way to do it?   KeyboardProc does not have any 32 bit DWORD where I can pass the 'this' pointer.


A module I maintain is introducing the ability to customize some messaging that is output to users on the site. Up until now, that messaging has been hard-coded and output using the TranslatableMarkup class. I'm now allowing these strings to be customized in configuration.  Is it still appropriate to just dump whatever the configured string is into the TranslateMarkup class? It seems like I should not do that.  I found this  that seems to be related to what I'm discussing, but there's no clear conclusion on what to do.

The question is fairly straight forward. I have several config entities with various fields.   I haven't found a way to translate config entity fields in the Drupal 8 documentation(or maybe I haven't looked hard enough, both are a strong possibility).


My question is why is there something instead of nothing, and is this indicative of a universal will, not god as such...possibly not even sentient, just a Will to be/exist/create?  Because I may be wrong but existing requires energy (stars/planets/universes/people/big bang) and nothingness requires nothing, so surely it's easier for nothing to exist?  Surely it takes more 'effort' for a star to exist than not, and everything returns to entropy/nothing eventually, if I'm not mistaken...so why bother?

A simple but fundamental question.    The "something" means the whole Universe (known and unknown), it could be represented as the reality version of the set of all sets, which is itself . It includes all the  and such.  A better version of the whole Universe could be described with a .  The "nothing" means an absence of the whole Universe, not a particular void or emptiness in the whole Universe but a nonexistent whole Universe.


In Wikipedia's proof of Riemann's functional equation for the zeta function (, and click "Show Proof"), I find the assertion that $$\sum _{n=-\infty }^{\infty } e^{-n^2 \pi x} = \frac{1}{\sqrt{x}}\sum _{n=-\infty }^{\infty } e^{-\frac{n^2 \pi }{x}}$$ I can't work out how this works. Is it to do with Jacobi theta functions? Mathematica (which seems to use Jacobi's original notation) simplifies the expression on the left hand side above to the Jacobi elliptic theta function (Wikipedia , plus the 'Auxiliary Functions' section that follows) $$ \begin{aligned} \sum _{n=-\infty }^{\infty } e^{-n^2 \pi x} &= \vartheta_{3}(0,e^{-\pi  x}) \\&= \vartheta_{00}(0,e^{-\pi  x}) \\&= \vartheta(0,e^{-\pi  x}) \end{aligned} $$ Wikipedia defines $$\vartheta(z;\tau) := \sum _{n=-\infty }^{\infty } e^{\pi i n^2 \tau+2 \pi i n z}$$ But setting $z = 0$ and $\tau = e^{-\pi  x}$ then gives $$\vartheta(0,e^{-\pi  x}) = \sum _{n=-\infty }^{\infty } e^{\pi i n^2 e^{-\pi  x}}$$ which is clearly not equivalent to the original expression. I suspect that this may have something to do with nomes, which Wikipedia mentions but I cannot get my head around. So, my two questions are:  How do I prove the original equivalence? What am I doing wrong in relation to the Jacobi theta function?

We have the relationship $\theta (x) = x^{-\frac{1}{2}} \theta (x^{-1})$  Now I know one uses the Poisson summation formula to prove this. The Poisson summation formula comes from Fourier Transform and series and satisfies, \begin{equation} \sum_{n=-\infty}^{+\infty} f(n) = \sum_{n=-\infty}^{+\infty} \hat f (n) \end{equation}  So do we say $f(n)= \theta(x)$? (where $\theta(x) =  \sum_{-\infty}^\infty e^{-\pi n^2  x}$)  So filling in we have, \begin{equation} \sum_{n= - \infty}^{+\infty} e^{-\pi n^2  x}= \sum_{m= - \infty}^{+\infty} \int_{- \infty}^{\infty} e^{-\pi y^{2}x}e^{-2 \pi i y m} dy \end{equation}  Now what is the best way to keep going? Do I rearrange with the goal of getting a Gaussian integral (and hence the relationship)? Or is there a more elegant way of achieving the desired result?  What I've done so far is, after completing the square in the power of the integrand, we have \begin{equation} =\sum_{m=-\infty}^{+\infty}\int_{-\infty}^{+\infty}e^{-\pi x((y+i\frac{m}{x})^{2}-i^{2} \frac{m^{2}}{x^{2}})}dy \end{equation}  Then separating the integrand, breaking it up into a product of exponentials again we have,  \begin{equation} =\sum_{m=-\infty}^{+\infty}\int_{-\infty}^{+\infty}e^{-\pi m^{2} \frac{1}{x}} e^{-\pi x (y+i \frac{m}{x})^{2}}dy \end{equation}  The left factor of the integrand is a constant as it does not contain $y$, so it can be brought outside of the integral.  $$ \sum_{n = -\infty}^{+\infty}  e^{-\pi n^{2} x} = \sum_{m=-\infty}^{+\infty}e^{- \pi m^{2} \frac{1}{x}} \int_{- \infty}^{+ \infty} e^{ -\pi x (y+i \frac{m}{x})^{2}} dy $$  What would be the correct approach from here? Should I make a substitution? Any help or suggestions will be appreciated!


I'm experimenting with CUDA Dynamic Parallelism and I have a problem in assuring proper work of parallel Kernel lunches. I've made simple test code:  __global__ void child(int id) {     if(id%10000 == 0)         printf("hello\n"); }  __global__ void parent(int nop) {     unsigned int indX = blockIdx.x*blockDim.x + threadIdx.x;     unsigned int indY = blockIdx.y*blockDim.y + threadIdx.y;     unsigned int ind = indX* ((int)sqrtf(nop) + 1) + indY;     if (ind < nop)     {         if (ind % 10000 == 0) {             child << <1, 1 >> > (ind);             printf("world!");         }     } }   Where nop is a value larger than 1 000 000. I want to pass variable created in parent Kernel to child one but every time I'm getting unspecified failures or BSOD during call. Slowly I'm running out of ideas how to do this properly.  I couldn't find any useful examples for such case.

I've noticed that CUDA applications tend to have a rough maximum run-time of 5-15 seconds before they will fail and exit out.  I realize it's ideal to not have CUDA application run that long but assuming that it is the correct choice to use CUDA and due to the amount of sequential work per thread it must run that long, is there any way to extend this amount of time or to get around it?


I have an SSD mounted in an external enclosure and it was installed as a Windows to Go workstation. The external enclosure has a VL716 chipset and the connection to the PC is done via an USB Type-C cable from the enclosure to USB 3.0 type A.  Windows however shows the following picture (disregard the Iomega drive, that has an HDD inside):    So it's not recognizing the drive as an SSD, the correct picture would be like this:    That was when the SSD was mounted directly to a SATA port of the machine. Wondering if it had something to do with the enclosure I changed it to another USB 3.0 one that uses a different chipset, this time is a JMicron one; but to no avail.  Interestingly, TRIM commands do make it to the disk with both enclosures when issued via PowerShell for example:  Optimize-Volume -DriveLetter D -ReTrim -Verbose   But since Windows doesn't identify it as an SSD I fear it'll try to defragment the drive instead of just issuing a TRIM. I could disable the weekly or daily optimization of Windows and set up an scheduled task to issue TRIM manually but I would rather know what Windows does or how it recognizes SSDs, maybe there's a bug that needs to be reported or I'm missing a step but the Windows to Go installation was performed officially (i.e. not using third party tools) and directly into the SSD, it wasn't cloned.  I apologize for the long read, but I wanted to give you as much details as possible, and if something is missing just let me know to amend the question.

I've brought an SSD and external closure that supports UASP and USB 3.0.  The drive is recognized and the speed is ok. But the drive is recognized as normal hard drive by Windows (8.1). I.e. when I try to optimize the SSD volume it begins to defragment it instead of issuing TRIM command.  My question is what characteristics should an external hdd closure have to have to allow Windows to recognize it as real SSD drive? Is it possible at all with USB 3.0 interface or I need an eSATA interface?


Today,I want to make the sections Append A,B,C in the table of content.However,I don't know how to do.  \documentclass[a4paper,cs4size,UTF8]{ctexart}                         \usepackage{amsmath}                  \usepackage{mathtools} \usepackage{amssymb}              \usepackage{times}                   \usepackage{fancyhdr}                \usepackage[colorlinks,linkcolor=blue,anchorcolor=blue,citecolor=red,unicode]{hyperref}                    \usepackage{lastpage}                 \usepackage{pdfpages}  \pagestyle{fancy}                       \setlength{\headheight}{14.5pt}         \fancyhf{}                             \fancyhead[c]{常州大学本科生毕业论文}              \fancyfoot[c]{第 \thepage 页,共\pageref*{LastPage}页}   \begin{document}  \begin{titlepage}                             \tableofcontents                        \end{titlepage}   \section{Introduction}  \subsection{引言}  babababababababbabababbabababbabababababbbaababbabababab \newpage \section*{Append A} \newpage \section*{Append B} \newpage \section*{Append C} \end{document}

How do I rid of number of a section in the way that it still would be in the table of contents.  If I use   ... \section{SN1} ...   then I see this section name in table of contents as   1 SN1  2 SN2  3 SN3  ...   If I use   \section*{SN}   I don't see it in the content:   1 SN2  2 SN3   How to get in content just   SN1  1 SN2  2 SN3   ?


I need to redirect my webpage in the likes of  /dir/script.php?a=123&b=foobar   to  /123/foobar   I've found many answers for questions like this in this site, but none of them work for my problem. The solution from  answer is almost what I need. It works fine for three parameters:  RewriteRule ^([^/]+)/([^/]+)/([^/]+)$ /letters.php?q=$1&d=$2&t=$3 [NC]   But if I try to rewrite it for two parameters, as need in my case:  RewriteRule ^([^/]+)/([^/]+)$ /dir/script.php?a=$1&b=$2 [NC]   I get a 500 Internal Server Error. My script is not even executed. I have tested the regex in Perl and it works fine. There is nothing wrong with it, but Apache somehow refuses to accept it.  I am using the following Apache version:  Server version: Apache/2.4.10 (Debian) Server built:   Nov 28 2015 14:05:48   Can someone help me get this working?  EDIT:  I can't see how this is a duplicate question. The referred question has no mention whatsoever of a dynamic directory based redirection. It mentions named directory redirection, but that is completely different from what I am trying to achieve.  As requested, the log from Apache shows the following:     AH00124: Request exceeded the limit of 10 internal redirects due to   probable configuration error. Use 'LimitInternalRecursion' to increase   the limit if necessary. Use 'LogLevel debug' to get a backtrace.   EDIT2:  It was actually re-matching the /dir/script.php and redirecting indefinitely. The solution was to add the flag END to the RewriteRule, as specified in the :     An alternative flag, [END], can be used to terminate not only the   current round of rewrite processing but prevent any subsequent rewrite   processing from occurring in per-directory (htaccess) context. This   does not apply to new requests resulting from external redirects.

This is a  about Apache's mod_rewrite.   Changing a request URL or redirecting users to a different URL than the one they originally requested is done using mod_rewrite. This includes such things as:   Changing HTTP to HTTPS (or the other way around) Changing a request to a page which no longer exist to a new replacement. Modifying a URL format (such as ?id=3433 to /id/3433 ) Presenting a different page based on the browser, based on the referrer, based on anything possible under the moon and sun. Anything you want to mess around with URL   Everything You Ever Wanted to Know about Mod_Rewrite Rules but Were Afraid to Ask!  How can I become an expert at writing mod_rewrite rules?   What is the fundamental format and structure of mod_rewrite rules? What form/flavor of regular expressions do I need to have a solid grasp of? What are the most common mistakes/pitfalls when writing rewrite rules? What is a good method for testing and verifying mod_rewrite rules? Are there SEO or performance implications of mod_rewrite rules I should be aware of? Are there common situations where mod_rewrite might seem like the right tool for the job but isn't? What are some common examples?   A place to test your rules  The  web site is a great place to play around with your rules and test them. It even shows the debug output so you can see what matched and what did not.


I am shooting my first wedding in September and I have a Canon rebel t3i with a 50 mm 1.8 and I am trying to find a good lens under $900 dollars for the wedding so I am not stuck with just one lens. Any suggestions on what lens I should get next? I had looked into the 17-55mm 2.8? Is that any good?

I am new to photography. I have Canon 1000d (with 18 -55 mm lens). My basic interest is wedding photography.  I am planning to get a prime and a telephoto lens. So, my dilemma is:   Should I go for 50mm f/1.8 or 50 mm f/1.4 or 85mm f/1.8 For a telephoto zoom... should I consider 55-250mm IS??   kindly suggest.  ps: Please note that I am mainly interested in shooting weddings....


Definitions of positive definiteness usually look like this:     A symmetric matrix $M$ is positive definite if $x^T M x > 0$ for all vectors $x \neq 0$.   Why must $M$ be symmetric? The definition seems to make sense for general square matrices.

Do positive semidefinite matrices have to be symmetric? Can you have a non-symmetric matrix that is positive definite? I can't seem to figure out why you wouldn't be able to have such a matrix, but all my notes specify positive definite matrices as "symmetric $n \times n$ matrices."  Can anyone help me with an example of a non-symmetric positive definite matrix, or some insight into a proof for why it would need to be symmetric should that be the case? Thanks!


Occasionally this happens on chrome from a mac:    Single line code markdowns can thereafter be difficult to read. Clicking elsewhere on the page doesn't seem to 'undo' this. My workaround is to double click the code and paste it into the address bar where it's easily read. Is there a better way around this?   Or could either the scroll bar height be reduced or the height of the markdown box be increased?   Note: example

This question is a duplicate of  (but this question can't be marked as a duplicate because that question is on meta.stackoverflow.com, and this question is on meta.stackexchange.com).  I'm seeing a bug on stackoverflow.com. I'm not sure if the culprit is Stack Overflow, Google Chrome, or macOS.  (Below I refer to a "code box". By that I mean some text that begins with 4 spaces when editing a question or answer.)  When I hover over a code box that contains one long line of code, a horizontal scrollbar appears. When I stop hovering over the code box, very frequently (maybe 3 out of 4 times) the scrollbar does not disappear. Clicking elsewhere on the page also does not dismiss the scrollbar. The only way to dismiss it is to refresh the page.  ...After experimenting more, it appears to always happen if I enter the box from below, but not always when I enter from above. It seems to be triggered by hovering over the lower half of the box.  Also if I enter from the top and scroll to the right, then until I refresh the page again that scrollbox will behave normally (only show a scrollbar when scrolling, and disappear after). In that case the scrollbar also has a different appearance, being much less tall (maybe a quarter of the height of the code box rather than half as tall).  Further, if I get a box and scrollbar into that functional state and then hover over the lower part of the box for a bit, then sometimes eventually it will break and stay broken until refresh again.  And in any case hovering over the lower part of the box causes the scrollbar to get taller.  Here is a screenshot of the issue:        Google Chrome 71.0.3578.98 (Official Build) (64-bit)  macOS High Sierra 10.13.6  Here is a code box that repros the issue for me:  fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo   Here is another:  foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo foo


In my PC, there is 8GB RAM and runs Windows 10 64-bit OS. In the task manager, I can see that the OS is utilising 50%, that is, approximately 4GB of RAM and the remaining 4GB is free. But, in my friends' computers, which have 4GB RAM, there also I saw that the OS is utilising 50% of RAM. In many computers, there are just 2GB RAM, but it runs fine and there also only 50% memory usage.  So, I am wondering, how does the OS adjusts itself to the available RAM space?

I was thinking to add some RAM to my computer as it goes slow these days, so i came to the Taskbar to see memory usage statistics but i had difficulty  guessing the real meaning of some memory management parameters. so  Q1: What exactly are Commited Memory, Cached, Paged , Not-Paged pool and how they are different with In-Use Memory.  Q2: As far as i know the kernel has a complex memory management algorithm, so if i have some free memory shown in my laptop's RAM can i conclude that my physical memory is sufficient?


What is the difference between "ls –alR /" and "ls –alR / &"? I seem to get the same out put. but the & sign i think should run it in background?

The program Boblight does not run in background. There is no noticeable difference between executing   sudo boblightd   and   sudo boblightd&    How can I solve this problem that the console will not block further inputs?  pi@raspberrypi ~/boblight/boblightd-for-raspberry-master $ sudo boblightd Boblightd 2.0 (optimized version for raspberry) (c) 2013 Speedy1985 and Heven) (InitLog)                       start of log /root/.boblight/boblightd.log (PrintFlags)                    starting boblightd (CConfig::LoadConfigFromFile)   opening /etc/boblight.conf (CConfig::CheckConfig)          checking config lines (CConfig::CheckConfig)          config lines valid (CConfig::BuildConfig)          building config (CConfig::BuildConfig)          built config successfully (main)                          starting devices (CClientsHandler::Process)      opening listening TcpSocket on *:19333 (CDevice::Process)              ambilight: starting with output "/dev/spidev0.0" (CDevice::Process)              ambilight: setting up (CDevice::Process)              ambilight: setup succeeded   pi@raspberrypi ~/boblight/boblightd-for-raspberry-master $ sudo boblightd& [1] 2289 pi@raspberrypi ~/boblight/boblightd-for-raspberry-master $ Boblightd 2.0 (optimized version for raspberry) (c) 2013 Speedy1985 and Heven) (InitLog)                       start of log /root/.boblight/boblightd.log (PrintFlags)                    starting boblightd (CConfig::LoadConfigFromFile)   opening /etc/boblight.conf (CConfig::CheckConfig)          checking config lines (CConfig::CheckConfig)          config lines valid (CConfig::BuildConfig)          building config (CConfig::BuildConfig)          built config successfully (main)                          starting devices (CClientsHandler::Process)      opening listening TcpSocket on *:19333 (CDevice::Process)              ambilight: starting with output "/dev/spidev0.0" (CDevice::Process)              ambilight: setting up (CDevice::Process)              ambilight: setup succeeded


I want to show that $\text {rank} ( AB)\le \min(\text{rank} B, \text{rank} A) $ and when the equality occurs? Please help me with this problem by giving hints, solving, or suggesting a book. Thanks

How to prove $\text{Rank}(AB)\leq \min(\text{Rank}(A), \text{Rank}(B))$?


I recently moved all my music to a separate partion, moved ~/Music to ~/Music-bak and symlinked a new Music directory to the partition.   Nautilus updated the bookmarks to show "Music-Bak" under Computer. How do I tell it that "Music" is my real music folder?

In previous releases of Ubuntu, I used Ubuntu Tweak to change the paths to the user folders (Music, Documents, Videos, etc). I can't find an option in Gnome 3 to do this, and Ubuntu Tweak's ppa still has no version for Oneiric.


I'm new to LaTeX and am using the Harvard-style template on overleaf.  Following is my file:   \usepackage[english]{babel} \usepackage[utf8]{inputenc} \usepackage{amsmath} \usepackage{csquotes}  \usepackage{geometry} \geometry{a4paper,scale=0.8} \usepackage{graphicx} \usepackage[style=authoryear-ibid,backend=biber]{biblatex} \let\cite\parencite  \addbibresource{Ref.bib}% Syntax for version >= 1.2  \title{} ... \printbibliography \end{document}   My problem is when I use \cite{{pauling1960, repp2004}}, I got (Pauling 1960; Repp et al. 2004) rather than (Pauling, 1960; Repp et al., 2004). The comma is missing.   What's the problem?

I use the authoryear style in biblatex, and when I do for instance \cite{bauman2000}, I get:       Bauman 2000   But I would like to add a comma between the author and the year, in order to have      Bauman, 2000   Is there a simple command to get this change ?


At first I wanted to make me into a bootable Linux flash LTS 16.04, After the installation process is finished I want to restore my flash as before. when I checked, it turned my flash partitioned for making bootable "startup disk creator".    when I want to delete the partition had made an error.      Error Formatting Volume: This partition cannot be modified because it contains a partition table; please reinitialize layout of the whole   device. (udisks-error-quark, 11)   and when I want to delete partitions also occurred error:  Eror Deleting Volume: Error deleting partition /dev/sdb1: Command-line `parted --script "/dev/sdb" "rm 1"' exited with non-zero exit status 1: Warning: The driver descriptor says the physical block size is 2048 bytes, but Linux says it is 512 bytes. (udisks-error-quark, 0)   What should I do?

I was using:  dd  if=/path/to/my/ubuntuiso/ubuntu.iso  of=/dev/sdb1  bs=4M  &&  sync   In order to create bootable Ubuntu USB drives on older Ubuntu versions. It was working perfectly. Sometimes I used the Startup Disk Creator program, which  worked well.  But when I use the same methods on Ubuntu 16.04 LTS, I get some warnings while formatting it afterwards.   The installation media works as expected, but when I try to format that USB stick after my work is done, I get the following warning :    The partitioning of that Pendrive looks strange :    And it also shows my 16GB pendrive as 64GB.  After struggling a lot with Gparted, I will somehow format it. But Why is it happening like this ?? Is there any better methods of creating bootable Ubuntu in 16.04 ?  EDIT : there is a related question . But my question is not about how to format it properly. My question is "How to create a bootable USB without that errors." & "Wht are the causes of that error"


I noticed my profile picture on the SE sites is displayed as the default Facebook avatar, even though I do have a profile picture on Facebook which used to be displayed on Stack Exchange until yesterday. Examples:       I assume it is a bug either from Facebook or from the profile picture fetching  algorithm.

Facebook changed how their API serves profile pictures that are requested with a non-application scope UID. Now because before Graph API 2 all applications shared the original UID, if users like me has joined Stack Exchange websites before  2, rolling out their profile pictures are not shown properly. Facebook suggests to use an access token to query those profile pictures, either an application access token or a user access token. A user access token is not a reliable option at all, because it would only work for users who joined website with Facebook and are currently logged in. Application access tokens, by the way, can be used by creating sort of a proxy that would retrieve a profile picture from Facebook and display it. Yet still it's not perfect. I think the best solution is to communicate with Facebook and ask them to offer an opportunity to convert old Graph API 1 UID's to application scope user IDs.


I need to do a phone number validation that the tel# contains only: numbers 0-9 left and right parenthesis hyphen blank space  in c#  this is my code for now:  //ValidatePhoneNumber     public static string ValidatePhoneNumber(string v_strPhoneNumber)     {         const string strPHONE_NUMBER_BLANK =            "Phone Number cannot be blank";         const string strPHONE_NUMBER_TOO_LONG =             "Phone Number cannot be longer than 24 characters";          if (v_strPhoneNumber.Trim().Length == 0)             return strPHONE_NUMBER_BLANK;         if (v_strPhoneNumber.Trim().Length > 24)             return trPHONE_NUMBER_TOO_LONG;          return String.Empty;      }//end ValidatePhoneNumber   I need to add that validation into that code, I am a beginer so the easiest way possible would be great. If you can give me the answer please if you could at least point me in the right direction, Thanks!

I'm trying to put together a comprehensive regex to validate phone numbers. Ideally it would handle international formats, but it must handle US formats, including the following:   1-234-567-8901 1-234-567-8901 x1234 1-234-567-8901 ext1234 1 (234) 567-8901 1.234.567.8901 1/234/567/8901 12345678901   I'll answer with my current attempt, but I'm hoping somebody has something better and/or more elegant.


I'm trying to bind two parameters to a prepared PDO select statement. This is what I have so far:  $query = "select * from books where ? LIKE ?"; $result = $db->prepare($query); $result->bindValue(1, $searchTerm, PDO::PARAM_STR); $result->bindValue(2, "%$searchValue%", PDO::PARAM_STR); $result->execute(); $rows = $result->fetchAll(PDO::FETCH_ASSOC); print_r($rows);   This executes successfully but I don't get any rows returned.  But when I use only 1 param  $query = "select * from books where title LIKE ?"; $result->bindValue(1, "%$searchValue%", PDO::PARAM_STR);   I get rows returned. I've checked 1000 times for my param values and names and they are fine.  I don't understand why this doesn't work with two params. Please advice.

Why can't I pass the table name to a prepared PDO statement?  $stmt = $dbh->prepare('SELECT * FROM :table WHERE 1'); if ($stmt->execute(array(':table' => 'users'))) {     var_dump($stmt->fetchAll()); }   Is there another safe way to insert a table name into a SQL query? With safe, I mean that I don't want to do  $sql = "SELECT * FROM $table WHERE 1"


Throughout the Dr. Who series, the doctors have claimed to be hundreds, even thousands of years old, (the tenth and eleventh both claim to be around 900, but throughout the series, eleven jumps into the thousands, even though its only been a few years for his companions, and now the 12th claims to be 2,000) but in relation to what?  He is constantly jumping around through time, making it difficult to track.  Does he claim his age to be in relation to Gallifrey as if he hadn't left or it hadn't been burned, (or saved, it's all too timey-wimey for me to make sense of) or does he simply not know?

I've often wondered, how does the Doctor know how old he is? He not only travels through time, but also through space, and visits planets where days can be shorter or longer than 24 hours. How does he 'keep score'?  Also, does he count his age in Earth years or Gallifrey years? They might be completely different in length.


In past tense when is it better to use one over the other?  has been [verb] vs has [verb]  For example:      Your order has been shipped vs. Your order has shipped     Is there a difference between the two?

I ordered a CD from an online music store. My confirmation email reads "your order has shipped." English is not my first language, and this strikes me as odd. Shouldn't it be a passive-voice sentence, i.e. "your order has been shipped"?


On Page 108 of the book Algebraic Topology, Allen Hatcher, the singular homology of a topological space $X$ is defined to be the homology of the chain complex by setting the $n$-chains $C_n(X)$ as the free abelian group with basis $\text{Map}(\Delta^n,X)$, where $\Delta^n$ is the standard $n$-simplex, and  the boundary map $\partial_n$ as $$ \partial _n (\sigma)=\sum_i (-1)^i\sigma\mid_{[v_0,\cdots,\hat v_i,\cdots,v_n]}, $$  where $\sigma$ is a map from $\Delta^n$ to $X$ and $\sigma\mid $ is the restriction of $\sigma$.    Let $K$ be a simplicial complex and let $|K|$ be the geometric realization of $K$. Suppose the vertices ($0$-simplices) of $K$ are $v_0,v_1,\cdots,v_k$, $k$ finite. Let $$ K_{n}= \text{Simplicial Map}(\Delta^n,K). $$ Then $$ K_n\cong\{f\in \text{Map}(\mathbb{Z}_{n+1},\mathbb{Z}_{k+1})\mid \text{ there exists a simplex } \sigma\in K \text{such that Im}f \text{ is the set of vertices of } \sigma\}.  $$ Here we use $\mathbb{Z}_{n+1}$ to represent the set of all vertices of $\Delta^n$ and use $\mathbb{Z}_{k+1}$ to represent the set of all vertices of $K$. Let $C_n(K)$ be the free abelian group with basis $K_n$. Analogous to the boundary map in singular homology, there is a boundary map $$ \partial_n: C_n(K)\longrightarrow C_{n-1}(K).  $$  Question:  Is the singular homology of $|K|$ same or different with the homology of the chain complex $$ \cdots C_n(K)\overset{\partial_n}{\longrightarrow} C_{n-1}(K)\overset{\partial_{n-1}}{\longrightarrow}\cdots\overset{\partial_1}{\longrightarrow} C_0(K) ? $$

Let $X$ be a simplicial set. Define the complex $(C^X_\bullet,D)$ by  $$C^X_n=\bigoplus_{X_n} \mathbb{Z}$$ and $$D_n=\sum_{i=0}^n (-1)^i d_i:C_n \to C_{n-1}$$ where the $d_i$'s are the face maps.   I wonder if there is a relation between the homology of $(C^X_\bullet,D)$ and the singular homology of $|X|$, the geometric realization of $X$.   I know that there is a weak equivalence $X \to S|X|$ and that the singular homology of $|X|$ is exactly the homology of $(C^{S|X|},D)$ as defined above. But I cannot conclude yet that there is a homotopy equivalence between the complexes $(C^X,D)$ and $(C^{S|X|},D)$, do I ?


Is there any Difference between   if(! (xyz === abc) ) { }   AND  if( xyz  !== abc ) { }   if both are same, which one should we prefer?

CPU Cycles, Memory Usage, Execution Time, etc.?  Added: Is there a quantitative way of testing performance in JavaScript besides just perception of how fast the code runs?


Not sure if this is the right place to ask, but all well, I will ask anyway...    I am hard-pressed with finding an online course that teaches General Relativity in full. I would like to learn General Relativity but I cannot seem to find anything on Google. Is there an online course or courses (free or paid, it doesn't matter to me) that someone can recommend or show me? Maybe it's a University that offers it, and I would be fine with that.  Note: I am a beginner to General Relativity.

What are some good books for learning general relativity?


my google account and password is correct but it keeps saying you entered the wrong password or your account has changed. it still has me logged in on the email but this error sign will not go away.

I do not have Google+, I do not have 2 step verification, and I have no data to show in my data tools tab online.  So, why do I keep getting an error message that my password is incorrect or my account has changed?  I didn't change anything, in fact, I never use it.  Have I been hacked?  If so, how can I resolve this so it doesn't keep happening?


I can't delete all the undefined indexes in this array.I do console.log and it shows me [undefined, 2].  var array = []; array[1] = 2; array[3] = 4;  for(var i = 0; i < array.length; i ++) {   if(array[i]) {    } else {     array.splice(array.indexOf(array[i]), 1);   } }  console.log(array)

How do I remove empty elements from an array in JavaScript?   Is there a straightforward way, or do I need to loop through it and remove them manually?


I really hate spiders and I'm afraid of them so this is really a problem for me. I use bike every day to get everywhere - to work, to shop etc. These nasty things can make a web in a matter of a few hours here (Cambridge, UK) - almost every morning when I want to get to work there is a web, almost every afternoon when I want to go home there is a web. Sometimes there is even a spider. It's really annoying and terrifying. I found this:  but it wasn't really helpful. I was thinking about spraying my bike with Raid or something, or maybe spraying it with some kind of water solution with washing liquid and essential oils (I read that some of them repel spiders). Do you have any advice on this? Or maybe at least some advice on dangerous fluids for my bike that I shouldn't use for this? (Like water makes my bike rusty)

What kind of maintenance should I do before putting my bike into storage for the winter?  Are there any special considerations for storing it?  Does temperature matter?  If it's hanging on the wall from the rim all winter long, will that affect the shape of my rims?  Any other winter storage advice would be nice to hear.


I'm trying to download a module from CPAN and save it into the same directory as the directory that my Perl script is in because I don't have permissions to download it normally, but when I try to run the code, it can't find the script.  My Code:  #usr/bin/perl use Spreadsheet::WriteExcel;   Error Message:  Can't locate Spreadsheet/WriteExcel.pm in @INC at temp.pl line 3. BEGIN failed--compilation aborted at temp.pl line 3.   How can I tell Perl where to look for the module? Thanks.

I have a module in the parent directory of my script and I would like to 'use' it.  If I do  use '../Foo.pm';   I get syntax errors.  I tried to do:  push @INC, '..'; use EPMS;   and .. apparently doesn't show up in @INC  I'm going crazy!  What's wrong here?


Let $n$ and $1\leq k \leq n$ be natural numbers. Prove the inequality     $$\sum_{i=k}^n \binom{n}{i}\bigg(\frac{k}{n+1}\bigg)^i\bigg(1-\frac{k}{n+1}\bigg)^{n-i} \leq 1 - \frac{1}{e} $$  Equivalently, if $X\sim$ Bin($n$,$\frac{k}{n+1}$), prove that $\mathbb{P}[X\geq k] \leq 1 - \frac{1}{e}$.   My attempt: It may be helpful to show that the LHS tends to a limit less than $1-\frac{1}{e}$ as $n \to \infty$ (already did that) and that the LHS is an increasing function on $n$ (have not done that).

Let $n$ and $1\leq k \leq n$ be natural numbers. Prove the inequality     $$\sum_{i=k}^n \binom{n}{i}\bigg(\frac{k}{n+1}\bigg)^i\bigg(1-\frac{k}{n+1}\bigg)^{n-i} \leq 1 - \frac{1}{e} $$  Equivalently, if $X\sim$ Bin($n$,$\frac{k}{n+1}$), prove that $\mathbb{P}[X\geq k] \leq 1 - \frac{1}{e}$.   My attempt: It may be helpful to show that the LHS tends to $1-\frac{1}{e}$ as $n \to \infty$ (already did that) and that the LHS is an increasing function on $n$ (have not done that).


var a = 10  function fun(){      var b = 20  } fun()   In this code var a has global scope but var b dont have global scope but functional scope. But as fun() itself is global function which will be global to everywhere why var b is not global

What is the scope of variables in javascript? Do they have the same scope inside as opposed to outside a function? Or does it even matter? Also, where are the variables stored if they are defined globally?


I am a Linux user since 2010. I used Debian, elementary OS (which is also Ubuntu) and now I'm using a fresh install of Ubuntu itself.  But I'm already having some problems that I can't find how to solve. The first of them is that there are some missing settings on my configurations. See:    I can't see the wallpaper settings, screensaver or date and time settings. I can set wallpaper by right-clicking an image and then clicking on "Set as wallpaper". No way to set screensaver. I can set the date from the terminal, but I can't show to my personal friends how amazing Linux is and encourage them to change to it, if even to set the clock they must see me going to terminal. If I click the date and then click 'Date and time settings', it just shows up the configurations panel (from image above). Also, I work with different timezones, and I want to see many timezones when I click the date in topbar, which is not being possible.  I couldn't find another topic with exactly the same problem...

I did a fresh install of trusty 14.04, but a lot of icons are missing. I installed from DVD which was painfully slow and I hope to avoid repeating the process, especially since I started customizing stuff.  Here's my settings window:    I've tried:  sudo apt-get install --reinstall gnome-control-center sudo apt-get install --reinstall gnome-settings-daemon-schemas   None of which changed anything.  Any idea? I wanna edit preferences and none of them are in System Settings, neither in Unity Dash.


I'm trying to parse the xml-response from the amazon api.  This is a part of the received xml-file:  <BrowseNodeLookupResponse xmlns="http://webservices.amazon.com/AWSECommerceService/2011-08-01">   <OperationRequest>     <RequestId>31317fca-ad3d-4ff0-a64f-693c0e44959b</RequestId>     <Arguments>       <Argument Name="Operation" Value="BrowseNodeLookup" />       <Argument Name="Service" Value="AWSECommerceService" />       <Argument Name="Version" Value="2011-08-01" />       <Argument Name="BrowseNodeId" Value="186606" />       <Argument Name="Timestamp" Value="2015-01-04T11:50:06Z" />       <Argument Name="ResponseGroup" Value="BrowseNodeInfo" />     </Arguments>     <RequestProcessingTime>0.002221</RequestProcessingTime>   </OperationRequest>   <BrowseNodes>   I want to read the Argument Timestamp. This is my code, but it only work if I remove the xmlns attribute in the xml-file.       Dim nodeTimestamp As XmlNode = doc.SelectSingleNode("/BrowseNodeLookupResponse/OperationRequest/Arguments/Argument[@Name='Timestamp']")      Dim text As String = nodeTimestamp.Attributes.ItemOf("Value").InnerText

I've got an XML document with a default namespace. I'm using a XPathNavigator to select a set of nodes using Xpath as follows:     XmlElement myXML = ...;   XPathNavigator navigator = myXML.CreateNavigator(); XPathNodeIterator result = navigator.Select("/outerelement/innerelement");   I am not getting any results back: I'm assuming this is because I am not specifying the namespace. How can I include the namespace in my select?


There is a creepy user who answered my question on Stack Overflow that I haven't accepted the answer with. He then keeps leaving a comment for like three consecutive days, asking for updates on his answer (which I interpret as basically asking me to accept his answer already). He also edits my old questions several times which I assume he is doing to get my attention. Well, he did.  My reputation count has been silent over the years with only occasional upvotes from old questions. Now ever since this creepy user started nagging me, my old questions suddenly gets a downvote once a day straight for a whole week now.  The thing is I've been here On Stack Overflow for 8+ years, and I've never encountered this. My silent reputation count suddenly getting downvotes along side with him nagging me makes me suspicious that it's probably his doing.  I understand that similar downvote attacks has been reported and systems are in place to detect this, but I think this creepy user could be deliberately doing it once a day at different times as to not trigger any alarms or he may even be using dummy accounts. Is there a way we can manually check on this?

I recently noticed (and ) a pattern of systematic downvoting by one user against all my questions and answers.  I have honestly no idea what the user's reasons or motivations are, since we have not interacted at all, barely even crossed path on the site (both answered the same question once), but he is clearly targeting me, not my content (which there is no physical way he could have read entirely during his downvoting sprees). He has not left a single comment on any post to justify his downvotes, nor has he replied to my polite requests to explain himself and/or stop this.  His first wave of downvotes was automatically reversed by the system yesterday, and I would have left it at that... But he has been at it again today, and just seems to have no other activity than downvoting my every contributions, which is getting a bit old, to be honest. This really isn't about the reputation points (which get returned each time by the system anyway), but I think a verbal notice enjoining him to play nicer with the community could go some way...  Because this particular form of abuse only has to do with votes, not post content, I don't think there is any way to flag him within the site (?). Also, because  is still pretty young, it appears we do not have any moderators yet (pro tempore or otherwise)... Would any meta-SO moderators mind taking a look at it?  Edit: somehow missed  when posting mine. Though I do not know what the policy for redundancy is, with support-requests... Please if necessary, feel free to close this question and I'll happily repost over there.


I am using Oracle VirtualBox oftet, which conflicts with Hyper-V feature of Windows, which I don't use. So, I am turning Hyper-V off.  Nevertheless, from time to time, probably during major upgrades, Windows set it back on again.  How to prohibit this setting forever? May be delete some files or lock subdirectories? Any solution for robot disobey 1st law of robotics appreciated.  UPDATE  The question was not how to disable Hyper-V as in "duplicated" ones. The question was how to disable it FOREVER.  For example, this method    provides only temporary disabling, which will restore on next windows update.

I really like the Hyper-V support in Windows 8, however, there are some situations in which I need to disable Hyper-V in order to run some apps which don't like to be executed even in the root partition of the virtualized environment. What I've been currently doing is disabling the feature completely from the "Add or remove windows features" dialog and restarting, enabling it again when needed. I would like to know if there's any better way to do this that comes to mind, it could even be a shortcut that i could double-click and will actually add or remove the feature for me and restart (I guess this may be possible with a PowerShell script).


Is it possible to install Ubuntu in a USB device? Don't want a live version, I want to install it like it was in a partition, install programs and save files. If so, how can I do it? I haven't found anything that makes me feel comfortable. Thank you guys!

If you are hurrying to reply, System → Administration → StartUp Disk Creator -- no, that's not what I'm talking about.   I want to try Ubuntu 11.04's Unity without touching my existing Ubuntu install.  To do this, I need to install the nVidia drivers first (sigh).  To do this, I need changes to persist a reboot.  To do this, I need to really install Ubuntu on a USB key.  How do you do that?    What I tried   I tried to make a USB key from , then boot from it, then choose "Install Ubuntu." The installer refused to install to the installation media itself. I tried, from my installed copy of Ubuntu:  sudo kvm /dev/sdb --cdrom .cache/testdrive/iso/ubuntu_natty-desktop-i386.iso   ...but the installer didn't detect the disk properly.


We have two different way for doing function expression in JavaScript:  Named function expression (NFE):   var boo = function boo () {   alert(1); };   Anonymous function expression:  var boo = function () {   alert(1); };   And both of them can be called with boo();. I really can't see why/when I should use anonymous functions and when I should use Named Function Expressions. What difference is there between them?

I've recently started maintaining someone else's JavaScript code. I'm fixing bugs, adding features and also trying to tidy up the code and make it more consistent.  The previous developer used two ways of declaring functions and I can't work out if there is a reason behind it or not.  The two ways are:  var functionOne = function() {     // Some code };     function functionTwo() {     // Some code }   What are the reasons for using these two different methods and what are the pros and cons of each? Is there anything that can be done with one method that can't be done with the other?


I just switched to Ubuntu and I'm following the instructions on   I typed this command  sudo apt-get install qemu-kvm libvirt-bin ubuntu-vm-builder bridge-utils ia32-libs-multiarch   and got the following error:  E: Package 'libvirt-bin' has no installation candidate   E: Unable to locate package ubuntu-vm-builder   E: Unable to locate package ia32-libs-multiarch     I looked for the package , but it looks like it's not there for Cosmic distribution.  Is there is a way that I configure VM acceleration equivalent to that explained in the tutorial?     Edit:  has an answer explaining that the package libvirt-bin was split intolibvirt-daemon-system and libvirt-clients, but I need a solution for the other packages ubuntu-vm-builder and ia32-libs-multiarch too.

I'm trying to install KVM\qemu on Ubuntu 18.10.  According to  I'm running the command:  apt-get install qemu-kvm libvirt-bin ubuntu-vm-builder bridge-utils   and get an error about the packge "libvirt-bin" and "ubuntu-vm-builder":  E: Package 'libvirt-bin' has no installation candidate E: Unable to locate package ubuntu-vm-builder   I see that the package "libvirt-bin" is .  The main repository is set. Anything that I'm doing wrong? Couldn't find any info regrading this issue.  Is it the new Ubuntu version (18.10)?  Thanks


I want to make a copy of a list of records.  The code below only copies references of the records so changing Data in myRecs1 also changes it in MyRecs2.  Besides doing a loop in a loop, is there an easy way to get a full copy of myRecs2 from myRecs1?      static void Main(string[] args)     {         List<MyRec> myRecs1 = new List<MyRec>()         {             new MyRec() {Id = 1, Data = "001"},             new MyRec() {Id = 2, Data = "002"},             new MyRec() {Id = 3, Data = "003"}         };          //List<MyRec> myRecs2 = myRecs1.ToList(); // does not work of course          // ugly but works         List<MyRec> myRecs2 = myRecs1.Select(rec => new MyRec()         {             Id = rec.Id,             Data = rec.Data         }).ToList();          myRecs1[2].Data = "xxx";           foreach (var rec in myRecs2)         {             Console.WriteLine(rec.Data);         }     }      public class MyRec     {         public int Id { get; set; }         public string Data { get; set; }     }    edited to show working example I don't like

I want to do something like:  MyObject myObj = GetMyObj(); // Create and fill a new object MyObject newObj = myObj.Clone();   And then make changes to the new object that are not reflected in the original object.  I don't often need this functionality, so when it's been necessary, I've resorted to creating a new object and then copying each property individually, but it always leaves me with the feeling that there is a better or more elegant way of handling the situation.  How can I clone or deep copy an object so that the cloned object can be modified without any changes being reflected in the original object?


Let $V$ be a finite dimensional vector space and let $T:V \to V$ be a linear operator. If the rank of $T^2$ equals then rank of $T$, prove that $(\operatorname{range} T) \cap (\ker T)=\{0\}$  I just want to know whether I'm correct or not. First $T^2$ implies that T is squared, then rank of $T^2=$ rank of $T$ means that $T$ is full rank is that correct? Then the range of $T$ is the space $V$.Is the $\ker T$ means that $\ker T=\{v:T(v)=0\}$? If so range $T \cap \ker T=\{0\}$ right?

Let $V$ be a finite-dimensional vector space and let $T:V\to V$ be linear. Prove that if $\operatorname{rank}(T) = \operatorname{rank}(T^2)$, then $R(T) \cap N(T) = \{0\}$. I don't see this implication, at all. Please give hints and explain conceptually.


How would one extract a number starting with a "£" sign from a cell containing alphanumeric characters?  Example: extracting £450,000 from A1 and placing in B1. See image for example text

I want to extract the numerical value immediately following the string "ABS" (Case sensitive) within a bulk of text in a cell from an Excel table.   Not all the cell may contain the the string I'm looking for, so a filter is required.   The contents of the cell look something like this:     Lorem ipsum dolor sit amet, consectetur adipiscing elit. Morbi ante   mi, laoreet nec tristique et, sodales at dui. Vestibulum ullamcorper   augue at nibh auctor laoreet ornare nisi posuere. Aliquam convallis   nisl auctor mauris pharetra faucibus. Nullam nulla dolor, varius   viverra facilisis nec, viverra in tortor.  Integer sollicitudin, elit   in tempor interdum, sapien justo luctus justo, id varius nisi mauris   at ipsum. Vivamus tincidunt neque sed felis accumsan tempus.      ABS: 1.5, ADS: 2.5, SR: 11      Pellentesque habitant morbi tristique senectus et netus et malesuada   fames ac turpis egestas. Integer vestibulum felis et lorem pretium   molestie. Nulla imperdiet, magna vel accumsan ornare, augue quam   ornare justo, vitae volutpat turpis orci quis nibh. Nullam vitae diam   et ligula commodo pretium. Etiam et luctus dui.   The trouble is since the contents are entered manually, they may vary in structure, with slight variations such as:     ABS : 1.5 (Space after ABS)    or     ABS is 1.5 ('is' instead of colon)   or     ABS = 1.5 ('=' instead of colon)   or      ABS 1.5 (numerical value immediately after text without colon)   ....etc  The numerical value is between 0-8.5 with increments of 0.5, (i.e. 0, 0.5, 1.0, ... 7.5, 8.0, 8.5).  I have tried a combination of left() and find() functions but don't know how to just extract the numbers after finding the string "ABS". If someone can help or point me in a direction, I would greatly appreciate it. Thanks!


Explain their differences if you like...  I wanted to ask when it is appropriate to use the conjunction 'that' in a sentence. For example:   The question I want to ask is...   Or  -The question that I want to ask is...  I can't think of more examples right now. But you get what I'm saying. Why do we sometimes use it and sometimes not use it? When is it correct to use??

Sometimes, the word 'that' to introduce a dependent clause is optional.  For example, these sentences both make sense with or without 'that':  Long books [that] religious people like tend to be Bibles. Water tanks [that] fish need are spacious.  ... whereas in these sentences, 'that' is mandatory and the sentence is ungrammatical without it:  Those that are rotten must be thrown away. Cars that break down endanger pedestrians.  I can't quite put my finger on the rule which determines when 'that' must be used.  What is it?


In S8E5, we saw that the Lannister forces on the inside gate had surrendered (and so had the city when the bells were rung). Despite this, Daenerys decided to incinerate the city. Why? Was it that the "Targaryen Madness" finally took her, or is she still the old Dany but felt a tremendous urge to avenge?

In Game of Thrones S8E5, Daenerys goes on full killing mode and destroys the entire city in spite of the bells ringing, indicating Cersei surrendering.  (It's evident everyone knows the bells ringing means surrender, including Dany.) But even after Cersei and King's Landing surrendering, why did Dany go ahead and destroy the entire city?  There is grief, and then there is rage, and then there is madness. We have seen her handle grief and anger almost always well. The only times she's unreasonably ruthless is when she kills the Tarlys.  So why did Dany do this in spite of all the pep talk from all her advisers and the bells ringing?


I'd like to export my 3D models in Blender to .U3D file format so that I can place them inside PDFs. I could use this at work when I send reports to clients, in my resume, etc. There is an old plugin that does this, but it doesn't work anymore. Has anyone out there made a plugin/fixed the old one?

I would like to have a way of getting the design sheets(aka blueprints) like you can in CAD software.  Is there a plugin or addon or some form of python script that can export a PDF(vector screenshot) of the GUI(primarily the 3D view)?


I'm getting Null Pointer Exception while retrieving Primary Key or Id of an Entity in Hibernate result query.   My Entity class:  @Entity @Table(name="sample") public class ccy{  @Id @column(name = "S_ID") private long id;   2nd varibale and so on   when i write hibernate query to retrieve it causes Null pointer exception, my select query is:  long ID = 0; String HQL = "select id from sample"; Query query = session.createQuery(HQL); ID = (Long)query.uniqueResult(); //getting NullPointerException in this line  return ID;   Any suggestions to avoid this exception? I'm stuck here. Any help would be much appreciated

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


In any terminal there is specific meaning of puneet@Puneet-Ubuntu-PC:~$I want to replace '$' symbol with '>'.   Please guide me How can I make this change.

How can I change prompt name seen at terminal?  my prompt :  <user_name>@<user_name>-MEGA-BOOK-VR320:~$   It is too long. I want to change it to:  gcc :    However, I should see the path when I go from one directory to another.  gcc :~$ cd X_directory gcc :~/X_directory$   How can I do that, permanently?


I understand that if you have a linear transformation from $U$ to $V$ with, say, $\operatorname{dim} U = 3$, $\operatorname{rank} T = 2$, then the set of points that map onto the $0$ vector will lie along a straight line, and therefore $\operatorname{nullity}T = 1$.   Can anyone offer an intuitive explanation of why this is always true?

I'm having a hard time truly understanding the meaning of $\dim\operatorname{Im} T + \dim\operatorname{Ker} T = \dim V$ where $V$ is the domain of a linear transformation $T:V\to W$. I've used this equation several times in many problems, and I've gone over the proof and I believe that I fully understand it, but I don't understand the intuitive reasoning behind it. I'd appreciate an intuitive explanation of it.  Just to be clear, I do understand the equation itself, I am able to use it, and I know how to prove it; my question is what is the meaning of this equation from a linear algebra perspective.


I am trying to make the negation of the $\gg$ sign in latex. I believe that it exists since It is on my homework sheet that appears to be typed in latex. I tried to draw the sign in detexify, but it did not give me anything. I also tried searching some tables of binary relation signs for latex but I could not find anything.   Thanks for the help, Gabe

I want to negate the symbol whose code is \models (this would be specific to Formal Logic). How can I do that? I tried a number of combination, but didn't find how this could be done. I tried \neqmodels, \nemodels, \notmodels, \nmodels  but all of them are wrong.  Is there a general way to negate symbols?


I would like to implement closed form of PPCA (). In this paper they calculate $W$ in formula (15):  $W=U_q(K_q-\sigma^2I)^{1/2}R$  where $K_q$ is a matrix from eigenvalues $\lambda_i$ of covariance matrix as defined in formula (5).   On one hand I , that it is possible to calculate eigenvalues with  $\lambda_i = \frac{s_i^2}{n-1}$  Is it true, that principal values depend on number of samples $n$?  On other hand I found python implementation of closed PPCA on github, , where it is written      mu = np.mean(self.y, 1)[:, np.newaxis]     [u, s, v] = np.linalg.svd(self.y - mu)     ...     else:         ss = s[:self.q]     ss = np.sqrt(np.maximum(0, ss**2 - self.prior_sigma))     w = u[:, :self.q].dot(np.diag(ss))   where author is apparently calculating with  $\lambda_i = s_i^2$  which is completely different.  UPDATE  Here $s_i$ is diagonal element of singular values matrix.   UPDATE 2  I have tried numeric example  X = np.float64(np.array([     [-1, -1],     [-2, -1],     [-3, -2],     [1, 1],     [2, 1],     [3, 2]]))  n_samples = np.shape(X)[0]  X -= np.mean(X, axis=0)  pca = PCA(n_components=2) pca.fit(X)  cov_matrix = np.dot(X.T, X) / n_samples  singularvalues = pca.singular_values_  for i in range(len(pca.components_)):     eigenvector = pca.components_[i]     eigenvalue = np.dot(eigenvector.T, np.dot(cov_matrix, eigenvector))     singularvalue = singularvalues[i]     eigenvalue2 = singularvalue**2 / n_samples     print("%f\t%f;\t%f" % (eigenvalue, singularvalue, eigenvalue2))   output  6.616286    6.300612;   6.616286 0.050381    0.549804;   0.050381   and found that answer depends on covariance matrix normalization.  UPDATE 3  In the other hand it is written in Python's :     The rows of v are the eigenvectors of a.H a. The columns of u are the   eigenvectors of a a.H. For row i in v and column i in u, the   corresponding eigenvalue is s[i]**2.   UPDATE 4  Ah, sure, a.H a is "scatter matrix", i.e. covariance matrix w/o normalization.

I am having some problem in computing SVD and PCA in Matlab. I do not know if I am doing theoretical mistakes or programming mistakes.  Starting with a data matrix $X$, PCA computes the eigenvalues $\lambda_i$ of the covariance matrix $X^TX/(n-1)$.  On the other side SVD of $X$ is given by  $X=U\Sigma V^\top$, and so $$X^T X=V \Sigma^T U^T U\Sigma V^T=V \Sigma^2 V^T,$$ where $\Sigma$ is diagonal matrix of singular values with elements $\sigma_i$.  So we have that $$\lambda_i=\sigma_i^2 /(n-1).$$  Now I try a Matlab example:      load hald;     [u s v] = svd(ingredients);     sigma = cov(ingredients);     [a,b] = eig(sigma);     disp('sigma')     disp(diag(s)')     disp('lambda')     disp(diag(b)')   and here is the output:   sigma   211.3369   77.2356   28.4597   10.2667  lambda     0.2372   12.4054   67.4964  517.7969   The obtained values do not respect the original equation. Where is the mistake?


I have a computer running Windows 10. Because I wanted to use an Ubuntu based OS, I installed Kubuntu on an external SSD. I have a Lenovo y50-70 laptop, which has a button (next to the power button) that allows one to select which hard drive to boot without going directly to the internal hard drive. In the past I had done this and had no problems. However this time something went wrong.  If I have the hard drive connected to my computer when powering it up, I get the GRUB menu that allows me to select which OS I want to use. When I do not have it connected, I get the following message:  error: no such device: 43519df1-eaa6-4ae44-74b9d66931ff. error: unknown filesystem. Entering rescue mode... grub rescue> _   What I wanted (and what I was able to do in the past) is that when I normally boot my machine (regardless if I have the hard drive connected or not) that it will boot my Windows. When I want to use Kubuntu, I need to use the special "Boot menu" (by pressing the button next to the power up button) while having the device connected.  For some reason GRUB became the default booting system and I don't know how to make the system go directly to the Windows loader. For me to enter Windows now, I need to have my SSD connected as to allow GRUB to be found. How can I fix this?    I don't think this is a duplicate of the question  because this is not a normal dual-boot. My Kubuntu is installed on an external drive and during the process the Windows bootloader was replaced. Now I can't boot Windows (which is inside the laptop's hard drive) without having the external one connected. That being said, they have same similarities which could be argued to be enough for this questions to be a duplicate.

I had Ubuntu 12.04 Beta installed on my computer. When 12.04 was finally released, I made a bootable USB Flash Drive using Startup Disk Creator.  Then I decided to check if this drive works properly and to reinstall the system on my desktop. I must add, my desktop behaves a bit strange when it comes to bootable USB's, it recognizes them as HDD.  In BIOS I changed priority of boot so USB Flash Drive (recognized as HDD) was first. Successfully booted, I installed Ubuntu. Everything worked fine, but...  Now I cannot boot from my real HDD. Every time I want to boot, I put the USB Flash Drive into my computer, boot, safely remove it and everything works.  What do I need to do to repair boot?


I want to install Lubuntu on an old Laptop. I want to work with python, so I have to use stuff like virtualenvs and so. Therefor I need Terminal commands like apt-get. Do these work similar on lubuntu and ubuntu??

What different Ubuntu derivatives are there? And what is special with them?


I'm making a basic array class in VS2015. It initially worked when the function code was in the header file, but now that I've moved that over to a .cpp file I get a C1004: unexpected end-of-file found for the header file.  Array.h:      #pragma once      template <class T> class Array     {     private:         T *m_data;         int m_length;      public:          Array() : m_length(0), m_data(nullptr) {}          Array(int length) : m_length(length);          Array(Array<T>& copyArray) : Array(copyArray.size());          ~Array();          void clear();          T& at(int index);          T& operator[](int index);          int size();     };   Array.cpp:  #include "Array.h"  template<typename T> Array::Array(int length) : m_length(length) {     m_data = new T[m_length]; }  template<typename T> Array::Array(Array<T>& copyArray) : Array(copyArray.size()) {     for (int index = 0; index < copyArray.size(); ++index)     {         at(index) = copyArray[index];     } }  template<typename T> Array::~Array() {     delete[] m_data;     m_data = nullptr; }  template<typename T> void Array::clear() {     delete[] m_data;     m_data = nullptr;     m_length = 0; }  template<typename T> T& Array::at(int index) {     if (m_data != nullptr)     {         if (index < m_length && index >= 0)         {             return m_data[index];         }         throw OutOfBoundsException;     }     throw NullArrayException; }  template<typename T> T& Array::operator[](int index) {     if (m_data != nullptr)     {         if (index < m_length)         {             return m_data[index];         }         else             throw "Out of array bounds";     }     else         throw "Array is null"; }  template<typename T> int Array::size() {     return m_length; }

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.)


What kind of package / font should I use to get the following version of the capital N in math mode?    This is the standard notation for the normal sheaf associated to the divisor D.

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


I had made a big animation in my laptop but now the problem is the process of rendering, I can't render in my laptop because it is 2GB RAM. So is it possible to copy it in another laptop and render it?

I'm moving all files to a new computer, via an external hard drive. I am certain that broken links will be a concern. What can I do to fix this? Is there a 'Best Practices' kind of way to prevent this problem beforehand? I have many hundreds of .blend files, and of course, I fear losing them.


In the book of The elements of Real Analysis by Bartle, at page 220, it is asked that     If $f''(a)$ exists, then $$f''(a) = \lim_{h\to 0} \frac{ f(a+ h) -  2f(a) + f(a-h)  }{h^2}$$   I have proved a similar result for the first derivative of $f$, but I'm not able to show this result for the second derivative of $f$.  I have seen  this question, and it gives a proof for this question, but what I'm asking is that how can we prove this result without exploiting the Darboux property, and using the given hint in that question, and without using Taylor's theorem.  Edit:  Note that I want to see how can this result be obtained only using algebraic manipulations.

Prove: if $f''(x_0)$ exists then $\lim\limits_{x \rightarrow x_0} \dfrac{f(x_0+h)-2f(x_0)+f(x_0-h)}{h^2} = f''(x_0)$.    I'm not exactly sure how Taylor's theorem fits into all this, but I found the first derivative, and I haven't been able to progress past that.


I am looking for a quicker way to add points. I am mapping the buildings on a satellite imagery, but every time I add a point, I need to press enter to close the action menu.  Is there a way to add points without going through the action menu?

Any time I am inserting new point feature in QGIS, the Feature Attribute dialog box is popping up. Is there a way to prevent it? (I am willing to insert many points at once and this pop up box slows down the process).


I have a Nikon D5100 and some beautiful old Cosina lenses (completely manual) What sort of adapter do I need to buy to use these lenses?

I've got some lenses of brand X, but I've just got a new camera of brand Y. How can I tell if it's possible to use my lenses on my camera? I accept that I may lose a lot of automatic functionality like autofocus, aperture control and metering when using an adapter to connect the two.


If $|z_{1}|=2,|z_{2}|=3,|z_{3}|=4$,then find maximum value of $|z_{1}-z_{2}|^2+|z_{2}-z_{3}|^2+|z_{3}-z_{1}|^2$.  My attempt:I considered 3 circles having centre origin and radii as $2,3,4$. Then I tried invoking the triangle inequality $|z_{1}-z_{2}|\leq|z_{1}|+|z_{2}|$ where equality occurs if origin,$z_{1},z_{2}$ are collinear with origin lying between $z_{1}$ and $z_{2}$. This means that $z_{1}$ and $z_{2}$ lie lie on a common diameter with origin lying between $z_{1}$ and $z_{2}$ and thus maximum value of $|z_{1}-z_{2}|$ will be $2+3=5$. If I apply the same reasoning to $|z_{2}-z_{3}|$, I get $3+4=7$.  So now I have  $|z_{1}-z_{2}|^2+|z_{2}-z_{3}|^2+|z_{3}-z_{1}|^2$.  $\leq 5^2+7^2+|z_{3}-z_{1}|^2$.  Not able to proceed from here bcoz if I apply the same logic it will put $z_{1}$ and $z_{3}$ on different sides of origin due to which $z_{1}$ and $z_{2}$ will lie on same side of origin wich is in contradiction to the very first assumption that origin,$z_{1},z_{2}$ are collinear with origin lying between $z_{1}$ and $z_{2}$.

If $z_{1},z_{2},z_{3}$ are three complex number Such that $|z_{1}| = 2\;\;,|z_{2}| = 3\;\;, |z_{3}| = 4\;\;$ Then $\max$ of $|z_{1}-z_{2}|^2+|z_{2}-z_{3}|^2+|z_{3}-z_{1}|^2$  $\bf{My\; Try::}$ Let $z_{1}=2\left(\cos \alpha+i\sin \alpha\right)$ and $z_{2}=3\left(\cos \beta+i\sin \beta\right)$ and $z_{3}=4\left(\cos \gamma+i\sin \gamma\right)$ So $$f(\alpha,\beta,\gamma) = 58-\left[12\cos(\alpha-\beta)+24\cos(\beta-\gamma)+16\cos(\gamma-\alpha)\right]$$ Now How can I calculate $\max$ of $f(\alpha,\beta,\gamma)$ Help me Thanks


I would like to include on my website the thumbnail version of thousands of images created by a third party, which I am trying to contact to ask permission, with no success. I would link from the thumbnail to the original version, hosted in the webservers of this third party, and I would be always citing the original author.  The images are generic landscapes, related to the topic of my website (Africa). I created a thumbnail version, resizing the original dimensions (1024x682) to a square 150x150 pixel cropped thumbnail. These thumbnails, with part of the original image, would be hosted in my webserver.  The third party created millions of images, and I've selected only a part of the original dataset, only those images related to the topic of my website. The purpose is offer information about Africa to the users of my website, linking these original images.  I wondered if this action could be considered as a 'Fair Use' of the contents, in order to avoid legal issues with this third party. I've reading , but I would like to know other point of views.

Lets say I write a blog post about the new Batman movie or a the new Grand Theft Auto game and i decide to use the boxart/poster or a wallpaper as the main image for the blog post,  can I be sued for breach of copyright on this image?  Im pretty sure Warner Bros are going to be hunting anyone down even if it is legal, but is this actually legal? If i buy the DVD or Game and take a picture of it, is this my copyright? When a trailer gets released and put on youTube, can i take a screenshot of this video and use this as an image?  It seems people can get rightly screwed for this, so I would like to know where i stand on this sort of thing.


I'm using Biblatex and biber for my citation needs, but I have the problem, that one citation remains undefined, if I cite more than 3 authors, with 3 it shows up, with more than that it is undefined! Anyone had this problem and knows a solution?

I use  to store all articles I need and bibtex4word add-on (in MS Word) to maintain the reference list. So, I would like to know how to properly fill the "author" field in Jabref with multiple authors to appear them correct in the reference list.  For example, I've got the article with several authors:      E. Orti, J.L. Bredas, C. Clarisse   And I would like them to appear in this manner. But instead I get this:     C. C. E. Orti, J. L. Bredas


I'm fairly new to Drupal theming, and I am trying to customize the HTML output the Flag module for Drupal 8 produces for flag/unflag links; more specifically, I would like to make the links appear as buttons using Bootstrap classes. Does anyone know a good way to do this? I'm placing the flag link on the user profile page to enable users to follow other users. Here are some approaches which I have tried, so far without success:   Using the Twig replace filter to modify the output. This does not work, apparently because a "lazy builder" is used, delaying the production of the actual HTML output until a later stage after Twig's rendering is already complete. Overriding the flag.tpl.php template with a customized version. This has no effect; maybe this functionality is no longer active in Drupal 8 (which did away with PHP templates in general)? Using flag_create_link in a theme preprocess function. I got an error that this function does not exist; maybe it no longer exists in the Drupal 8 version of the module? (or else maybe I'm missing a necessary import).

I'm working on a 'sample request' implementation for a commerce site using , , sessions and a little custom code.  I'd like to add an icon or a symbol to let people know that an item they are viewing has been flagged.  I'm not sure exactly how to approach this, I can imagine perhaps adding a conditional field that displays an image or check box that is then changed by  or ajax, or perhaps something more complicated in JavaScript?  It could really be as simple as adding a checkbox that is checked or unchecked as the flag link is clicked or maybe even changing the css/html on click to be identified as marked.   Anyway, grateful for any advice here.


I have been looking for a "layman" version of the license for the Free Hyper-V 2012, and more precisely, what services you are allowed to run on the host.  The OS itself does not prevent you from installing a variety of applications and services, but I wonder how legal this is.  You can install 3rd party virtualization managers or servers (anything based on http.sys will run f.i, and so will 3rd party FTP or mail server). For that matter you can even install alternative desktop shells, explorers, browsers and utilities etc. so the OS itself does not prevent installation of any 3rd party software, only the OS components are missing.  My particular purpose would be to know if the license allows to use the Free Hyper-V 2012 as a "bare-metal" OS for hosting simple web services (based on http.sys or raw sockets rather than IIS), that would otherwise require a full Windows 2012 server. Virtualization functions would not even be used.

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


I have a situation where I pass an array containing 2 1 byte values to a function, but somehow the function thinks the array is 4 bytes long, which messes up my bit manipulation big-time. I even tried explicitly casting each array value as a uint8,but to no avail. Any ideas about what might be happening? Using cygwin's gcc tools on Eclipse Mars.1.  typedef char uint8; //char is 1 byte in my system.  void setBitArray(uint8 bitArray[], int first, int last, uint8 type) {     if(first >= 0 && last < sizeof(bitArray) * 8) { // If the block is in bounds         ...     } } ... int main() {     uint8 bitArray[2] = {(uint8)0, (uint8)0};     setBitArray(bitArray, 0,10, 1);     return 0; }   EDIT  One more thing. sizeof(bitArray) yields 2 bytes in main().

How do I determine the size of my array in C?   That is, the number of elements the array can hold?


Suppose that an r.v $Y$ has the property that, for any $b$ greater than one, conditional distribution of $Y/b$  given that $Y$ is greater than $b$ is the same as the distribution of $Y$. what are the possible distributions of $Y$ and their expected values? I am thinking of exponential and Gamma, since they have the memoryless properties. But I really have trouble writing down the conditional distribution of $Y/b$, I messed up with the transformation. Appreciate your help!

Question Suppose that a random variable $X$ has the property that, for any $a > 1$, the conditional distribution of $\frac 1 a X$ given that $X > a$ is the same as the distribution of $X$. Specify all possible distributions of $X$. My thoughts I do know that $f_{X\mid Y}(x\mid y) = \frac {f_{X, Y}(x,\ y)} {f_Y(y)}$ and I suppose I have to make use of this relationship, but I have no idea how to even begin - When I find conditional distributions, I am usually given a specific value, not something like $X > a$. Any proposed solutions with intuitive explanations will be greatly appreciated :)


There is literally no download link except for the bittorent file. Can anyone link me the direct download?

Please could someone tell me where can I download Ubuntu 32bit without using a torrent? Thanks


I have created 100 GB for /. When I opened Nautilus I have found the root folder. So what is difference between / and /root?  My username is enigma, and I have a folder named enigma in the /home folder and another folder with the same name in /media. What is the difference between these two folders and when do I have to use the second folder?

In Windows there’re perhaps only a couple of important folders (by important I mean important in my logical picture of the Windows file system) in the installation drive (in my case C:\). Namely Program Files and Windows. I simply stay away from Windows folder and the “add remove program files” is good enough to handle the program files folder of Windows. Of course there’s a folder named Users where the users (who are not admins) can access only their folders.  Thus there’s a clear picture at some level in my mind of the Windows file system. In Ubuntu, when I reach the location /, there’s a huge list of folders, most of which I have no clue as to what they contain. The /bin folder seems to be the equivalent of the Windows folder in windows. The /usr folder seems like it’s the equivalent of the Users folder in Windows. But even the /home folder looks like it can fit the bill.  Please understand that I do understand, that Ubuntu (Linux) has a different character than that of Windows, i.e., there need not be exact equivalent of Windows functions, in Ubuntu. All I am looking for is a bit more clearer picture of the Ubuntu file system.   This question is a part of a bigger question which I am splitting up to make it more answerable. The original question can be found here:


Any quantum state must be a square integrable function in order for it to be allowed. Is there any reason that this should be so? As far as I am aware, other $L^p$ spaces can have norms defined on them in a similar way to the norm of $L^2$.  Is it just experimental fact that the probability of a position measurement, say, is given by$\int |\phi (x)| dx$, or is there some more foundational reason to restrict quantum states to $L^2$.  I apologize if I am unclear, I feel like I may be missing something fundamental here.

I asked this question for many people/professors without getting a sufficient answer, why in QM Lebesgue spaces of second degree are assumed to be the one that corresponds to the Hilbert vector space of state functions, from where this arises? and why 2-order space that assumes the following inner product:  $\langle\phi|\psi\rangle =\int\phi^{*}\psi\,dx$  While there is many ways to define the inner product.  In Physics books, this always assumed as given, never explains it, also I tried to read some abstract math books on this things, and found some concepts like "Metric weight" that will be minimized in such spaces, even so I don't really understand what is behind that, so why $L_2$? what special about them? Who and how physicists understood that those are the one we need to use?