When deleting low quality answers from the review queue, you get the option to leave a standard comment, chosen from a list. I find it very convenient, and I think it would be useful to have the same feature when handling flagged posts, or also just browsing.  Is there a reason not to have pre-compiled comments?

My  script has now gained quite a following (and it - allegedly - just got bust by upgrading to jQuery 1.7.1). This is a personal request to the team to consider adopting it.   Not that I don't wish to keep on maintaining it, but the next step (allowing users to define one global set of comments to be used across all their sites*) is pretty awkward for me to implement "from the outside", but would be comparatively trivial for the team (I believe).  Goes off to fix script...  * Note: I have a beta half-version of this; it requires   userscripts, and allows you to push/pull between "local" (site-specific) and "global" storage. And even if I get the global sharing 'properly' working, it would still only be for a given machine.


My son was in a wreck and his phone was crushed is there any way I can find out what was on the phone if I connect it to my computer

My Android device screen got broken and I can't see what I'm doing. That's the only wrong thing with my device, the rest is apparently working OK. Is there any way to send my device screen to my computer? I don't want to work blindly anymore!


In an earlier question I learned the following code to define conditionally compiled text (for a teacher guide)  \newtoggle{teach} \toggletrue{teach} \NewEnviron{teachr}   {\iftoggle{teach}{\BODY}{}} \newcommand{\cpp}{\begin{lstlisting}[language=C++]}   If I want to embed code within this conditionally compiled text, it fails. Conditional text works fine.  \begin{teachr}  \cpp class foo {}; \end{lstlisting}  \end{teachr}   The error message is:     ! LaTeX Error: \begin{teachr} on input line 166 ended by \end{lstlisting}.  I assume this is some obvious failing, but if I should construct an mwe let me know and I will edit the question.

I have a problem with the lstlisting package. I want to define an \newenvironment with one obligatory parameter, which will be the caption name for the lstlisting. I will also have other lstlisting environments, that is why I am trying to define them separately.  I am also having some difficulties with \lstinline command (I set up a \newcommand to gain easier coding), which typesets keywords in normal text. Why can't it be in captions and similar?  I suppose something could be wrong with the preamble, that's why all the packages used are listed.  \documentclass{book} \usepackage[a4paper, top=3cm, bottom=3cm, heightrounded, outer=3cm, inner=3cm, marginparwidth=1.5cm, marginparsep=0.5cm]{geometry}  \usepackage{tocloft} \usepackage{amsmath}  \usepackage{eurosym} \usepackage{url} \usepackage{array} \usepackage{tabularx} \usepackage{multirow}  \usepackage{multicol}  \usepackage{graphics} \usepackage[dvips]{graphicx}  \usepackage{epstopdf}  \usepackage[dvipsnames]{xcolor}  \usepackage{verbatim} \usepackage{fancyvrb}  \usepackage{fancyhdr} \usepackage{paralist}  \usepackage{listings}  \usepackage{pifont}  \usepackage{indentfirst}   \lstset{language=[Visual]Basic, % keywordstyle=\color{blue},commentstyle=\color{ForestGreen},stringstyle=\color{Maroon},% basicstyle=\ttfamily\normalsize, frame=lines, % showspaces=false, showstringspaces=false,% tabsize=4, aboveskip=10pt, belowskip=10pt, % lineskip=2pt, numbers=left, numberstyle=\tiny, stepnumber=1, numbersep=5pt,% numberblanklines=false, % breaklines, breakatwhitespace, prebreak=\_, breakindent=0pt % }  \lstset{morekeywords={Or, Loop, Until, To, As, Single, Module, Double, ByVal}}  \lstset{emph={Console}, emphstyle=\color{Aquamarine}}  \newenvironment{case}[1]{\renewcommand\lstlistingname{Case}% \begin{lstlisting}[caption={#1}]}% {\end{lstlisting}}  \newcommand{\code}[1]{\lstinline[basicstyle=\rmfamily\normalsize, prebreak=, keywordstyle=\ttfamily]{#1}}   \begin{document}  Example with inline, that works: \code{Console, Sub in Module}.  \begin{case}{Hello world} %doesn't work Module Module1     Sub Main()         Console.WriteLine("Hello World!")         Console.ReadKey() End Sub End Module \end{case}  \end{document}   Thank you in advance!


Let $p \neq 3 $ be a prime. Prove that $ p = a^{2} + ab +b^{2} \ a, b \in \mathbb{Z} \iff p \equiv 1 \ mod  \ 3$.  The $\rightarrow $ direction is easy. For the other implication, I considered $\mathbb{K} = \mathbb{Q}[\sqrt{-3}] \ $. Then $\mathbb{O}_{\mathbb{K}} = \mathbb{Z}[\frac{1+\sqrt{-3}}{2}] = \mathbb{Z}[\theta] \ $ so for $\alpha = c +d\theta \in \mathbb{Z}[\theta]$ we have that $N_{\mathbb{K}|\mathbb{Q}}(\alpha) = c^{2}+cd+d^{2}$ and we can use the Kummer-Dedekind theorem.   The minimal polynomial of $\theta$ is $f(x) = x^{2}-x+1$ but how to do the reduction of $f(x) \  mod \ p $ ?

I came across a claim that I found interesting, but can't seem to prove for some reason. I have the feeling it should be easy  a prime $p$ can be written in the form $p = a^2 -ab +b^2$ for some $a,b\in\mathbb{Z}$ if and only if $p\equiv 1\bmod{6}$


Let $H$ be a subgroup of $G$.   $S=\{g\in G\mid ghg^{-1}\in H,\forall h\in H\}$.   I know that $N_G(H)\subset S$. But I can't seem to find any counterexamples for the other inclusion. Any ideas?

Let $G$ be a group, $H\subseteq G$ a subgroup and $a\in G$ an element of the group. Is it possible that $aHa^{-1} \subset H$, but $aHa^{-1} \neq H$?   If $H$ has finite index or finite order, this is not possible.


How can I simulate transactions in REST?  I have just developed the back-end with Jersey, Spring, Spring Data for data access, which connects to a MySQL DB. My goal is to show(like a test) that it can handle database transactions, but can't imagine how to do it.

I'm wondering how you'd implement the following use-case in REST. Is it even possible to do without compromising the conceptual model?  Read or update multiple resources within the scope of a single transaction. For example, transfer $100 from Bob's bank account into John's account.  As far as I can tell, the only way to implement this is by cheating. You could POST to the resource associated with either John or Bob and carry out the entire operation using a single transaction. As far as I'm concerned this breaks the REST architecture because you're essentially tunneling an RPC call through POST instead of really operating on individual resources.


Please help me to solve this problem. I can find almost no clue regarding the log part. I tried to break the $\binom{2n}{n}$ part, but in vague...will the breaking help me in anyway?

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


Let $f:[a,b] \to \mathbb{R}$ be continuous on $[a,b]$ and   differentiable on $(a,b)$. Show that $\lim_{x \to a} f'(x) =  A > \Rightarrow f'(a)$ exists and equals $A$   I am unable to think of any way to solve this problem  I tried using mean value theorem on $[a,x ]$ for $a < x < b$   $\exists \; c \in ]a,x[ \; \Rightarrow f'(c) = \frac{f(x)-f(a)}{x-a} \Rightarrow \lim_{x \to a} f'(c) = \lim_{x \to a} \frac{f(x)-f(a)}{x-a} $  Now the RHS represents $f'(a)$ but how does it equals $A$? because $f'(c) $ is a constant

Let $f$ be a real-valued function continuous on $[a,b]$ and differentiable on $(a,b)$. Suppose that $\lim_{x\rightarrow a}f'(x)$ exists. Then, prove that $f$ is differentiable at $a$ and $f'(a)=\lim_{x\rightarrow a}f'(x)$.    It seems like an easy example, but a little bit tricky. I'm not sure which theorems should be used in here.    ==============================================================  Using @David Mitra's advice and @Pete L. Clark's notes I tried to solve this proof. I want to know my proof is correct or not.  By MVT, for $h>0$ and $c_h \in (a,a+h)$ $$\frac{f(a+h)-f(a)}{h}=f'(c_h)$$ and $\lim_{h \rightarrow 0^+}c_h=a$.    Then $$\lim_{h \rightarrow 0^+}\frac{f(a+h)-f(a)}{h}=\lim_{h \rightarrow 0^+}f'(c_h)=\lim_{h \rightarrow 0^+}f'(a)$$   But that's enough? I think I should show something more, but don't know what it is.


I'm trying to create a sine function that will fit a geochron clocks day/night line. Right now I just started with a simple sine function, using map coordinates, which is this y=69sin(x-15)+2 but the peaks of the function should be flat which was not achieved with this function. Any advice on how to relatively easily transform the function to get this effect?   This is the online geochron clock that I was looking at

Basically, I have a program that will graph the day/night shade similar to this page:   Could any of you give me the equation for graphing a line that approximately follows the day/night curve. I can't really think of an equation, so I'm asking here. Thanks.


Which is the best choice and why for formatting a USB3 memory stick? FAT32 was the out of the box, but the file size limit is a to small.   FAT32  NTFS exFAT   Size, speed and stability are good measurements.  Im using a SanDisk Extreme memory stick.

So, basically I always format my removable mass storage devices as NTFS by default, but someone told me I was better off using exFAT. Now I've been looking around google, but can't find any good reasons why I should.  Is there anything that exFAT does (better) which NTFS doesn't which is useful when using it for (>4GB) removable mass storage?


I just came across this link.   But I did not understand what exactly are those and how is it useful.

Attention mechanisms have been used in various Deep Learning papers in the last few years. Ilya Sutskever, head of research at Open AI, has enthusiastically praised them:    Eugenio Culurciello at Purdue University has claimed that RNNs and LSTMs should be abandoned in favor of purely attention-based neural networks:    This seems an exaggeration, but it's undeniable that purely attention-based models have done quite well in sequence modeling tasks: we all know about the aptly named paper from Google,   However, what exactly are attention-based models? I've yet to find a clear explanation of such models. Suppose I want to forecast the new values of a multivariate time series, given its historical values. It's quite clear how to do that with an RNN having LSTM cells. How would I do the same with an attention-based model?


If we have a function defined from $[a,b]$ to the complex numbers, does that function being Lebesgue measurable imply it is also integrable? (a member of $L^1$?)

For an arbitrary interval $I$, how can we find a positive on $I$ integrable function? And how does one construct a measurable but not integrable function. If not all measurable functions are integrable, what is the best way to determine if a function is L-Integrable?   thx in advance


When editing an answer, the "new revision" message is shown for a short moment. This makes no sense because the revision you just created is automatically displayed anyway.

One screenshot will explain it the best:    It shouldn't be there - appeared right after posting the comment. When reloading the page it disappears so something goes awry with the AJAX handling.  Clicking it is reloading the existing comment(s) and open the new comment text box.


I just want to know how can I write this equation in latex? I mean the equation in the picture, how much description should I make?

I want to write a conditional expression such as the following.    What is the best way to express such conditional expressions in Latex?


Instead of using  \usepackage{listings} ... lstinline{for} or \lstinline{while} or \lstinline{main} Here you \codeword{see} an \codeword{example} of \codeword{code}   how is it possible to define this syntax for inline-code, similar to Markdown:  Here you `see` an `example` of `code`   ?

On any SE post one can use the backtick symbol ("`") in order to mark some text as being a piece of code, or computer output. For example: void main().  Is there a way to make use of "`" the same way in a LaTeX document?


I'm using algorithm and algpseudocode and want to split up the algorithm. Therefore I want the code parts to be at the position I'm explaining them, so I use the floating [H]. But the code starts with two lines when no caption is set (between The calculation is done by and a+b\cdot c) and I want to omit the first horizontal line there. A minimal working example is:  \documentclass[a4paper]{scrartcl} \usepackage{ngerman} \usepackage{algorithm} \usepackage{algpseudocode} \setlength\parindent{0pt}  \begin{document}   Used input is   \begin{algorithm}[H]     \caption{My Sum}     \begin{algorithmic}[1]       \Require $a,b,c$     \end{algorithmic}   \end{algorithm}    The calculation is done by   \begin{algorithm}[H]     \begin{algorithmic}[1]       \State $a+b\cdot c$     \end{algorithmic}   \end{algorithm} \end{document}   results in:

I have something like this:  \usepackage{algorithm} \usepackage{algpseudocode}  ... \begin{document} \begin{algorithm}[H] \begin{algorithmic}[1] \Function {function}{a} \State a = a + 1 \EndFunction \end{algorithmic} \end{algorithm} \end{document}   I'm using [H] because I want to set the position of my code. But after doing that a space for caption appears and I don't want it and now there are to horizontal lines beafore my code. You can see what I mean in this picture:   How can I remove one of those lines?  Thanks!


I said out loud, "I will ride my boat....not if it is raining....if the wind speed is 5mph” Does this mean: I will ride my boat if it is not raining outside and if the wind speed is 5mph. That is, the 2 conditionals “not if it is raining” and “if the wind speed is 5mph” are equal to each other. Or is the 2nd conditional serving as a conditional to the first conditional: If the wind speed is 5mph, then I will not ride my boat if it is raining outside?

If I said, "I will run, not if it is snowing, if I my shoes are comfortable." Does the "if my shoes are comfortable" modify the "I will run" clause? I agree the sentence would be clearer with the addition of "and" in place of the comma. However, without the "and" is it still clear that the "if my shoes are comfortable" clause modifies the "I will run" clause?


I have an issue with a new command I use, to create a new template for a workgroup.   In my main document, I create a new commant like below, to allow my users to define a new word I will put in the front page of their report. I do so, because I don't want them to mess up the huge amount of code in the frontpage.  % create the new command \makeatletter \newcommand\hello[1]{\def\@hello{#1}} \makeatother  % later one, they use this \hello{hello world}   In my front page document, this is called in a footnote like below :  \let\thefootnote\relax\footnote{{  \makeatletter \@hello \makeatother }   The result of this (via pdflatex in texmaker) is that there is hello wrote in the footnote instead of hello world. Note, when I put the \makeatletter\@hello\makeatother in the main text, it works.   Do I have to define the full footnote in my new command ?  Thx in advance

After hours of banging my brain against my skull, I narrowed down an issue I'm having to the fact that \makeatletter doesn't work inside \newcommand. Commands that I call after \makeatletter are registered as undefined, as if \makeatletter didn't do anything.  Why is this the case?  In the example below, I define two commands. Calling one of them from the document body causes the undefined error, while the other doesn't.  \documentclass[11pt]{book} \usepackage{kvsetkeys}  \newcommand{\commandThatFails}{     \makeatletter \comma@parse{}{} \makeatother }  \makeatletter     \newcommand{\commandThatWorks}{         \comma@parse{}{}     } \makeatother  \begin{document}  Hi there.  \commandThatFails \commandThatWorks  \end{document}


I have been writing a chapter of my thesis using Lyx. Everything was normal until I put the last image in the project. When I am trying to generate the DVI file I got this error message:  LaTeX Error: 'File 8D_***path to my image***'.  LaTeX Error: Cannot determine size of graphic in 8D_***"location of the image inside the .lyx file"***.   I don't understand why this happening because this image has the same extension of the other (.png), besides is not bigger than some of those. I tried to put the image in the same folder but this did not work, I also changed the extension to .bmp but it was worse.  What could happen?

I want to import graphics into my main input file using the macro \includegraphics. It does not work if the filename contains spaces.   also discusses this subject, but there is no solution there.  My compilation routine is latex->dvips->ps2pdf (because of PSTricks).


My husband, my kids age 9 and 4 and I plan to visit US for my brother's wedding. Can you please advise if we need separate DS-160 form for each one of us as in each separate application or just the 1st applicant can say add family and complete the details or both has to be done fill separate forms and also fill the details by adding family. How do I get everything linked together for payment and visa interview together? I am very confused, step by step help will be much appreciated.

I'm going to travel with my spouse to the US for visiting. and I want to apply for B1/B2 visa. I filled an application for myself. Do I need to fill a separate DS-160 form for her? If so, how can I link these two applications?


I run a rolling backward stepwise factor selection within each regression window with a Matrix of regressors X(137x481) and a vector Y(1x137). As you can see, the number of regressors is way higher than the number of datapoints  Looking at the rolling R^2 I noticed that is Always extremely high. This lead me to the conclusion that the model is overfitting the data.   The reason is probably related to the high number of covariates and the multicollinearity problems that comes with.  Why the stepwise regression has this problem when there are many data? Reducing the number of covariates, I noticed an improvements. How can I effectively avoid this problem while maintainig a rolling selection criteria based on statistical significance? Doing a before will make any sense?  Thank for your help

I am experimenting with stepwise regression for the sake of diversity in my approach to the problem. So, I have 2 questions:   What are the advantages of stepwise regression? What are its specific strengths? What do you think about hybrid approach, where you use stepwise regression to select features, and then apply regular regression taking all the selected features together?


I have  followed the instructions •Reset Network Settings by tapping Settings > General > Reset > Reset Network Settings. But prior to tapping "reset network settings" I want to be sure that I do not have my data deleted in the process. In other words it will not go back to factory settings will it? I made that error once and cost me much work wise.

I use "internet sharing" on my Mac, but lately I've been having trouble connecting my iPhone 5 to the resulting WiFi network. I've read advice online to do Settings -> General -> Reset -> Reset Network Settings on the iPhone, but I can only find very vague information on what this actually does. From the name it sounds like a bit of a nuclear option, and before I try it I want to make sure that it's not going to affect my ability to use the cellular network.  So, does the iPhone's "reset network settings" just reset WiFi settings, or does it reset cellular network settings as well? If the latter, is there any danger that this would delete any settings installed by my phone company, causing problems with using internet or telephone services via the 3G or 4G networks?


In episode 10 of season 2 we witness the encounter between one of the Night King's "officer" and Samwell Tarly.                                   However, since then, Samwell had time to make it back to the wall, meet Gilly and her child, leave the night's watch, travel it to the Citadel, study to become a Maester, leave the citadel etc.   Now, even after all this time, we see in episode 6 of season 7 that the army of the dead has not even reached the wall yet. Considering the fact that the army of the dead is made out of undeads who don't need (or at least I don't think so) to frequently stop to eat or rest, I was wondering how they haven't made it to the wall yet.   I thought that they maybe could've been retained from heading to the wall by the some of the 3 eyed raven's magic, but even then, Bran had the time to make it back to the wall by being pulled by a young girl on a sled.   I feel like I am completely missing out on some basic plot hole and that this question is actually super easy to explain but unfortunately, I truly cannot recall any events that could explain this.  Edit: Regarding the accusations of this question being a duplicate of (). From what I understood, that other question was addressing more precisely why the night king ACTS as slow as he does, notably in ep6 of season 7 when he attacks Viserion. My question is more looking at why it took the night king more or less 5 seasons for him to reach the wall while Samwell did it in barely 1. I researched before posting this question and unfortunately that other question did not answer at all what I am asking here...

Follow-up question to     In "Beyond the Wall" (Game of Thrones, S07E06), the Night King       kills the dragon Viserion with a spear.   Why is he moving so slowly when he could have easily eliminated all targets? Also, in previous episodes, we saw him strolling around, e.g. when attacking Bran's hideout. Is there any in-universe explanation why he is moving slowly, or is he just ... too cool to hurry?  Scope: I'm not asking about this specific episode but in general. We have seen him act slowly in previous episodes.


When I log in to my user account, or guest or any other, I get a black screen and I can see a cursor icon and move it.  But nothing else is on screen, can't run commands with ALT-F2, meta keys don't do anything it seems. I can switch to another console, but the graphical interface does not work.  Even if I create another user account or guest account, it's still the same.  I've installed gnome from terminal (with lightdm though) and it is the same.   What could be the problem here, how can I reset stuff?  I have tried installing gnome, switching to gdm etc.  I have Ubuntu 13.10 installed (about 10 days ago). Didn't do anything funky recently or install new software before the incident, it just got b0rked suddenly.  Update: When I startX from 'nother console, the log says that the stuff is initializing. The last thing done is I see:  Loading extension GLX (II) [KMS] Kernel modesetting enabled. The XKEYBOARD keymap compiler (xkbcomp) reports: > Warning:           Type "ONE_LEVEL" has 1 levels, but <RALT> has 2 symbols >                    Ignoring extra symbols  Errors from xkbcomp are not fatal to the X server

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:


Guess I should have uploaded a picture of the main issue. The problem wasn't that the meshes were darker without materials. So since that wasn't the issue I've cleared up my question a bit.    So the coat was one big mesh, I separated it at the top of where it discolored now. It wasn't discolored prior to the separation, the coat looked fine all the way down. It happened after I had mirrored one side of the bottom and had reattached it to the coat again. The texture is fine, it just has a blue hue to it. And I don't know how how to fix it, even with the materials removed, it still has that blue hue to it.  I tried to recalculate outside and inside which had no effect, other than make it look like it should without material. Just like flipping normals did. Any ideas? (Hopefully I explained it good enough)   I found the issue myself yesterday, it's a texture issue. After merging the vertices, the blue area appeared. It's drawing the material from the wrong place in the UV map. How do I go about changing this, in there a way to easily do this, or do I have to move and scale everything by hand?  In the picture, circled in red. It's supposed to be white, but it's blue since it's taking a texture from another part of the UV map, than the rest.

While rendering a mesh with smooth shading on, I get a dark region/shadow on certain faces. The effect is more evident when smooth shading is applied to a mesh containing ngons, with the ngons turning black when rendered.   The blackening effect is visible in the viewport too.  How can I solve this problem?


Let $\lambda_1, \lambda_2,...,\lambda_n $ be roots of unity and let $z=\sum\lambda_i/n$ be an algebraic integer.  To show:     (a) Any conjugate of $z$ , say $z'$, is of the form $z'=\sum \lambda'_i/n$ where   $\lambda'_i$ are roots of unity.   Note: Conjugate of $z$ is any $z'$ such that the minimal polynomial of $z$ and $z'$ are the same.     (b) Is $z'$ an algebraic integer?   These problems are loosely based on a step in the proof of Burnside's theorem that I am trying to study from the , page $69$ lemma $A.19$. Any help will be appreciated.

Let $\alpha_1,\ldots, \alpha_n$ be roots of unity, and let $a=\frac{1}{n}\sum\alpha_i$. Then if $a$ is an algebraic integer, we have either $a=0$ or $a=\alpha_1=\dots=\alpha_n$. Why?


The question is to show that a circle and a elipse are homomorphic in $R^{2}$.  I have two questions 1) should I consider only the boundary points of circles and elipse?  2) what is the suitable function for this?.

A disk/circle is defined by   $$C = \{(x,y) \in \mathbb{R^2} : x^2 + y^2 \leq r^2\}$$  An ellipse is defined by  $$E = \{(x,y) \in \mathbb{R^2}: x^2/a^2 + y^2/b^2 \leq 1 \}$$  How can we define a function that takes $C$ to $E$?


A while ago, I asked  then kept on searching in the meantime, and found out there was a bug with API and it would be fixed. I stated this in one of my comments. Should I make it an answer?

I might want to answer my own question because:  I arrived at a solution before there were any other correct answers or I like mine better, can I still answer my own question?  I have a folder with lists of code snippets for things I always forget or get wrong, such as regular expressions for processing XML, common WinForms control idioms, etc. Is it considered poor etiquette for Stack Overflow to ask a question I already know the answer to, and then self answer, just so it gets recorded on the website?   Related:          For more information, see "" in the .


I'm looking for a way to achieve the equivalent of chmod 600 on Windows using the icacls utility. For the user part I got the rw permission by using icacls file /inheritance:r /grant:r %USERNAME%:(R,W). Now, I'm having troubles with denying all the other users from any access to the file. I could explicitly deny every existing user but any users created after the denial will still have access to the file. Is there any good way to deny all the users except for me?  Thank you in advance!

What is the Windows equivalent to:  chown $USER chmod 600 file   From what I understand, this requires that inherited permissions be disabled (because HOSTNAME\Users is inherited) and all groups outside of myself and Administrators be removed.  Can this operation be performed with takeown and icacls?


$\det\begin{vmatrix} 0 & \cdots & 1& 1 & 1 \\ \vdots & \ddots & \vdots & \vdots & \vdots \\ 1 & \cdots & 1 & 1 & 0 \end{vmatrix}=?$  Attempt:  First I tried to use linearity property of the determinants such that $$\det\binom{ v+ku }{ w  }=\det\binom{v  }{ w  }+k\det \binom{ u }{ w  }$$  $v,u,w$ are vectors $k$ is scalar.  I have tried to divide it into $n$ parts and tried to compose with sense but didn't acomplish.  Second I tried to make use of "Row Reduction" i.e. adding scalar multiple of some row to another does not change the determinant, so I added the all different rows into other i.e. adding $2, 3,4,\dots,n$th row to first row and similarly doing for all rows we got   $$\det\begin{vmatrix} 0 & \cdots & 1& 1 & 1 \\ \vdots & \ddots & \vdots & \vdots & \vdots \\ 1 & \cdots & 1 & 1 & 0 \end{vmatrix}=\det\begin{vmatrix} n-1 & \cdots & n-1& n-1 & n-1 \\ \vdots & \ddots & \vdots & \vdots & \vdots \\ n-1 & \cdots & n-1 & n-1 & n-1 \end{vmatrix}=0$$  The last determinant is zero (I guess) so the given determinant is zero?  I don't have the answer this question, so I am not sure. How to calculate this determinant?

How do I calculate the determinant of the following $n\times n$ matrices  $$\begin {bmatrix} 0 & 1 & \ldots & 1 \\ 1 & 0 & \ldots & 1 \\ \vdots & \vdots & \ddots & \vdots \\ 1 & 1 & ... & 0 \end {bmatrix}$$  and the same matrix but one of columns replaced only with $1$s?  In the  above matrix all off-diagonal elements are $1$ and diagonal elements are $0$.


So I have a table in MS Word which has two columns. In the second column the text is spread on multiple lines, ie I have pressed 'Enter' to achieve this.  When I paste into Excel, it converts these separate lines into separate cells.  What I want it to do is to keep the lines in the same cell, just on different lines, ie what would happen if I were to press Alt+Enter in a cell in excel.  How would I go about this?  Edit: here's an example of my data. In word it's in a word table.  ---------------------------- | Bananas   | - yellow     | |           | - curved     | ---------------------------- | Apples    | - red/green  | |           | - round      | ----------------------------

I have data in a Word table that includes line and paragraph breaks. When I copy the data into Excel, it splits each line and paragraph I want into multiple cells. How do I copy the data to Excel and keep the breaks?


Mounting external HD Seagate 4 TB in Kubuntu failed with error message:  Error mounting /dev/sda1 at /media/fritz/Seagate Backup Plus Drive: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000" "/dev/sda1" "/media/fritz/Seagate Backup Plus Drive"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sda1': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.  However, mounting with Windows 8.1 was OK.  How can I mount with kubuntu again ?

Whenever I boot Ubuntu, I get a message that it cannot mount my windows partition, and I can choose to either wait, skip or manually mount.  When I try to enter my Windows partition through Nautilus I get a message saying that this partition is hibernated and that I need to enter the file system and properly close it, something I have done with no problem so I don't know why this happens.    Here's my partition table, if any more data is needed please let me know.     Device Boot      Start         End      Blocks   Id  System /dev/sda1            2048    20000767     9999360   83  Linux /dev/sda2        20002814   478001151   228999169    5  Extended /dev/sda3   *   478001152   622532607    72265728    7  HPFS/NTFS/exFAT /dev/sda4       622532608   625141759     1304576   82  Linux swap / Solaris /dev/sda5        20002816   478001151   228999168   83  Linux


Solve $$I=\int_0^1\frac{ln(1+x)}{1+x^2}dx.$$  After let $x=\tan t$, $I=\int_0^{\pi/4}ln(1+\tan t)dt$ and I stuck here.


I'm talking about the OS made for PC. what would happened if I install it on android phone? will it figure out the hardware or is it a guarantee way to kill a phone?  checking if anyone tried before I sacrifice my old phone. this is not a duplicate with ubuntu touch or supported devices! this sticking a laptop OS to phone without source customization

With the announcement of the Ubuntu Phone OS I'd like to know what phone (and tablet) models are supported at this time.  Note from foss & Oli: We are making this the master question for all future "Will this work on <insert random tablet/phone/device here>?!" questions


I need to cut html tags in JSP view on client side.   I have something like this:   <c:forEach items="${myitemsList}" var="temp">    ...
       ${temp}
    ... </c:forEach>   Inside every ${temp} there is some html code like
Some text example
. I need to cut this html tags to have pure text: Some text example.   Of course I could just add model object without html tags but I need to do cut this on client side. Is there any way to do this?  Thanks

Is there a good way to remove HTML from a Java string? A simple regex like replaceAll("\\<.*?>", "")   will work, but things like &amp; wont be converted correctly and non-HTML between the two angle brackets will be removed (i.e. the .*? in the regex will disappear).


I have a question. I'm writing paper in two columns form, but I want to place my figure in centre of page instead of column. How can I do this? Thanks in advance.

If I just try to set the figure's size to 0.9\textwidth my figure will just end up on the right column, sized to be two-columns wide.  Has anyone done this before?


Clearly I am being thrilled with this question boggling in my mind. "Should I root my phone?" What are the pros and cons? Clarify this thing to me, is it dangerous or is it better than I imagine?

This is a common question by those who have just rooted their phones.  What apps, ROMs, benefits, etc. do I get from rooting?  What should I be doing now?


I am creating a document in LaTex and my abstract looks like    The code part is:  \section{Введение}  \textbf{Образцы:} 9 клеточных ...  \textbf{Задача:} Выполнить ...  \textbf{Методы исследования:} Анализ ...   As a result I get Задача and Методы исследований with indentation and Образцы without it. How can I insert it when?   A small update What if I need the first paragraph to be indented and others to be not?

I am just curious that the following format looks good to you or not? The preamble I used is just   \documentclass[12pt,a4paper]{article}  \usepackage{amsmath} \usepackage{amsthm} \usepackage{amssymb}   I don't feel it's so good because the first paragraph has no indent but the second does. If the first paragraph is much longer, than it's fine. But if not, it looks strange. Should I leave it, or you have suggestions for this?


If there is a circle in one frame(inertial and stationary),then what will the circle look like from another moving frame

Imagine a solid 3D cube. Now imagine that this cube is traveling close to the speed of light. To what degree will the spatial geometric properties of this object (or in general of any 3D object) change (as predicted by the Lorentz transformations)? I assume that despite the changes to shape, some fundamental geometric features of 3D objects are preserved no matter the frame of reference. I assume that a cube will preserve some of its fundamental geometry Namely, a cube undergoing Lorentz contraction will not become a torus or vice-versa. (I might be wrong about this) But what is the formal limit to these changes? Will the affine structure of a 3D object undergoing Lorentz contractions change or would its topology also change?


I am well aware of the analytical proofs. I was wondering if a purely geometric one was/can be found.

Is there a geometric proof for irrationality of $\pi$? That would be neat.


Let $n$ be a positve integer. Prove that$$\sum\limits^m_{k=0} \frac{2n-k\choose k}{2n-k\choose n}\frac{2n-4k+1}{2n-2k+1}2^{n-2k}=\frac{n\choose m}{2n-2m\choose n-m}2^{n-2m}$$ for each non-negative integers $m\leq n$.  I know this is to be done by induction. Base case is easy. But I can't simplify expression for $(m+1)$. Please guide.   Edit: $\large P(m+1)=P(m)+\frac{2n-(m+1)\choose m+1}{2n-(m+1)\choose n}\cdot\frac{2n-4(m+1)+1}{2n-2(m+1)+1}\cdot2^{n-2(m+1)}$  $\Large=\frac{n\choose m}{2n-2m \choose n-m}.2^{n-2m}+\frac{2n-m-1\choose m+1}{2n-m-1\choose n}\cdot\frac{2n-4m-3}{2n-2m-1}.2^{n-2m-2}$   It must be equal to $\Large\frac{n\choose m+1}{2n-2m-2\choose n-m-1}.2^{n-2m-2}$  So lets try to simplify it-   $\Large=\frac{n!(n-m)!}{m!(2n-2m)!}.2^{n-2m}+\frac{n!(n-m-1)!}{(m+1)!(2n-2m-2)!}\cdot\frac{2n-4m-3}{2n-2m-1}\cdot2^{n-2m-2}$   $\Large=\frac{2^{n-2m-2}\cdot n!(n-m-1)!}{m!(2n-2m-2)!(2n-2m-1)}[\frac{2}{1}+\frac{1}{(m+1)}\cdot\frac{2n-4m-3}1]$   $\Large=\frac{2^{n-2m-2}\cdot n!(n-m-1)!}{m!(2n-2m-2)!(2n-2m-1)}[\frac{2n-2m-1}{m+1}]$   $\Large=\frac{2^{n-2m-2}\cdot n!(n-m-1)!}{(m+1)!(2n-2m-2)!}$  $\Large=\frac{\frac{n!}{(m+1)!(n-m-1)!}}{\frac{(2n-2m-2)!}{(n-m-1)!(n-m-1)!}}\cdot2^{n-2m-2}$  $\Large=\Large\frac{n\choose m+1}{2n-2m-2\choose n-m-1}.2^{n-2m-2}$   I think it is right. But is there any shorter way also?


I'd be very grateful if someone could help me understand the idea behind link functions:  I know that the idea is that we want to map the mean to the $\eta$-vector. Also, I know that the canonical link is the one that makes $\eta=\theta$, where $\theta$ is the parameter.  But why/when do we want to choose the canonical link? When do we have to consider other alternatives?  Thanks a lot!

What's the difference between terms 'link function' and 'canonical link function'? Also, are there any (theoretical) advantages of using one over the other?  For example, a binary response variable can be modeled using many link functions such as logit, probit, etc. But, logit here is considered the "canonical" link function.


When I'm typing, accidental clicks from my touchpad are performed, like switching the line where the cursor is, or the whole window. I want to prevent this.  My current test to verify if a solution satisfies my needs is to open a terminal and press only one key over and over again and at the same time pressing a click on the touchpad. If the line/ window changes the test failed.  Solutions I tried:   syndaemon Touchpad-indicator   I currently run Ubuntu 16.04, but had the same issue on nearly all my operating systems. I also checked xinput list, and only one touchpad is recognized. My touchpad manager is SynPS/2 Synaptics TouchPad.

It's impossible to write this way, text gets deleted, windows change, random tabs open. I've tried every solution I came across but none actually solve it (some don't even work)  I've tried installing touchpad indicator, I've tried adding a syndaemon option from startup application, I tried the same but from the terminal, nothing works.  I Just want to disable the touchpad completely while typing, no scrolling, no moving the cursor, nothing.


A little back-story -- Recently I saw a question SO  (with a bounty of +50 rep) where I knew the answer. Someone had already attempted to answer the question both in comments and with an official answer, but it did not solve the OP's issue. So, I posted the correct problem, and then posted a link to a very nice blog post I found with a detailed step-by-step of how to fix it.  The first answerer then updates their answer to include the info from the blog that I posted and even credited me for finding the info, and the OP accepts their answer. After the initial disappointment, I began to genuinely question which IS the better answer, and which should be accepted. Is the better answer the one that solves the issue, or the one that is more thoroughly laid out in the answer section without extra links to external info?  Here's the real question...   What are the top three qualities/attributes of an answer?  P.S. This question is not intended to be a complaint. In fact, in the above mentioned question neither my post nor the accepted answer was IMHO "best"; it was a third answer that was best because it was more elegant and better described the problem.  Really I'm looking for a litmus test, or rule-of-thumb checklist of for weighing two or more correct answers.  The best answer here should clarify, better refine, or present what you believe are the best principles for selecting an answer.   If "best practices" don't exist for something as deceivingly simple as selecting an answer, what principles might you suggest?  (Answers backed by examples or documentation are prefered)

Lately I've been getting some good answers to some specific questions. However, I've been hesitating on what answer I should accept.  Do I go with the short quick answer or do I accept a later answer where someone has elaborated on the previous answer with some code?  It's not really important but it kind of bugs me to not accept an answer when people have taken the trouble of replying.  Here's two examples:


I only have access to the review queues on the Raspberry Pi Stack Exchange and Ask Ubuntu, but on the First Posts queue, the No Action Needed button has a grammatical issue on the tooltip.   I can't grab a screenshot right now, but on the Ask Ubuntu and RPi SE the tooltip says this answers seems to be valid and it should be, at least to be grammatically correct, This answer seems to be valid.  Just a heads up, not a huge issue, just something grammar freaks  might notice and freak out on.

If you go to the First Posts review queue, and if there's an answer in the queue and if you hover with your mouse over "No Action Needed", then you get a tooltip "this answers seems to be valid":  But it should be "this answer seems to be valid".


write the most simple algebraic proof you can, that means no integrals and no exponential generating functions if possible.  I have tried to solve it for close to 2 hours. what I got to is almost nothing but here it is : $1/2 * \mathrm{2}^{2n+1}=\mathrm{2}^{2n}=\mathrm{4}^n=\mathrm{(2+2)}^n= \sum_{k=0}^n\binom{n}{k}\mathrm{2}^k\mathrm{2}^{n-k}=?\sum_{k=0}^n {n+k \choose n}\mathrm{2}^{n-k}  $  and that's it. this is the first time I tried to use symbols so if something goes wrong, I am terribly sorry.

I just found this identity but without any proof, could you just give me an hint how I could prove it? $$2^n = \sum\limits_{k=0}^n 2^{-k} \cdot \binom{n+k}{k}$$  I know that $$2^n = \sum\limits_{k=0}^n \binom{n}{k}$$ but that didn't help me


I have the following method written that gets a substring from a string with the start and end index. For indexed that will go out of bounds, how do I write a test case in Junit? For example, if the string is banana and the method is run as getSubstring(3,12), the method will throw a out of bounds error. How do I write a test case that will pass when this error is shown?  public String getSubstring(int start, int end){         sub = MyString.str.substring(start, end);         return sub;     }    @Test public void testgetSubstring() {     MyString test = new MyString();     String result = test.getSubstring(3,12); }

How can I use JUnit4 idiomatically to test that some code throws an exception?  While I can certainly do something like this:  @Test public void testFooThrowsIndexOutOfBoundsException() {   boolean thrown = false;    try {     foo.doStuff();   } catch (IndexOutOfBoundsException e) {     thrown = true;   }    assertTrue(thrown); }   I recall that there is an annotation or an Assert.xyz or something that is far less kludgy and far more in-the-spirit of JUnit for these sorts of situations.


Working at object mapping with Java and JDBC for SQL Server I wondered myself if I would create a variable to save the value that returns a select sentence or if I could put the sentence in the foreach loop.  I have post the complete function but the question is only about the foreach loop. Both options works good for me, but I wanted to know if there is any difference about efficiency or if exists any case where the first one could fail.  public static List<User> UserList() {     BD miBD = new BD(BD_SERVER,BD_NAME);     ArrayList<User> list = new ArrayList<User>();       for(Object[] tuple: miBD.Select("SELECT name,password FROM tUser;"))     {         String id = (String)tuple[0];         String p = (String)tuple[1];         User u = new User(id,p);         list.add(u);     }      return list; }   or      List<Object[]> tupleList = miBD.Select("SELECT name,password FROM tUser;")      for(Object[] tuple: tupleList)     {         String id = (String)tuple[0];         String p = (String)tuple[1];         User u = new User(id,p);         list.add(u);     }     return lista; }   Which is more advisable to use?

Consider:  List<String> someList = new ArrayList<String>(); // add "monkey", "donkey", "skeleton key" to someList     for (String item : someList) {     System.out.println(item); }   What would the equivalent for loop look like without using the for each syntax?


I am trying to create square buffers around given points, I am able to create circular buffers but how do I create square ones?  from shapely.ops import transform from shapely.geometry import Point     local_azimuthal_projection = "+proj=aeqd +R=6371000 +units=m +lat_0={} +lon_0={}".format(lat, lon)                     wgs84_to_aeqd = partial(                         pyproj.transform,                         pyproj.Proj('+proj=longlat +datum=WGS84 +no_defs'),                         pyproj.Proj(local_azimuthal_projection),                     )                     aeqd_to_wgs84 = partial(                         pyproj.transform,                         pyproj.Proj(local_azimuthal_projection),                         pyproj.Proj('+proj=longlat +datum=WGS84 +no_defs'),                     )                      point_transformed = transform(wgs84_to_aeqd, Point(float(lon), float(lat)))                     buffer = point_transformed.buffer(0.5*1000)                     buffered_geom = transform(aeqd_to_wgs84, buffer).exterior.coords[:]

I have a large collection of points with X and Y coordinates in a projected coordinate reference system (EPSG:28992). I would like to compute a square buffer around it (say, 500 meters around the point), so I can crop this polygon with a raster layer (in TIFF format) and proceed with a further analysis with the values within the cropped windows.  I am aware that this is possible in , but for the sake of the workflow I am implementing, I prefer to have it entirely in the Python GDAL environment, so it becomes automatic. Since I know the X/Y coordinates and the size of the grid cells in the raster, I could add/subtract to the coordinates the desired buffer, but I wonder whether there is a less handcrafted version of this "square-buffer" operation, which is less prone to errors. Other Python libraries (e.g. shapely) would be fine for me as well.   Note that a band.GetRasterBand(1).ReadAsArray(X, Y, 5, 5) does not return the window around the point, but the window leaving the point in a corner.   For instance, the following code:  path_curr_lyr = r"path_to_tif_file" tif = gdal.Open(path_curr_lyr) dat = tif.GetRasterBand(1).ReadAsArray(9550, 9620, 1, 1) print(dat) sq_buf = tif.GetRasterBand(1).ReadAsArray(9550, 9620, 5, 5) print(sq_buf)   Accesses the raster grid cell X/Y (9550, 9620) and returning the value of forest coverage in that pixel, and the value of a window of width= 5 pixels.  >>> [[44]] >>> [[ 44  87  99  86  43]      [ 96  99  99  79  14]      [ 99  99  98  34   9]      [ 99  86  27  93  71]      [ 98  98 100  97  65]]    As you can see, this approach returns a window in which the "44" is not a central value, but one in the corner. I would like to have a procedure in which a window around the given grid cell coordinate is created.  Any advice on how to implement this?


After installing OS update, reboot and wifi doesn't work. Looked at similar problems, but unfortunately there was nothing to help.   $ lspci -knn | grep Net -A2 08:00.0 Network controller [0280]: Broadcom Corporation BCM43142 802.11b/g/n [14e4:4365] (rev 01)     Subsystem: Dell Wireless 1704 802.11n + BT 4.0 [1028:0016]     Kernel modules: bcma, wl   sudo systemctl restart network-manager.service doesn't help, driver is worked. property reinstalled.

This issue happens only on UEFI systems with enabled Secure Boot.  When I try to install DKMS modules like VirtualBox, Nvidia, or Broadcom drivers, they do not install and I get Required key not available when I try to modprobe them.  VirtualBox complains that vboxdrv is not loaded.  Broadcom wl driver is shown in lspci -k as a kernel module but is not in use. sudo modprobe wl throws Required key not available.  Also this issue may happen when I install some kernel modules from git sources.  This issue may appear after a kernel update as disabled wireless adapter, black screen after a reboot, etc.   How can I fix it?


I have the next file test.txt with content:  - name: MONGODB_HOST     value: {{MONGODB-HOST}}   I want to replace {{MONGODB-HOST}} with this env variable:  MONGODB_HOST=server.dev.example,server2.dev.example   Command is:  /bin/sed -i 's,{{MONGODB-HOST}},'"$(MONGODB_HOST)"',' "test.txt";   And it fails:  /bin/sed: -e expression #1, char 56: unknown option to `s'   If I leave:   MONGODB_HOST=server.dev.example   it works. Can you help me find the reason why it is failing?

I execute a sed command in my script:  sed -i "${1}s/${2}=.*/${2}=${REPLY}/" $3   this is the echo:  sed -i 13s/log4j.appender.ROOT2.File=.*/log4j.appender.ROOT2.File=/app/TET/log.log/ /applis/DIAPASON/diapason1/conf/log4j.properties   My error:  sed: -e expression n°1, character 61: unknown option fors`'


I upgraded from 16.10 to 17.04 and although wifi is detected but it is unable to connect.  I tried to remove and reinstall drivers:  sudo apt-get purge bcmwl-kernel-source sudo apt-get install linux-generic bcmwl-kernel-source   But still it doesn't work. WiFi adaptor: TP-Link WDN 4200  lsusb result:  Bus 002 Device 005: ID 0458:003a KYE Systems Corp. (Mouse Systems) NetScroll+ Mini Traveler / Genius NetScroll 120 Bus 002 Device 004: ID 04f2:0736 Chicony Electronics Co., Ltd  Bus 002 Device 003: ID 046d:c534 Logitech, Inc. Unifying Receiver Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 003: ID 148f:3573 Ralink Technology, Corp. RT3573 Wireless Adapter  Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub   Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

My Panda USB wi-fi adapter works just fine on 16.10, but when I try to connect to my wi-fi router in 17.04, GNOME network manager reports "Connection failed." I did some tinkering, and noticed that my MAC address for my wifi adapter, according to GNOME, is DIFFERENT every time I make it forget my wifi settings and try to reconnect. Any leads on a possible fix or work-around?   I'm running Ubuntu GNOME 17.04, kernel 4.10.0-19-generic, GNOME 3.24.0.


Between Dune and Dune Messiah, Paul Maud-Dib's Fremen armies swept across the galaxy in a bloody Jihad.  What I don't understand is who this Jihad was raged against.  The key Harkonnen leaders were all dead, House Atreides was aligned with House Corrino through the wedding of Paul to Irulan.  So who was it that the Jihad was raged against, and why did the Fremen commit such a bloody atrocity?  What about their religion and culture demanded such a war (as I understand it the Lisan-al-Gaib prophesy and Liet's vision for Arakkis did not necessitate galactic war)?  I am not interested in answers from the Dune movie.

How could, and why would, the Fremen's jihad kill 61-Billion people and conquer the known universe?  Their leader Paul was already emperor.  What was left to conquer?  And how could they force this onto Paul when they had no relationship with the Spacing Guild except thru Paul?  If Paul didn't arrange for transportation then how would they get off Arrakis?  And how does a small population of hardened, rugged, but not technologically advanced people do that much conquering in that time?  Also, is there any explanation about how Ix, Tleilex planet and Bene Gesserit planets hold off the wave of jihad?


How to fix “The system is running in low graphics mode” error on dell inspiron.1525?

Note: This is an attempt to create a canonical question that covers all instances of "low-graphics mode" error that occurs to a user, including but not limited to installation of wrong drivers, incorrect or invalid lightdm greeters, low disk space, incorrect installation of graphics card like ATI and Nvidia, incorrect configuration of xorg.conf file while setting up multiple monitors among others. If you are experiencing the "low-graphics mode" error when trying to login but none of the following answers work for you, please do ask a new question and then update the answers of this canonical question as and when your new question gets answered.   When I try to boot into my computer, I am getting this error:  The system is running in low-graphics mode Your screen, graphics cards, and input device settings could not be detected correctly. You will need to configure these yourself.   How do I fix the failsafe X mode and login into my computer?  Answer index:


My new visa is valid for 90 days within 12-10-2018 to 12-10-2019. My last visit ended on 30-07-2018 and I plan to enter again at 23-10-2018. Will border control in the Netherlands deny entry because of the 180 days rule, even if the visa is valid?   The linked answer explains about the base of the rule. To rephrase my question: Will border control check the last stay or will they allow entry based on the visa validity?  Both the last stay and the intended stay are 90 days.

I have searched the web a lot and could not find an answer that fits my situation. Here are two links that are quite contradictory:       My situation:  I've visited Portugal in December 2012 for 29 days on a Schengen visa valid from December 1st, 2012 to February 1st, 2013 for research purposes (I am a Ph.D. student). I want to visit Sweden from February 10th, 2013 to May 10th, 2013 (89 days). I have applied for a Schengen visa again (for research). How will the 90/180 rule work in my situation?


I know there are several webpages and githubs regarding Realtek wifi driver installation, but I am just not understanding it. If someone could please help me to install the driver for my device, I would appreciate it. lsusb yields: 0bda:b812 Realtek Semiconductor Corp. USB3.0 802.11ac 1200M Adapter So I found this Github, but I don't know how to use it:  I downloaded the .zip, extracted it, opened a terminal and typed "sudo make," but the script seems to have errors running throughout it. I think I am missing some kind of argument at the start, but I'm not sure. The end of the script is: cc1: all warnings being treated as errors make[2]: *** [scripts/Makefile.build:275: /home/[user]/Downloads/rtl88x2BU_WiFi_linux_v5.2.4.4_26334.20180126_COEX20171012-5044-master/os_dep/osdep_service.o] Error 1 make[1]: *** [Makefile:1757: /home/[user]/Downloads/rtl88x2BU_WiFi_linux_v5.2.4.4_26334.20180126_COEX20171012-5044-master] Error 2 make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-51-generic' make: *** [Makefile:1795: modules] Error 2  If I run "sudo make install" after this, I receive: install -p -m 644 88x2bu.ko  /lib/modules/5.4.0-51-generic/kernel/drivers/net/wireless/ install: cannot stat '88x2bu.ko': No such file or directory make: *** [Makefile:1801: install] Error 1  Am I even on the right track? Is this what I'm supposed to do with the download from gitHub? Is it supposed to work automatically after a reboot (if the script runs correctly)? If somebody could please help me out, I would appreciate it.

So I've been experimenting with Ubuntu on and off for a while, but I honestly have no idea what the hell I'm doing. So I have a realtek RTL8812bu WiFi dongle that I'm hoping to get working. I did some research, and came across  that a couple people across two threads said worked for them:  At the bottom it said there is a new version . So somewhere it said it was confirmed to work on kernels up to 4.16, so I checked and I'm on 4.15.0. But the problem I'm having, is what am I supposed to do? There is some installation guide at the bottom that is about as clear as mud to me since I don't know much.


If you select a cell in Excel containing text or a numeric value and copy to clipboard, then paste into an application like Notepad or Word, it always pastes a line-break.      If you double-click the cell and select-all the contents in edit mode, you can copy-paste this but thats quite cumbersome as you now can't use only the keyboard, and it adds extra clicks.  I wondered if there might be a special keyboard shortcut to copy as if I was editing the cell contents?

When I copy text from a cell in Excel and paste into a text document a line break is appended.  Example:  Some Link   CTRL-C/CTRL-V  Some Link   Is it possible to copy as plain text without additional line breaks added?


Imagine a trivial circuit with battery and one resistor. To measure the "voltage drop" across the resistor, we stick a voltmeter in parallel with it. However, this means the voltmeter is also directly electrically connected to the terminals of the battery. Therefore, why doesn't it simply measure the battery voltage, regardless of the resistor?        I hypothesized that the answer is because some of the available voltage/pressure/force/power/energy/magic/whatever-it-is from the battery is being drained through the resistor, it will not be passing through the voltmeter and will therefore not be measured by it, but this still doesn't fit, because that means the voltmeter is not measuring the voltage drop; it's measuring the voltage that wasn't dropped. If the battery supplies 5 V and voltmeter reads 4 V, how is 4 V possibly the voltage drop of the resistor, when the available voltage has actually dropped by 1 V and I still seem to have a non-dropped 4 V to play with?  I guess I really do not understand what the voltage drop is supposed to mean. I don't know why the resistor is dropping voltage at all, when it is supposed to resist current. I'm so lost.

I am taking my first steps into learning about electronics as a hobbyist and I am struggling to understand something about resistance.  I have read about Ohm's law and it seems fairly straightforward so I set up a simple circuit on .    This circuit consists of a 9V battery and a single resistor (10 Ohms) with its leads connect directly to the 9V battery.          – Schematic created using   When I place the probes of their simulated voltmeter across the leads of the resistor, it reads 7.83V.  I can't make any permutation of Ohm's law produce that result.  What would be the expected voltage across the resistor?  Based on other posts on this site, I would expect the voltage to be 9V.  I don't know how that simulator (123D) calculates its values or how it simulates the circuit.  I am sure that I am missing something fundamental but so far I haven't figured out what.  Is the 123D circuit simulator right?  Should there be only 7.83V across that resistor?  I set up a similar circuit (using CircuitLab) and it seemed to show that the voltage would be 9V.  So I am confused.  Is this just an inaccuracy of the 123D's simulator?  Can someone help me to clear the fog?


I'm having trouble determining u and v using gcd algorithm, stuck on combining reverse of 308 and 273. I'm lost on what to do after laying out d=rk=... Is there a fixed order to what lines to use?  Work:  273u+308v=GCD(308,273)  a=273  b=308  d=7  273=35x7+28  308=273x1+35  35=308+(-273)x1  28=273+(-35)x7  7=35+(-28)x1  7=28x1+7  =28x1+(35+(-28)x1)  =??

I'm confused about how to do the extended algorithm. For example, here's the gcd part gcd(8000,7001)  $$\begin{align}8000 &= 7001\cdot1 + 999\\ 7001&=999\cdot 7+8\\ 999&=8\cdot 124+7\\ 8&=7\cdot 1+1\\ 7&=1\cdot 7+0\\ \gcd(8000,7001)&=1\end{align}$$    Now, the extended algorithm  $$\begin{align}1 &= 8 - 1\cdot7\\ &= 8 - 1\cdot(999 - 8\cdot124)\\ &= -1\cdot999 + 8\cdot125\end{align}$$  How do you get this 8*125 from the previous line?


I would like to have a new option in the \includegraphicscommand. The idea ist that there is no error when the file does not exist - maybe just a friendly warning.   Ideally, the file extension is not needed (to be flexible in the future) but if it's needed that's also ok (at the moment it's not necessary).  \documentclass[a4paper,11pt]{article}  \usepackage{graphicx}  \begin{document}  \includegraphics[myDoNotComplainIfFileIsMissing]{MyFileThatMayOrMayNotExist.ext}  \end{document}   Possible duplicates

I was recently in charge of organizing all of the references and labels in a very large scientific proposal document.  My workflow typically involved compiling the document, seeing a "There were undefined references." statement, and then searching the resultant PDF file for the usual "?" or "??."  Sometimes those missing references were in regard to labels for figures that were used throughout the text and not something in our bibliography.  It got me wondering:   Is it possible to have a "dummy" or "default" figure to use in \includegraphics statements if the requested file is missing?  Perhaps a use case would be if in the LaTeX document there were a command such as \includegraphics{scaling.pdf}, but scaling.pdf doesn't exist in the current directory, so we use the existing dummy.pdf automatically.  I assume this involves renewcommand'ing the includegraphics command, but how should one go about doing  it for this scenario?


I have a large document that contains many different chapters which reference each other. The body of the main latex file looks something like:  \maketitle \tableofcontents  \include{chapter1} \include{chapter2} ... \include{chapter10}   I wish to create several documents that only contain selected chapters (i.e. chapters 3 and 8). These chapters should be numbered the same as they are in the main document so the nice latex auto-numbering is less than helpful in this case. I know I can use \setcounterdepth to make sure the chapters are numbered as I wish so that's not a problem. However, once I am no longer including a chapter, latex doesn't know where to point the reference to.   Is there any solution where the compiler looks at all of the files but only actually includes some in the compiled document?   I also want only the included chapters to be in the TOC. Not sure if that would complicate the problem at hand.

My document structure has   one file with preamble (i.e. MainTex) and around 75 individual .tex files (i.e. Chapter_01, Chapter_02, ..., Chapter_75) representing each chapter.   I am using \include command to create a one big PDF file, the output is MainTex.pdf. Life is all good up to this point.   If I have to create individual PDF for each chapter then do I need to run 75 times with each chapter name and rename the PDF manually to match to chapter name. Because if I include only Chapter_01 and run it creates PDF named as MainTex.pdf.  Is there a way I can automate this workflow?


I want to clip a MODIS image collection to an area defined by a bounding box in Google Earth Engine and then export the images separately to my google drive. I want to use a map function to avoid for loop, but the export module parameters can not be dynamically set. For example, for the description (that would be the file name), I want it to be equal to the id of each individual image. However, export module expect a string for name and can not accept a computed object. getInfo() also doesn't work in mapped functions.  var imageCol = MODIS.select('LST_Day_1km').filterDate(startDate, endDate); var clippedCol = imageCol.map(function(image){        var clipped = image.clip(Bbox);        Export.image.toAsset({        image: clipped,        description: image.metadata('system:index'),        region: Bbox,        scale: 1000     });        return clipped   });   Any clue?

I am trying to export each image in a filtered stack of Sentinel-1 images and cannot seem to get it right.   suggests using imageCollection.map() and a custom function (such as a geometric clip).  // Create a geometry representing an export region. var roi = ee.Geometry.Rectangle([-63.0, 9.2, -63.1, 9.3]);   // Load the Sentinel-1 ImageCollection. var sentinel1 = ee.ImageCollection('COPERNICUS/S1_GRD');   // Filter by metadata properties. var IW_H = sentinel1   // Filter to get images with VV and VH dual polarization.   .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'VV'))   .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'VH'))   // Filter to get images collected in interferometric wide swath mode.   .filter(ee.Filter.eq('instrumentMode', 'IW'))   // Filter IWs to get High res.   .filter(ee.Filter.eq('resolution', 'H'))   // Filter IW-Highs to get 10m res   .filter(ee.Filter.eq('resolution_meters', 10));   // Filter to get images from different look angles  var DescCollection = IW_H.filter(ee.Filter.eq('orbitProperties_pass', 'DESCENDING'));   var ClipFunc = function(iImage, geom) {   var iClip = clip(iImage, geom);   return(iClip); };   imageCollection.map(ClipFunc(DescCollection, roi));


I am not able to understand the reason, why the below code is throwing CME, even when this is run as single thread application  import java.util.ArrayList; import java.util.List;  public class ConcurrentModification {      public static void main(String[] args) {         ConcurrentModification con = new ConcurrentModification();         con.call();     }      void call() {         List<Integer> l = new ArrayList<Integer>();         for (int i = 0; i <= 10000; i++) {             l.add(i);         }              for (Integer j : l) {                 if (j % 3 == 0) {                     l.remove(j);                 }             }       } }   Reason:(after going through the answer and other links)     You are not permitted to mutate a list while you are iterating over it.    Only Iterator remove's method can be used to delete element from list   For Each loop is using iterator beneath it   but l.remove(j) is not using that iterator, which causes the exception

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


i have this case   $var = 'http://example.com/images/image_1.jpg'; $var_2 = 'data:image/png;base64,BASE64_DATA_HERE'; $var_3 = 'data:image/gif;base64,BASE64_DATA_HERE';   how can i make if condition to check if it is base64 or url, i want to check if it base64 first because if i just checked if it is url else it will be base64 it will be very bad, and take care of this "http://example.com/images/image_1.jpg?var=base64" i want to regex check the first of the var not the whole of it  BASE64_DATA_HERE is just example of the big str of base64 code  and i want a preg_match regex code to extract just the BASE64_DATA_HERE  something like  $var = 'data:image/png;base64,ZXhhbXBsZQ=='; preg_match(regex_here,$var,$matches); $code = $matches[1];

Is it possible to use a RegEx to validate, or sanitize Base64 data?  That's the simple question, but the factors that drive this question are what make it difficult.  I have a Base64 decoder that can not fully rely on the input data to follow the RFC specs.  So, the issues I face are issues like perhaps Base64 data that may not be broken up into 78 (I think it's 78, I'd have to double check the RFC, so don't ding me if the exact number is wrong) character lines, or that the lines may not end in CRLF; in that it may have only a CR, or LF, or maybe neither.  So, I've had a hell of a time parsing Base64 data formatted as such.  Due to this, examples like the following become impossible to decode reliably.  I will only display partial MIME headers for brevity.  Content-Transfer-Encoding: base64  VGhpcyBpcyBzaW1wbGUgQVNDSUkgQmFzZTY0IGZvciBTdGFja092ZXJmbG93IGV4YW1wbGUu   Ok, so parsing that is no problem, and is exactly the result we would expect.    And in 99% of the cases, using any code to at least verify that each char in the buffer is a valid base64 char, works perfectly.  But, the next example throws a wrench into the mix.  Content-Transfer-Encoding: base64  http://www.stackoverflow.com VGhpcyBpcyBzaW1wbGUgQVNDSUkgQmFzZTY0IGZvciBTdGFja092ZXJmbG93IGV4YW1wbGUu   This a version of Base64 encoding that I have seen in some viruses and other things that attempt to take advantage of some mail readers desire to parse mime at all costs, versus ones that go strictly by the book, or rather RFC; if you will.  My Base64 decoder decodes the second example to the following data stream.  And keep in mind here, the original stream is all ASCII data!  [0x]86DB69FFFC30C2CB5A724A2F7AB7E5A307289951A1A5CC81A5CC81CDA5B5C1B19481054D0D 2524810985CD94D8D08199BDC8814DD1858DAD3DD995C999B1BDDC8195E1B585C1B194B8   Anyone have a good way to solve both problems at once?  I'm not sure it's even possible, outside of doing two transforms on the data with different rules applied, and comparing the results.  However if you took that approach, which output do you trust?  It seems that ASCII heuristics is about the best solution, but how much more code, execution time, and complexity would that add to something as complicated as a virus scanner, which this code is actually involved in?  How would you train the heuristics engine to learn what is acceptable Base64, and what isn't?    UPDATE:  Do to the number of views this question continues to get, I've decided to post the simple RegEx that I've been using in a C# application for 3 years now, with hundreds of thousands of transactions.  Honestly, I like the answer given by  the best, which is why I picked it as the selected answer.  But to anyone using C#, and looking for a very quick way to at least detect whether a string, or byte[] contains valid Base64 data or not, I've found the following to work very well for me.  [^-A-Za-z0-9+/=]|=[^=]|={3,}$   And yes, this is just for a STRING of Base64 data, NOT a properly formatted  message.  So, if you are dealing with data of this type, please take that into account before attempting to use the above RegEx.  If you are dealing with Base16, Base32, Radix or even Base64 for other purposes (URLs, file names, XML Encoding, etc.), then it is highly recommend that you read  that  mentioned in his answer as you need to be well aware of the charset and terminators used by the implementation before attempting to use the suggestions in this question/answer set.


I need to know how to quickly find the Mystery Man. He's a good way to get caps but is very rare in my vault.  As in, like three times a month.   Any ways to find Mr Mystery quickly?

When ever I hear the music to indicate the Mysterious Stranger has arrived, I can never find him. It is almost like he is not in the vault.  What is a good way to catch the Mysterious Stranger? Where does he usually show up?


Is there any proper subring of $\mathbb{R}$ with field of fractions equal to $\mathbb{R}$? Can we construct that proper subring? Is it necessarily an integral domain?    Updated: Is there an example to construct the solution?

I wonder if there is an integral domain $A\subseteq \mathbb{R}$ which is not a field, and such that the field of fractions of $A$ is equal to $\mathbb{R}$?  Edit: here as a possible direction: it is known that there is no finite field extension $k\subseteq \mathbb{R}$. Given such an $A$, can we produce such a $k$, contradicting this theorem?


I'm running a command-line backup tool (duplicity) as a cron job. But in Mojave, there is a new user data protection feature called "Full Disk Access" (part of the TCC access control framework) that prevents duplicity from accessing certain user-owned files.  How do I whitelist this command-line tool? Since it runs as a cron job, adding Terminal.app to the whitelist won't work. I tried adding the duplicity binary to the whitelist in System Preferences > Security & Privacy > Full Disk Access, but that changed nothing. I also tried running duplicity manually to see if anything would show up in that whitelist, but nothing did.  Edit: the answer to  is not a solution. I clearly explained that I have already tried whitelisting to no avail.

As well as many of the other features talked about during macOS Mojave's release like dark mode and the addition of new apps like Home, another key feature of macOS Mojave seems to be it's heightened focus on both privacy and security.   As quoted under the "Camera and Microphone Now Require Your Permission" section of  article:      Apple also announced that other categories of data, such as your Messages history and Mail database, will be protected in a similar manner to macOS Mojave's new camera and microphone permissions.   I understand that after the update, when an app requests to use your camera or microphone, you will receive an alert like the one below:    However, I am more intrigued by the following:     ...other categories of data, such as your Messages history and Mail database, will be protected in a similar manner...   I have been unable to find much information about this online and I do not currently have the pre-release version of macOS Mojave installed and am therefore unable to test this new feature but I am curious to know what exactly this feature will mean.   Has Apple publicly documented how this will work?


If you put some tags inside the search field you will get the questions which include those tags. However, I want to search the questions which include those tags or just one of those tags. How can achieve it?

Is there a way to search questions that are tagged with either tag1 or tag2?  Actually, I would like the general filter,      ([tag1] AND [tag2], ...) OR ([tag3]   AND [tag4], ...) OR ...   And even     [tag1] AND ([tag2] OR [tag3])   I need that because I'm looking for interesting questions and I have to search for each tag separately.


[preface, i'll use '%' as the modulo or remainder operator, as it is in C and many other programming languages, where for example 10 % 7 == 3] i'm looking for an algorithm to solve for n in (A*n + B) % C == 0  where A, B, and C are all positive integers. i have additional constraints on my particular problem that i don't think are important for the solution.  (namely, A is less than C, A is a power of 3, C is a power of 2, and B is odd, all of which i believe imply that n must be odd.) (and yes, i'm toying with Collatz here) i can brute force this (try all possible n from 0 to C-1), but that will become time consuming as C increases.  i could also try to binary search for it, which would be a performance improvement, but i'm looking for a more efficient algorithm.

I know how to compute modular multiplicative inverses for co-prime variables $a$ and $b$, but is there an efficient method for computing variable $x$ where $x < b$ and $a$ and $b$ are not co-prime, given variables $a$, $b$ and $c$, as described by the equation below?   $ a x \equiv c \mod b $   For example, given  $ 154x \equiv 14 \mod 182 $, is there an efficient method for computing all the possibilities of $x$, without pure bruteforce?  Please note that I'm not necessarily asking for a direct solution, just a more optimized one.    I do not believe that the Extended Euclidean Algorithm will work here, because $a$ and $b$ are not co-prime.   Edit:  Follow up question, since the first one had a shortcut:  Could the be computed efficiently as well?  $12260x \equiv 24560 \mod 24755$.  $107$ needs to be one of the computed answers.


When I click on the "moderator tab" at the user page on , I get an empty list. This is not the case on other SE-sites (I have tried Biology SE, Stack Overflow and Academia SE).  Screenshot:   I get the same result using both Firefox 38.0.5 and Internet Explorer 11.

Post-split, Meta's moderators are (we've been told) the CMs and maybe a few other employees.  And, sure enough, those folks have diamonds.  However, something's missing:    Where are all the moderators??  Also, while I'm here, see the underlined text -- I know it's boilerplate, but since Meta doesn't have elections, you might want to change that.  (Lest you say that per-site metas have that text too, at least their associated sites have elections.  Lest you say that betas don't have elections, at least they can aspire to do so in the future.)


I just downloaded the newest iOS version, which I don't know what it is, and I can't download free apps now. I used to be able to download free apps, but now apple requires a credit card to download apps even if the apps are free.  I don't know what version of iOS I am using, nor what type I was using earlier. Nor do I know what type of iPhone I am using other than that it is an iPhone of some sort. I don't know how to find out this information either.

I  want to download free app in my iPod touch device and i have the following doubts.  Kindly resolve me doubts.   when i try to download it asks my credit card security number. since i am trying to download free app , why do i need to provide my credit card security code? Will i be debited for downloading the free app from app store?   I cant able to find any information regarding this on apple.  Please provide me some references about this from apple and please resolve my doubts.  Thanks a lot.


I have a component that I am using with a visualforce email template. It's a simple table that I get from a controller query to display Opportunity Products. I want ot format the totalprice field so instead of 10000 it shows 10,000. I found a lot of questions that suggest   <apex:outputText value="{0, Number, Currency}">   My problem is I'm not using output text because of the table part so I'm not sure where to put the value. Example:

             Product Name	             Currency Code	             Total Price
         <apex:repeat value="{!olis}" var="o">
             {!o.Product2.Name}	              {!o.CurrencyIsoCode} 	              {!o.TotalPrice}
         </apex:repeat>
   What am I doing wrong? I can save the component but no formatting takes place in the template;

is there a way to pass a string to the <apex:outputText> so that it can be formatted as a currency or percent value?  Here's what I have inside a column of my visual force table:  <apex:outputText value="{0, number, currecny}"> <apex:param value="{!row.values[1]}" /> </apex:outputText   this gives me an error at runtime (when the visual force page loads), which I think may be some kind of type mismatch, where <apex:outputText> is expecting a Decimal or number but I am passing a string.  This is the error at runtime:     The value attribute on  is not in a valid format. It must be a positive number, and of type Number, Date, Time, or Choice.   Thanks


$ sudo service ssh --full-restart  * Stopping OpenBSD Secure Shell server sshd                                                                           [ OK ]     * Starting OpenBSD Secure Shell server sshd       sshd: ../sysdeps/posix/getaddrinfo.c:2583: getaddrinfo: Assertion    `(extension ({ const struct in6_addr *__a = (const struct in6_addr *) (sin6-   >sin6_addr.__in6_u.__u6_addr32); __a->__in6_u.__u6_addr32[0] == 0 && __a->__in6_u.__u6_addr32[1] == 0 && __a->__in6_u.__u6_addr32[2] == __bswap_32 (0xffff); }))' failed.   Aborted (core dumped)

I have Windows 10 Anniversary Edition with "Bash on Ubuntu on Windows" installed and working. I'd like to be able to SSH into this Ubuntu instance, but although I have openssh-server installed and configured (and listening on port 2200), when I try to ssh to "localhost:2200", it tells me "Server unexpectedly closed network connection".  Has anyone been able to successfully accomplish this?


I'm trying something out in R and I'm curious how one would go about doing this. Let's say I have a sample of Americans and their income, furthermore I know that they are in the 90th-99th percentile of all American earners. If I assume I have that ALL income is normally distributed, how would I fit a normal distribution to the information I am given.  I have been playing around in R and using the fitdistr package and some youtube videos, however, the only examples I've seen is where fitdistr plots the entire distribution treating the input data as the whole instead only as a part if that makes sense.  So fitdistr will give me a mean and a standard deviation for my data, but in doing so it appears to be treating this small slice of earners as the entire population of Americans (obviously I'm doing something wrong) and not just as the portion falling in the 90th-99th percentile. If that makes sense?  Is there a name for what I'm trying to do beyond just fitting distributions? I'm just looking for a jumping off point or any resources that someone could point me to.  I definitely feel like this is possible, I have been playing around using different means and standard deviation levels (for instance using a mean of 50k and a std. of 25k) and then seeing how those distributions line up with the data I have but I'm just doing this visually, I'm sure there is a more rigorous way to do it in R I just don't know, I'm pretty lost because I can't get past the part to tell R that the input data is only a SLICE of the curve

My knowledge of statistics are small so I need a little bit of help.   I have some data showing the relationship between age and walking speed. The numbers of walking speed are presented only as the 15th and the 50th percentile.  For example:  Child(0-12 years): 1.07m/s (15th percentile)  1.33m/s (50th percentile).   I need to find how many percent is between 1.0m/s - 1.2m/s and 1.2m/s - 1.4 m/s etc.  That is the likelihood of observing a child walking between 1.0 and 1.2 m/s etc.   Is that possible? Please help me out.


I am struggling in this limit: $$\lim_{n\to \infty} \frac{n!}{n^n}$$ I really worked on this for few days: clearly, it goes to zero but I couln't do it rigorously. I'd really appreciate your help. Thanks from now.

I am trying to check whether or not the sequence $$a_{n} =\left\{\frac{n^n}{n!}\right\}_{n=1}^{\infty}$$ is bounded, convergent and ultimately monotonic (there exists an $N$ such that for all $n\geq N$ the sequence is monotonically increasing or decreasing). However, I'm having a lot of trouble finding a solution that sufficiently satisfies me.  My best argument so far is as follows,  $$a_{n} = \frac{n\cdot n\cdot n\cdot \ldots\cdot n}{n(n-1)(n-2)(n-3)\dots(2)(1)} = \frac{n}{n}\cdot \frac{n}{n-1}\cdot  \ldots \cdot \frac{n}2\cdot n$$  so $\lim a_{n}\rightarrow \infty$ since $n<a_{n}$ for all $n>1$. Since the sequence is divergent, it follows that the function must be ultimately monotonic.  This feels a little dubious to me, I feel like I can form a much better argument than that, or at the very least a more elegant one. I've tried to assume $\{a_{n}\}$ approaches some limit $L$ so there exists some $N$ such that  $|a_{n} - L| < \epsilon$ whenever $n>N$ and derive a contradiction, but this approach got me nowhere.  Finally, I've also tried to use the fact that $\frac{a_{n+1}}{a_n}\rightarrow e$ to help me, but I couldn't find an argument where that fact would be useful.


E:The repository 'http://ppa.launchpad.net/clipgrab-team/ppa/ubuntu cosmic Release' does not have a Release file.

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


As I understand it, the cosmological red shifting of light is one of the effects of the expansion of the universe. But as the wavelength of light increases, the momentum given by:  p = $\frac{h}{\lambda}$  decreases. I'm curious as to how this loss of momentum is accounted for.

So I have learned in class that light can get red-shifted as it travels through space. As I understand it, space itself expands and stretches out the wavelength of the light. This results in the light having a lower frequency which equates to lowering its energy.  My question is, where does the energy of the light go? Energy must go somewhere!   Does the energy the light had before go into the mechanism that's expanding the space? I'm imagining that light is being stretched out when its being red-shifted. So would this mean that the energy is still there and that it is just spread out over more space?


For example, suppose Dave always did whatever his brothers would do. He would join sport teams which his friends joined and would root for whatever team the majority of the crowd would root for. He is...?

What word or phrase best communicates the idea that a human (or other sentient being) is easily swayed, particularly between moral good and evil? Words I have found that are close are:   Impressionable - Easily influenced because of a lack of critical ability.   Implies that the subject lacks critical skills, and misses the concept of good and evil.  Gullible - Easily persuaded to believe something   Misses the concept of good and evil    I created a typical angels and demons scenario to demonstrate the polar extremes of the the spectrum. In this scenario, I lack the word to describe the humans, who can be influenced towards either end of the spectrum if impressed upon by an external entity.     The angels are devoted to good, and are immovable in their ideals. The demons are wicked, and will feign morality only to manipulate others. Both prey upon the humans, who are ____________.   I think that the key here is the spectrum of good an evil. Here are examples of other spectra and their associated words, for comparison.   Easily pushed from calm to angry: Temperamental Easily moved from determined to hopeless: Weak-willed Easily influenced by propaganda:


I updated to Ubuntu 14.04.1 and now I can't get into Grub Customizer. I am getting the following errors:  chroot '/media/grub-customizer_recovery_root_mountpoint' grub-mkconfig couldn't be executed successfully. error message:  Generating grub configuration file ... Found linux image: /boot/vmlinuz-3.13.0-34-generic Found initrd image: /boot/initrd.img-3.13.0-34-generic Found linux image: /boot/vmlinuz-3.2.0-67-generic Found initrd image: /boot/initrd.img-3.2.0-67-generic Found linux image: /boot/vmlinuz-3.0.0-32-generic Found initrd image: /boot/initrd.img-3.0.0-32-generic Found linux image: /boot/vmlinuz-2.6.38-10-generic Found initrd image: /boot/initrd.img-2.6.38-10-generic Found linux image: /boot/vmlinuz-2.6.38-7-generic Found initrd image: /boot/initrd.img-2.6.38-7-generic cat: /video.lst: No such file or directory /usr/sbin/grub-probe: error: failed to get canonical path of `'. No path or device is specified. Usage: grub-probe [OPTION...] [OPTION]... [PATH|DEVICE] Try 'grub-probe --help' or 'grub-probe --usage' for more information.   Any ideas or help?

I am trying to install Ubuntu 12.10 for quite some time, and passing hurdles one by one. Now I am in a situation as follows.  I have got a PC and 10 GB HDD which will be totally dedicated to Ubuntu so no option of Wubi and dual boot.  I was trying to install from DVD, but it is getting stuck at "Out of frequency" error. So I had to adapt for USB boot option. But my PC is USB non bootable, so workaround is "Plop Boot Manager". So I am doing the installation procedure as follows:   starting  from a CD drive which is having plop installed. opting for for USB boot in plop options. booting begins from USB. monitor eventually gives "out of frequency" error press Shift+Alt+F1 to get the terminal. open the grub with sudo nano /etc/default/grub. do necessary changes. sudo update-grub.   Now here I am getting error as follows:   /usr/sbin/grub-probe:error:failed to get canonical path of /cow.     My system is   P4 3.06 GHz, 1 GB ram , 10 GB HDD without an OS, monitor CRT lg StudioWorks (7 years old). Mobo Mercury P4 266a NDMx (865 equivalent). The whole system is perfectly in working condition under XP, but it is USB non bootable, and all other devices working perfectly.  What should I do next?


I want to install dual systems through USB flash disk, win10+ubuntu16, and now win10 is ok, then I try to install ubuntu16, just like the image show, there are maybe some problem with my graphics card on ubuntu, and I have search a lot, still can not fix this prob.  my Graphics Card is 'GTX 1070'  select 'Install Ubuntu'   then I got this

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:


The book slipped from his hands and fell on the floor with loud noise, 20 eyes looked up at him and his face turned red..... Q: approximately,how many persons where at the library? •10 •20 •40

I had an exam today (Egyptian GSEC english exam) and in a passage about library it said:     The book slipped from his hands and fell on the floor with loud noise, 20 eyes looked at him and his face turned red.....   It then asked: approximately,how many persons where at the library?  Ten or twenty or forty  But I would like to know if twenty eyes represent 10 persons or is it like a metaphor and represents 20 persons?  Is this expression even correct?  Edit : in the passage it was obvious that it is a normal library with normal people i just cut a part out of its context that serves the question


What i have done is very small. $$f'(x)=f(f(x))\implies f(f'(x))=f(f(f(x)))$$Now $$f(f(f(x)))=f'(f(x))$$Hence$$f(f'(x))=f'(f(x))$$Now i am blank. What to do for the proof

There was this question on one of the whiteboards at my company, and I found it intriguing. Maybe it's a dumb thing to ask. Maybe there is a simple answer that I couldn't see. Anyway, here it is:   Does there exist a non-trivial, monotonically increasing function such that $f'(x) = f(f(x))$ (in $\mathbb{R}$)?   I checked a bunch of functions, from elementary to special (gamma, digamma, zeta, Riemann, Lambert ...) and none seems to work (not surprisingly). I managed to convince myself that a function expressible as a power series would not work, regardless of convergence issues, because the derivative lowers the degree of polynomials, when the composition raises it. The Dirac delta or some sort of generalized function looked promising for a while, but the Dirac delta is not monotonically increasing anyway, and I'm not very familiar with generalized functions. I tried to use the Fourier transform on both sides, but it seems the Fourier transform is difficult for f(f(x)) (at least for me). I thought about somehow seeing "taking the derivative" as a differential operator, finding its (infinite) matrix in some basis (which one?), do the same thing to the RHS and show that the 2 matrices could not be identified (reducing the problem to a linear algebra problem) - that didn't work. Nothing on the geometric front either. I thought about trying to prove that there is no such function by deducing a contradiction, but didn't manage that. My hunch is that no such function exists, based on the completely invalid and semi-meaningless idea that differentiation pulls f in one direction, and composition in the other. Any idea?


I was doing the following problem:  $f$ is an analytic function defined in a neighborhood of $0$, and $f'(0)\neq 0$. Show that  $$\frac{1}{f'(0)}=\frac{1}{2\pi i}\int_{|z|=r}\frac{1}{f(z)-f(0)}dz,$$ provided that $r>0$ is sufficiently small.  I was trying to use the Cauchy integral formula for the inverse of $f$, but it doesn't seem to give the desired integral. Any help would be appreciated.

Let $f$ be analytic on an open set $U$, let $a \in U$, and $f'(a)\neq 0$.  Show that  \begin{align*} \frac{1}{f'(a)} = \frac{1}{2\pi i} \int_C \frac{1}{f(z)-f(a)} dz \end{align*} where $C$ is a small circle centered at a.  I thought that this is very similar with Cauchy's integral formula. But, I can't apply the Cauchy's integral formula. How to apply that?   Any help is appreciated..   Thank you!


I have dual boot Ubuntu 14.04 and Win8.1. For some reason (my mistake) I have my home partition (80GB) than swap (4GB) and then 200GB of unallocated space (in that order). I want to use this free space. Can I move swap partition on the end of unallocated space and extend home partition (with-out loss of data)? Or should I just make another partition where the unallocated space is. Does the position of partitions matter or no? (Someone said to me once that swap should be at the end.)

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


I have the below folder structure in Linux env: |-- Fixed_Zip |   |-- ipython_notebooks |   |   |-- notebook editor for compute_0anXhGEj.ipynb |   |   |-- notebook editor for compute_aucScores.ipynb |   |   |-- notebook editor for compute_nG27bM3w.ipynb |   |   |-- notebook editor for compute_test_scored_scikit1.ipynb  as you can see, I have file names with spaces. How can I loop thought all the subdirectories in Fixed_Zip folder, and perform the command: jupytext --to py {file} ? One more thing, I'm doing the command from groovy file, so I guess there are some syntax to adjust. I was able to run the below in my private env and it's working: SAVEIFS=$IFS IFS=$(echo -en "\n\b") for i in `find . -name '*.ipynb' -type f`; do                 jupytext --to py "$i"             done IFS=$SAVEIFS  However, when I did the same in the groovy file: sh '''     SAVEIFS=$IFS     IFS=$(echo -en "\\n\\b")     for i in `find . -name '*.ipynb' -type f`; do         jupytext --to py "$i"     done     IFS=$SAVEIFS '''  I got the below error:     raise InconsistentPath( jupytext.paired_paths.InconsistentPath: './ipytho' is not a notebook.

This question is inspired by    I see these constructs  for file in `find . -type f -name ...`; do smth with ${file}; done   and  for dir in $(find . -type d -name ...); do smth with ${dir}; done   being used here almost on a daily basis even if some people take the time to comment on those posts explaining why this kind of stuff should be avoided... Seeing the number of such posts (and the fact that sometimes those comments are simply ignored) I thought I might as well ask a question:  Why is looping over find's output bad practice and what's the proper way to run one or more commands for each file name/path returned by find ?


I've been reading 70-200 f4 is vs 2.8 non is for days and still I don't know what to do. Ok..at the moment I do not do weddings. I do portraits (babies on up), I do photo shoots of a kid or kids running, playing, jumping in some field. I am commissioned to shoot landscape, buildings, horses, dogs (a lot of dogs) sometimes stationary, as a dog can be, or moving. I might shoot outdoor sports, not often. I have been known to shoot theater plays with just stage light available. I pretty much use a canon 24 - 105 to do all of this. I want a 70 - 200 and I really want a 2.8. I do not use a tripod as I started out a street photographer and love hand held shooting (better control) SO??????? can I get a 2.8 NON IS someone help me....Please!!!

I just picked up photography a few months ago as a hobby (not planning to go professional at all), but will be getting good gear and glass over time. Right now I have a T3i, which I'm considering upgrading to a 7D or probably a used 5d Mk II next year.  For my next lens purchase, I'm considering a 70-200 L lens, I'm just not sure which one to go for.  I'm deciding between the 70-200 2.8 L with no IS, or the 70-200 f4 L with IS.  My thinking is the following:   While I do not plan to photograph weddings or anything like that, I do plan to use the lens to take pictures of my kid on school plays over the years, so I'm guessing the 2.8 would be useful there? He's not on school yet, but I hear flash is not allowed there? How would the f4 fare in such situations? I have the 18-135 kit lens with IS...I turned off the Image Stabilization on the lens, and was able to take decent pictures handheld with not-so-fast shutter speeds (1/15, 1/20's), although I do NOT have a good pulse. Would being able to do this translate well to using the 2.8 with no IS? Most of the shooting with the 70-200 will probably be done outside..just that case of shooting plays or a concert or too.   So..what should I do? Anything I'm not considering?


I have the following object with an inner screw-like cylinder, and an outer hexagonal prism:    I am trying to close this shape up by adding faces between the screw and the hexagon, to create a nut for 3d printing, essentially. But, as you can see, there are almost a hundred vertices on the screw. Is there any way to close this shape up automatically? I don't care about the topology of the model too much, as this will be 3d printed.

Hello Blender Stack Exchange,  I am trying to fill a face between 4 surfaces. Two are straight edges and two are a curved line made up of short vertices that came from a SketchUp export.  The problem: I select the vertices on the top and bottom and fill the hole. It creates a strange face that ruins the curve. I would prefer it create some sort of complex curve. I want it to be smooth.  Images attached to better explain.