I have some files named as A1.txt A2.txt ... A11.txt A12.txt, etc. I want to rename them to A0001.txt A0002.txt ... A0011.txt etc. Am I doing it right?  for file in A*.txt do mv ${file} ${file/-#.txt-/-"%5d".txt} done
I've got bunch of files with ill-formed numbering:  prefix-#.ext       | for files with number 1-9 prefix-##.ext      | for files with number 10-99 prefix-###.ext     | for files with number 100-999   Due to further processing I need all of their names to be in format: prefix-###.ext. Is there any easy way to do that?
Was the significance of Arya's Braavosi coin ever explained? Jaqen H'ghar gives Arya the iron coin, she can apparently give it to any Braavosi and say Valar Morghulis and that gets her where she needs to go, but why?    Where do these coins come from and what do they indicate to a Braavosi? How would I solve the following problem involving elementary matrices? Let $A=\begin{pmatrix}0&amp;5\\ 7&amp;4\end{pmatrix}$.      1) Write $A$ as a product of $4$ elementary matrices.      2) Write $A^{-1}$ as a product of $4$ elementary matrices.   My work. I have managed to find $A^{-1}$, which came out to be this:  \begin{pmatrix}-\frac{4}{35}&amp;\frac{1}{7}\\ \frac{1}{5}&amp;0\end{pmatrix}  However, I am struggling to figure out how I would split each of these matrices into $4$ elementary matrices. Any help? I'm making a map where I want players to be able to choose there kits/classes. The problem I'm having with it though is giving players already enchanted Tools/Armour/Weapons.  I'm not sure if you can use the /give [player] [item] [amount] because you'll have to use the whole {} thing and I'm not sure how to make enchanted Tools/Armour/Weapons using that.  Can anyone help? I am trying to solve:  $$\int_{-\infty}^{\infty}\frac{x\sin{x}}{x^2 + a^2}dx$$  and show that it equals $\pi e^{-a}$ for all $a &gt; 0$.  I translate it to its complex equivalent:  $$lim_{R \rightarrow \infty} \int_{-R}^{R}\frac{z\sin{z}}{z^2 + a^2}dz = \int_{C}\frac{z\sin{z}}{z^2 + a^2}dz - \int_{\gamma}\frac{z\sin{z}}{z^2 + a^2}dz$$  where C is a half circle with radius R, above the real axis, and $\gamma$ is only the curved (top part) of the half circle.  I've shown that $$\int_{\gamma}\frac{z\sin{z}}{z^2 + a^2}dz$$ tends to 0 as $R \rightarrow \infty$.  So now:  $$lim_{R \rightarrow \infty} \int_{-R}^{R}\frac{z\sin{z}}{z^2 + a^2}dz = \int_{C}\frac{z\sin{z}}{z^2 + a^2}dz$$  By residue theorem,   $$\int_{C}\frac{z\sin{z}}{z^2 + a^2}dz = 2\pi i \cdot res_{ai}f$$  as $ai$ is the pole of $f$ that lies above the real axis.  $$2\pi i \cdot res_{ai}f = 2\pi i \cdot lim_{z \rightarrow ai} (z-ai)\frac{z sin{z}}{z^2 + a^2}$$  By L'Hospital's rule, this is equivalent to:  $$2\pi i \cdot lim_{z \rightarrow ai} (z-ai)\frac{z^2\cos{z} + 2z\sin{z} - zai\cos{z} - ai\sin{z}}{2z} = 2\pi i \cdot \frac{\sin{ai}}{2} = \pi i \sin{ai}$$  But how is $\pi i \sin{ai}$ equivalent to $\pi e^{-a}$? Did I make a mistake? identity element of $(D_n ,\gcd)$ $X^n-Y^m$ is irreducible in $\Bbb{C}[X,Y]$ iff $\gcd(n,m)=1$ I am trying to show that $X^n-Y^m$ is irreducible in $\Bbb{C}[X,Y]$ iff $\gcd(n,m)=1$ where $n,m$ are positive integers.    I showed that if $\gcd(n,m)$ is not $1$, then $X^n-Y^m$ is reducible. How to show the other direction. Please help. Let's say we have one black hole that formed through the collapse of hydrogen gas and another that formed through the collapse of anti-hydrogen gas. What happens when they collide? Do they (1) coalesce into a single black hole or do they (2) "annihilate" into radiation?  One would expect (1) to be the case if the No Hair Theorem were to hold. So I guess what I'm really asking for is a modern understanding of this theorem and its applicability given what we know today. Why isn't sizeof for a struct equal to the sum of sizeof of each member? Why do I see a double variable initialized to some value like 21.4 as 21.399999618530273? double r = 11.631; double theta = 21.4;   In the debugger, these are shown as 11.631000000000000 and 21.399999618530273.  How can I avoid this? See a list of my top voted comments? Or another way to track progress on Pundit? Pundit  Left 10 comments with score of 5 or more   I saw a discussion question that mentioned Pundit, which that stated that , however, something like top voted comments seems to fit in with the rest of stackoverflows feature set, as well as indirectly provide a method to track progress on this badge. Should there be (or is there already) a list of my top voted comments somewhere? The Monty Hall Problem - where does our intuition fail us? We know that wizards in the Harry Potter universe are subject to regular physical harm (e.g. witness injuries from being hit by Bludgers or just colliding with things when playing Quidditch).  Therefore, it's almost a certainty that an average wizard would be vulnerable to, say, a bunch of bullets.   There may likely be spell(s) to protect from projectiles - witness Dumbledore's  deployed when Voldemort sent a bunch of glass at him during the  at the end of Harry Potter and the Order of the Phoenix (according to , possibly an unusually powerful Protego or the Silver shield).   But:   those spells obviously take effort/energy/time to cast (not everyone's Dumbledore) AND more likely than not most Death Eaters wouldn't recognize a Muggle gun for a threat (or realize what kind of threat) till too late.   So, the guns should at best allow an over-matched OotP member (e.g. Harry or Hermione) to greatly equalize the power between any regular Death Eaters and themselves, and even perhaps help against Voldemort (who can't be killed with a bullet, but, at best, would need to expend magical energy and time into conjuring a shield, and, at worst, be stopped/interrupted/driven off).  So I'm looking for an explanation - ideally in-universe, but possibly just some statement by JKR - of why the Muggle-born OotP - who are likely very much at ease AND familiar with Muggle technology and live in the late 20th century - do not use guns. Or, for that matter, ANY Muggle technology of the late 20th century? Cue Arthur C. Clarke's "indistinguishable from magic" meme.  Even if they are on some kind of idiotic moral crusade to never kill their opponents (even the Jedi aren't this dumb), given the time-frame, non-lethal weapons would have already existed, such as rubber bullets and tasers.  NOTE: Please don't offer the "if they do it, Death Eaters would start using guns as well" theory. First, Death Eaters would have used the guns if they knew how to, anyway. Second, the guns, like any "secret weapon", could be reserved for strategic battles, say the defense of Hogwarts in Deathly Hallows.    The origin of the question stems from two things.  First, Harry's fascination with all things that are different in the magical world (e.g. moving photographs), based on his knowledge of the Muggle material world, as well as the somewhat amusing cluelessness of the "Muggle artifacts" expert, Mr. Weasley, regarding Muggle items and how they work.   Basically, from the books, it's clear that the Wizarding world wouldn't know details about guns or what they are for or how they work.  The second thing is it's clear, at least initially, that wizards are afraid of Muggles finding out about them. Hence all the efforts to cloak their society (basically, do you REALLY want every Muggle gunning for you, even with Magic)? The idea of how control over the Muggle world seems to be more indirect, by Death Eaters asserting mind-control over the government. This means there's an implicit understanding by Death Eaters that they don't stand a chance against armed Muggles even given the magical disparity.  Considering Harry and Hermione's overall adaptability and inventiveness (and brains in the latter case), it's mind-boggling that the idea of fighting Death Eaters with modern technology completely slipped their mind. I mean, it's a basic part of human myth (see Steel vs. Magic themes in Conan books, or Beowulf, or heck, A Yankee in King Arthur's Court). So it's not like the idea of using technology against magic would be impossible to come up with. The question begs itself - why not? Considering the fact that Rowling generally tried to be logical and consistent in building the HP universe, I feel like there must be some in-universe explanation for this that I just didn't notice.   (in-universe answers only unless there are some authoritative out-of-universe statements that are part of canon). Why won't my follower, Serana, follow me? I told my follower (Serana) to wait. But this is different. I told her to go somewhere and wait so it will activate the enemies. Well it did and I killed them. But Serana seems to be not following me anymore. I can't tell her to follow me. And she is constantly in a squatting position. The only thing I can do is tell her to wait somewhere else to move her. And I can't part ways because I'm doing a main quest and she has to be there. Can anybody give me a tip on what to do? My Logitech G5 Laser mouse has 9 buttons but it's SetPoint software only allows 5 of them to be used as "mouse buttons" and the remaining 4 can only be assigned special windows functions (Forward, Back, Cruise Up, etc) or Keystroke Assignments.  Many of the games I play will take up to 10 "MOUSE BUTTON" inputs for in-game actions but wont recognize the remaining 4 buttons even when assigned keystroke assignments.  Is there a way to make these last 4 buttons "Generic Buttons" as well as buttons 3,4,and 5? (1 is left click and 2 is right click).  My other question is if the above is not possible, maybe I can use AutoHotkey to remap keystrokes as assigned by my SetPoint software to mouse button commands?  If so how? I am going to Nepal and probably, same as everyone, through Delhi. I was considering going overland from Delhi to Kathmandu, however I have found many posts that advise against it in favor of a flight. The following concerns are the key to the proper decision, I think.  Does the overland route offer a good scenery and cultural experience or is it  better to spend that time in Nepal?  What is the rough cost of an overland journey and how does it compare with a flight?  In case of a flight, is the Indian visa necessary? I was wondering if there was a method to alter object settings at a set point in an animation in blender.  For example, I want to make the color of an object blue for the first 20 frames, but after 20 frames I want its color to change to green. Is there any known method of doing this? I could not find anything when I searched. Unable to modify files/folders in NTFS partition How to reformulate differential equation problem as OrnsteinUhlenbeckProcess I tried to export my Geogebra graphs into tikz-code. In General it works fine, but plot x^1/3 doesn't work:  \documentclass[10pt]{article} \usepackage{pgf,tikz} \usetikzlibrary{arrows} \pagestyle{empty} \begin{document} \definecolor{ccqqqq}{rgb}{0.8,0,0} \definecolor{qqttcc}{rgb}{0,0.2,0.8} \definecolor{cqcqcq}{rgb}{0.75,0.75,0.75} \begin{tikzpicture}[line cap=round,line join=round,&gt;=triangle 45,x=1.0cm,y=1.0cm] \draw [color=cqcqcq,dash pattern=on 1pt off 1pt, xstep=1.0cm,ystep=1.0cm] (-4,-4) grid (4,4); \draw[-&gt;,color=black] (-4,0) -- (4,0); \foreach \x in {-4,-3,-2,-1,1,2,3} \draw[shift={(\x,0)},color=black] (0pt,2pt) -- (0pt,-2pt) node[below] {\footnotesize $\x$}; \draw[-&gt;,color=black] (0,-4) -- (0,4); \foreach \y in {-4,-3,-2,-1,1,2,3} \draw[shift={(0,\y)},color=black] (2pt,0pt) -- (-2pt,0pt) node[left] {\footnotesize $\y$}; \draw[color=black] (0pt,-10pt) node[right] {\footnotesize $0$}; \clip(-4,-4) rectangle (4,4); \draw[color=qqttcc, smooth,samples=100,domain=-4.0:4.0] plot(\x,{(\x)*(\x)*(\x)}); \draw[color=ccqqqq, smooth,samples=100,domain=-4.0:4.0] plot(\x,{((\x))^(1/(3))}); \draw [color=qqttcc](2.06,4.18) node[anchor=north west] {$f(x)=x^3$}; \draw [color=ccqqqq](2.06,1.18) node[anchor=north west] {$f(x)=\sqrt[3]{x}$}; \begin{scriptsize} \draw[color=qqttcc] (-1.74,-7.16) node {$f$}; \end{scriptsize} \end{tikzpicture} \end{document}      Error line 21: !Missing number, treated as zero.   So plot has problems with the negative x I suppose, but I don't know. Any help would be great! I googled it for nearly 1 hour - but no real answers.  As suggestet it rotated and mirrored the graph - works great!:  \documentclass[10pt]{article} \usepackage[utf8]{inputenc} \usepackage{pgf,tikz} \usetikzlibrary{arrows} \pagestyle{empty} \begin{document} \definecolor{ccqqqq}{rgb}{0.8,0,0} \definecolor{qqttcc}{rgb}{0,0.2,0.8} \definecolor{cqcqcq}{rgb}{0.75,0.75,0.75} \begin{tikzpicture}[line cap=round,line join=round,&gt;=triangle 45,x=1.0cm,y=1.0cm] \draw [color=cqcqcq,dash pattern=on 1pt off 1pt, xstep=1.0cm,ystep=1.0cm] (-4,-4) grid (4,4); \draw[-&gt;,color=black] (-4,0) -- (4,0); \foreach \x in {-4,-3,-2,-1,1,2,3} \draw[shift={(\x,0)},color=black] (0pt,2pt) -- (0pt,-2pt) node[below] {\footnotesize \x}; \draw[-&gt;,color=black] (0,-4) -- (0,4); \foreach \y in {-4,-3,-2,-1,1,2,3} \draw[shift={(0,\y)},color=black] (2pt,0pt) -- (-2pt,0pt) node[left] {\footnotesize \y}; \draw[color=black] (0pt,-10pt) node[right] {\footnotesize 0}; \clip(-4,-4) rectangle (4,4); \draw[color=qqttcc, smooth,samples=100,domain=-4.0:4.0] plot(\x,{(\x)*(\x)*(\x)}); \begin{scope}[yscale=-1,xscale=1] \draw[rotate=90, color=ccqqqq, smooth,samples=100,domain=-4.0:4.0] plot(\x,{(\x)*(\x)*(\x)}); \end{scope} \draw [color=qqttcc](2.06,4.00) node[anchor=north west] {$f(x)=x^3$}; \draw [color=ccqqqq](2.06,1.00) node[anchor=north west] {$f(x)=\sqrt[3]{x}$}; \begin{scriptsize} \draw[color=qqttcc] (-1.74,-7.16) node {f}; \end{scriptsize} \end{tikzpicture} \end{document} Simulating group_concat MySQL function in Microsoft SQL Server 2005? I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).  In the original app, we used almost entirely ANSI-SQL compliant statements, with one significant exception -- we used MySQL's group_concat function fairly frequently.  group_concat, by the way, does this: given a table of, say, employee names and projects...  SELECT empName, projID FROM project_members;   returns:  ANDY   |  A100 ANDY   |  B391 ANDY   |  X010 TOM    |  A100 TOM    |  A510   ... and here's what you get with group_concat:  SELECT      empName, group_concat(projID SEPARATOR ' / ')  FROM      project_members  GROUP BY      empName;   returns:  ANDY   |  A100 / B391 / X010 TOM    |  A100 / A510   So what I'd like to know is: Is it possible to write, say, a user-defined function in SQL Server which emulates the functionality of group_concat?   I have almost no experience using UDFs, stored procedures, or anything like that, just straight-up SQL, so please err on the side of too much explanation :)