Rename all the files with a specific extension in all the subdirectory
Recursively rename files and directories
Can I change my flight dates after I get my Schengen visa? Rsync, include only certain files types excluding some directories How can an ordered pair be expressed as a set? Validate decimal numbers in JavaScript - IsNumeric() What's the cleanest, most effective way to validate decimal numbers in JavaScript?  Bonus points for:   Clarity. Solution should be clean and simple. Cross-platform.   Test cases:  01. IsNumeric('-1')      =&gt; true 02. IsNumeric('-1.5')    =&gt; true 03. IsNumeric('0')       =&gt; true 04. IsNumeric('0.42')    =&gt; true 05. IsNumeric('.42')     =&gt; true 06. IsNumeric('99,999')  =&gt; false 07. IsNumeric('0x89f')   =&gt; false 08. IsNumeric('#abcdef') =&gt; false 09. IsNumeric('1.2.3')   =&gt; false 10. IsNumeric('')        =&gt; false 11. IsNumeric('blah')    =&gt; false How do they express the time, in American and British English? LaTeXiT is cropping the pdf I am using LaTeXiT (pierre chachatelier, www.chachatelier.fr) - latex equation editor for Powerpoint for mac.  It's producing pdf that appear to be "cropped" on top (see attached) - I've tried already with changing the "margins" option (Preferences>General) but unsuccessfully - don't think that's the problem.   Any hint?   Thanks Choosing colors appropriately for red-green colorblindness I want a green for "correct answer" and a red for "wrong answer". My current choice is rgb(144, 238, 144) for the green and rgb(250, 128, 114) for the red. (See wikilearner.net/wiki for the colours in action.)  I have been told that these colors are very close in contrast, making it difficult for a person with red-green color-blindness. What would be a better choice? Biometric information for a UK visitor visa for the second time I submitted my biometric information when I applied for (and successfully received) the UK visitor visa.  Now, the visa has expired and I would like to apply for it again.   Do I need to submit my biometric information again?  Will the process be the exact same as before? Markdown + Mathjax => PDF I've used LaTeX a lot in the past, but now, when comparing with StackExchange's great , I find it tedious, for short documents (&lt; 2 pages), to have to use pure LaTeX. For a short document, instead of having 30 lines as introduction: \begin{document} \documentclass[11pt,a4paper]{article} \usepackage[frenchb]{babel} \usepackage[latin1]{inputenc} \usepackage[T1]{fontenc} \usepackage{amsmath} \usepackage{amsfonts}  + &lt;lots of other things&gt; ...  I'd like to write my short document with MarkDown + Math, like on . Question: Is there an offline compiler such that compilemarkdown exercice.tex  would produce a PDF from this: #Title  Here is a *short document* including Markdown and Math, here is the equation:  $$f(x)=x^2$$  ___  Proof: ...   This is **bold**. Creating a node fitting the horizontal width of two other nodes I have the two PGF nodes foo and bar positioned in a row.  \documentclass{article} \usepackage{tikz} \usetikzlibrary{positioning} \begin{document}   \begin{tikzpicture}[node distance=0.2cm,mynode/.style={rectangle,draw}]     \node[mynode] (foo)                {foo};     \node[mynode] (bar) [right=of foo] {bar};   \end{tikzpicture} \end{document}   How can I create a third node below those two nodes with the width of foo, bar and the node distance between them? Is there a way to do this with the fit library or is this the wrong approach? Derivation of survival copula $$ \begin{align}F(x,y) &amp;= P(X\leq x, Y\leq y) \\  &amp;= C(F(x), F(y)) \end{align}$$ The copula of a bivariate distribution is equal to its CDF, $C(u,v) = F(x,y)$. The density of the data's CDF therefore can be expressed as $$f(x,y) = c(u,v) \times f_X(x) f_Y(y)$$ where $c(u,v)$ is the copula density and $f_X(x)$ is a marginal. If $\hat{C}(u,v)$ is the survival copula for determining $$ \begin{align}\bar{F}(x,y) &amp;= P(X&gt; x, Y &gt; y) \\  &amp;= \hat{C}(1-F(x), 1-F(y)) \end{align}$$ how is the first equation of the ordinary copula, $C(u,v)$, linked to the survival copula as $$\hat{C}(u,v) = u + v - 1 + C(1-u,1-v)$$ are $u$ and $v$ merely vectors containing the (ranked) observations of the uniform marginals? A derivation in integrals and probabilities (rather than $F$s) would be good. Binding single key (such as 'F1') to multiple keys (such as 'Ctrl+C') in Gnome I know how to map a single key to a command using the gconf settings. I also know how to map a single key to another key (F1 -> ctrl) using Xmodmap. My question is how can I map a single key such as F1 to a multi-key operation such at ctrl+c. I am basically trying to set up a single key to simulate copy. I can think of two ways to possibly do this:   Map single key to multiple keys so that when the single key is pressed it is essentially pressing ctrl+c. Use gconf settings to execute the copy “command” upon the single key press. I am not sure if there is a “command” to copy text. How do I get breading to stick to pre-cooked chicken for pan frying? Multivariate multiple regression validation Quotient ring of Gaussian integers Zlib-compatible compression streams? Foreword  This question was inspired by initial mistakes in . I wanted to explore the strange circle with $A&gt;\pi r^2$ and got lost into geometrical jungle.  A  is usually described by it's height $h$, radius of the base $a$ and radius of the sphere $r$. Besides we have a relation $a^2+(r-h)^2=r^2$ so the cap actually only has two degrees of freedom.  When considering a case of circle on a sphere (like the Earth), it's the surface of a spherical cap, but we can't see the height or other classic parameters of this spherical cap. Instead we encounter parameters like area $A$, perimeter $C$ and diameter $d$. I will try to write formulae for these: $$A=2\pi rh$$ $$C=2\pi a$$ $$d=2r\theta$$  Where $\theta$ is introduced with $\sin\theta=\frac{a}{r}$ or $\cos\theta=(1-\frac{h}{r})$.  As the cap only has two degrees of freedom, it should be a good problem with unique solution if only two values are known.  A-C Problem  The simple example: $A$ and $C$ are given. I show this only as example before the other tasks.  We can easily find $a=\frac{C}{2\pi}$ and then solve:  $$A=2\pi rh = 2\pi r (r-\sqrt{r^2-a^2})$$  to obtain  $$r=\frac{A}{2\sqrt{\pi(A-\pi a^2)}}$$  Parameters $a$ and $r$ are now known and it is straightforward to find $h$, $d$, $\theta$ and anything else.  C-d Problem  $C$ and $d$ are given.  First step once again is easy: $a=\frac{C}{2\pi}$. The knowing of $a$ suggests that we might prefer the $\theta$ definition with the sine. We obtain: $$d=2r\theta=2r\arcsin\frac{a}{r}$$  That's where I got stuck. Is there an easy way to solve this? Is there a hard way to solve this?  I tried solving numerically with Wolfram Mathematica and it went into complex numbers. When solving the geometrically equivalent $\sin\frac{d}{2r}=\frac{a}{r}$ I got some roots, but the search seemed very unstable and not finding the root closest to initial value. Besides it was finding a lot of different roots while I am pretty sure that there should only be one $r$ for each pair of $d$ and $a$. What would be the right formulation to solve this problem numerically?  A-d problem  $A$ and $d$ are given. This seems the hardest one. We obtain a system of equations:  $$A=2\pi r h$$ $$d=2r\arccos\left(1-\frac{h}{r}\right)$$  (The first equation suggested solving the problem in $h$ and $r$).  Is this system solvable analytically? Or numerically? My experiments with Wolfram Mathematica never converged.   Of course, I could express $h$ or $r$ from the first equation and leave only the second in one of these forms: $$d = 2r\arccos\left(1-\frac{A}{2\pi r^2}\right)$$ $$d = \frac{A}{\pi h}\arccos\left(1-\frac{2\pi h^2}{A}\right)$$  But I have no idea how to solve these either. Prove that $\prod_{k=1}^{n-1}\sin\frac{k \pi}{n} = \frac{n}{2^{n-1}}$ Using $\text{n}^{\text{th}}$ root of unity  $$\large\left(e^{\frac{2ki\pi}{n}}\right)^{n} = 1$$  Prove that   $$\prod_{k=1}^{n-1}\sin\frac{k \pi}{n} = \frac{n}{2^{n-1}}$$ I started a Roth IRA a little while ago, contributing ~$5,000, and I'd like some guidelines on how I should diversify my investments.  Should I invest in stocks or bonds or mutual funds or ETF? What percent should I contribute to these investments?  Additionally, I'm 30 years old, how might my age factor into diversification?  I understand that this is a very subjective question but any suggestions are greatly appreciated. Code for looping through all excel files in a specified folder, and pulling data from specific cells