Data structure of list, tuple and set
Generator expressions vs. list comprehensions
$\sqrt x$ is uniformly continuous Prove that the function $\sqrt x$ is uniformly continuous on $\{x\in \mathbb{R} | x \ge 0\}$.  To show uniformly continuity I must show for a given $\epsilon &gt; 0$ there exists a $\delta&gt;0$ such that for all $x_1, x_2 \in \mathbb{R}$ we have $|x_1 - x_2| &lt; \delta$ implies that $|f(x_1) - f(x_2)|&lt; \epsilon.$  What I did was $\left|\sqrt x - \sqrt x_0\right| = \left|\frac{(\sqrt x - \sqrt x_0)(\sqrt x + \sqrt x_0)}{(\sqrt x + \sqrt x_0)}\right| = \left|\frac{x - x_0}{\sqrt x + \sqrt x_0}\right| &lt; \frac{\delta}{\sqrt x + \sqrt x_0}$   but I found some proof online that made $\delta = \epsilon^2$ where I don't understand how they got? So, in order for $\delta =\epsilon^2$ then $\sqrt x + \sqrt x_0$ must $\le$ $\epsilon$ then $\frac{\delta}{\sqrt x + \sqrt x_0} \le \frac{\delta}{\epsilon} = \epsilon$. But then why would $\epsilon \le \sqrt x + \sqrt x_0? $ Ah, I think I understand it now just by typing this out and from an earlier hint by Michael Hardy . I use the following table:  \documentclass[a4paper,              12pt,                                        bibliography=totoc,              index=totoc,             abstracton,              headsepline,             ]{scrreprt}  \usepackage{booktabs}    \begin{document}   \begin{table}[H]\hspace*{-1cm} \centering \begin{tabular}{lcclll} \toprule  Company&amp; \multicolumn{2}{c}{exceedances (empirical)}&amp;exeedances (expected)&amp;no. of obs.\\ \cmidrule(r){2-3}\\ &amp;standard normal&amp;standardized Student's-t&amp;&amp;\\ \midrule Company1&amp;1&amp;5&amp;9&amp;13\\ Company2&amp;2&amp;6&amp;10&amp;14\\ Company3&amp;3&amp;11&amp;15\\ Company4&amp;4&amp;8&amp;12&amp;16\\ \bottomrule \multicolumn{4}{l}{\begin{footnotesize}an additional hint about a detail\end{footnotesize}} \end{tabular} \caption{Here is the caption.} \label{labelhere} \end{table}   \end{document}     Which gives    I have two problems:   The space after the \cmidrule(r){2-3} is too big, how can I change this? The table looks not that good, how can I improve it in general? Several ways to prove that $\sum\limits^\infty_{n=1}\left(1-\frac1{\sqrt{n}}\right)^n$ converges Say, for example, you and a group of people were all sailing out in the ocean and something happens...then you say,  "I guess we are all in the same boat"  You are literally in the same boat with everyone else, and your current situation is the same as everyone else.  Now such a phrase can be applied literally and figuratively. I was wondering if there was a word that would mean both literally and figuratively. I know this is a tad bit of an oxymoron, but I was curious to see if there was such an "all encompassing" word for this. How to avoid spammy links affecting us before SERP rankings going down We have recently discovered a host of spammy links pointing to our website been put up in last 1 month through webmaster tool We have not engaged any seo agency/link building and have never created these links  Worst, these are spammy forum sites and almost some-one seems making an attack to our site as the link and keyword is same in all these sites Till not Have not received any warning, however as it has come to our notice - before any SERP getting down - we want to action this out  One thing we have observed is that - All these spammy links points to a single inner page of website  Pl suggest as have   a) Will Google disvow tool will work by stating to disvow these links  or  b) Is it a good way if we make this specific page 'nofollow' and even 'noindex' The reasoning behind this is like if the page is not followed and not indexed - the negative links pointing to the page of the site is already no follow and may be out from google serp  or what's the best alternate way to tackle this. Pl suggest in urgent help and advise required How should I determine whether a deck is legal in a particular format? I have a list of cards for a deck I want to build or buy. What should I do to check whether that deck is legal in a particular format (Standard, for example)? Will my software work on the next version of Windows Tracking down an old sci-fi book I'm trying to track down an old sci-fi book I read when I was a teenager.  The book was at the Cottage Grove, OR Public Library around 1982-1985.  The plot followed a brother and sister who were scientists or spies, or both.  The brother once used a series of pills to change his weight, height and appearance.  Towards the end of the book, the brother takes a space ship that his sister invented, removes a governor so that he can travel faster than the speed of light and goes back in time several hours.  This is really vague, but thanks for any leads you can share. What techniques can be used to define a class in JavaScript, and what are their trade-offs? I prefer to use OOP in large scale projects like the one I'm working on right now. I need to create several classes in JavaScript but, if I'm not mistaken, there are at least a couple of ways to go about doing that. What would be the syntax and why would it be done in that way?  I would like to avoid using third-party libraries - at least at first. Looking for other answers, I found the article  that discusses object-oriented programming in JavaScript. Is there a better way to do inheritance? How to use both binary and continuous variables together in clustering? I need to use binary variables (values 0 &amp; 1) in k-means. But k-means only works with continuous variables. I know some people still use these binary variables in k-means ignoring the fact that k-means is only designed for continuous variables. This is unacceptable to me.  Questions:     So what is the statistically / mathematically correct way of using binary variables in k-means / hierarchical clustering? How to implement the solution in SAS / R? Strange character when using listings package I'm seeing an odd character like a very flat U, where there should be a space, with the listings package. See example below. Does anyone have any idea why this is happening, or how to get rid or work around it?  \documentclass{standalone} \usepackage{underscore} \usepackage{listings} \usepackage[usenames,dvipsnames, rgb, svgnames, x11names]{xcolor} % Text layout \topmargin 0.0cm \oddsidemargin 0.5cm \evensidemargin 0.5cm \textwidth 16cm \textheight 21cm  \lstnewenvironment{cmd}[1][]{%   \lstset{language=sh, backgroundcolor=\color{LightSteelBlue1}, #1}} {}  \begin{document} \begin{cmd}[caption=Configuration file section including filters] [affy6] [...]     [[hapmap]]     phenofiles = "data/Hapmap6.0/Pheno/hapmappheno_909.csv",     genofile = "/data/snppy/Hapmap6.0/Geno/birdseed-v2.calls.txt"     anno_filter = "chromosome = 5"     idlink_filter = "studyid = 'CEU'"     some_other_stuff = "foo = bar" \end{cmd} \end{document} To show that either $R$ is a field or $R$ is a finite ring with prime number of elements and $ab = 0$ for all $a,b \in R$. A square matrix $n \times n$ is an invertible matrix iff the rank of the matrix is $n$. How does the PPA fit into the scenario of publishing an application to the Ubuntu Software Center? I've been going through docs for the past couple of hours but I haven't understood what the PPA is? I have a cross-platform Java application that I'd like to publish to the Ubuntu Software Center. My application is open-source and I'm using Github.   Apparently, publishing applications to the store isn't as simple as uploading a deb package - am I right? I need to create an account on Launchpad and put all my code there.  I don't intend to move from Git to Bzr merely for the sake of publishing to the app store but luckily, one is able to set up source-code mirroring from Github to Launchpad.  Since my application is still very premature, it'll have updates fairly often. When I build my application on my machine, do I simply go my Ubuntu App Developer page and upload the new DEB package or do they build my application from source?  What exactly is the PPA for? I don't think I'll need too many of the Launchpad features so I'd like to stick to Github if possible. Types of photon qubit encoding How many types of qubit encoding on photons exist nowadays? I know only two:   Encoding on polarization: $$ \lvert \Psi \rangle = \alpha \lvert H \rangle + \beta \lvert V \rangle $$ $$ \lvert H \rangle = \int_{-\infty}^{\infty} d\mathbf{k}\ f(\mathbf{k}) e^{-iw_k t} \hat{a}^\dagger_{H}(\mathbf{k}) \lvert 0 \rangle_\text{Vacuum} $$ $$ \lvert V \rangle = \int_{-\infty}^{\infty} d\mathbf{k}\ f(\mathbf{k}) e^{-iw_k t} \hat{a}^\dagger_{V}(\mathbf{k}) \lvert 0 \rangle_\text{Vacuum} $$ Time-bin: $$ \lvert \Psi \rangle = \alpha \lvert 0 \rangle + \beta \lvert 1 \rangle $$ $$ \lvert 0 \rangle = \int_{-\infty}^{\infty} dz\ f\left(\frac{t -z/c}{\delta t_{ph}}\right) e^{-i w_0 (t-z/c)} \hat{a}^\dagger(z) \lvert 0 \rangle_\text{Vacuum} $$ $$ \lvert 1 \rangle = \int_{-\infty}^{\infty} dz\ f\left(\frac{t -z/c+\tau}{\delta t_{ph}}\right) e^{-i w_0 (t-z/c+\tau)} \hat{a}^\dagger(z) \lvert 0 \rangle_\text{Vacuum} $$   Is there anything else? Possible Duplicate:                If in a multiple linear regression (enter method) the general model isn't significant (F>.05) but one of the predictors is significant (β&lt;.05), should I consider it as a significant result? How do we get the last day of the month from a given date Is there a function or method to give the last day of a month? For example if the date is 27 feb 2013, the last date should be 28 feb 2013 , it become 29 if its a leap year. if the date was 2 jan then it should return 31 Jan.  If there is no function then any ideas on how we can get this?  Thanks Was Quirrell the Defense against the Dark Arts teacher for more than one year? It's well seen throughout the series that there is a “curse” on the DADA teacher position, that no one can hold that post for more than a year. But it seems like Quirrell has been around for longer than a year. What's up with that? How to make child process die after parent exits? Suppose I have a process which spawns exactly one child process. Now when the parent process exits for whatever reason (normally or abnormally, by kill, ^C, assert failure or anything else) I want the child process to die. How to do that correctly?    Some similar question on stackoverflow:   (asked earlier)  (asked later)      Some similar question on stackoverflow for Windows: How are POST and GET variables handled in Python? In PHP you can just use $_POST for POST and $_GET for GET (Query string) variables. What's the equivalent in Python?