How do I center inline-blocks?
How to horizontally center an element
Is list::size() really O(n)? Recently, I noticed some people mentioning that std::list::size() has a linear complexity. According to  , this is in fact implementation dependent as the standard doesn't say what the complexity has to be. The comment  says:     Actually, it depends on which STL you   are using. Microsoft Visual Studio V6   implements size() as {return (_Size);   } whereas gcc (at least in versions   3.3.2 and 4.1.0) do it as { return std::distance(begin(), end()); } The   first has constant speed, the second   has o(N) speed    So my guess is that for the VC++ crowd size() has constant complexity as Dinkumware probably won't have changed that fact since VC6. Am I right there? What does it look like currently in gcc? If it is really O(n), why did the developers choose to do so? I have a computer with Windows XP installed.  My user does not have a password.  When Windows starts, it goes to the login screen. Because my user has no password, is there any way to bypass this screen, and log in automatically? Cheaper alternative to parmesan cheese? The parmesan cheese in pasta recipe is quite expensive.....do we have cheaper alternative??  Are there are cheddar cheese which can replace parmesan cheese? Using different delimiters in sed commands and range addresses There is this addon that was built called Window Generator 2. It can be . However, when I go to the download link it shows up in a new tab as a bunch of code.  How can I download and use this addon in Blender? 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? I understand we cannot state with arbitrary precision the position and momentum of a micro-particle as we superpose infinite waves to create a wave packet at the exact position of the particle and hence cannot say which wave is corresponding to its momentum. This is theoretically said. Also some people say that measurement of one disturbs the other and some say it's reality.  Firstly, the theoretical explanation: why should I consider that a wave out of many superposed will give us the momentum or position? We might use another single wave which is not sine in nature and might get the results. Or why won't a single sine wave suffice? This all considers the micro-particle as wave because of de Broglie.  Secondly, the practical thing seems legit.  Thirdly, the electron must have some kinetic energy and position. It is who we are measuring and can't get it exact so why blame the electron as in theoretical concept. How we quantify the uncertainty, it must depend on the measuring device and various other factors.  I might need to edit this post based on your answer so that I can explain more clearly my thinking.  Edit: From here is what gets the measurement problem:        Text: Imagine that you're blind and over time you've developed a technique for determining how far away an object is by throwing a medicine ball at it. If you throw your medicine ball at a nearby stool, the ball will return quickly, and you'll know that it's close. If you throw the ball at something across the street from you, it'll take longer to return, and you'll know that the object is far away.   The problem i­s that when you throw a ball -- especially a heavy one like a medicine ball -- at something like a stool, the ball will knock the stool across the room and may even have enough momentum to bounce back. You can say where the stool was, but not where it is now. What's more, you could calculate the velocity of the stool after you hit it with the ball, but you have no idea what its velocity was before you hit it.   This is the problem revealed by Heisenberg's Uncertainty Principle. To know the velocity of a quark we must measure it, and to measure it, we are forced to affect it. The same goes for observing an object's position. Uncertainty about an object's position and velocity makes it difficult for a physicist to determine much about the object.   Edit: After seeing this answer one of my doubts is very well cleared, the other answers are also written and helpful:        Text: There is a definine velocity and momentum, we just don't know it.   Nope. There is no definite velocity--this was the older interpretation. The particle has all (possible) velocities at once;it is in a wavefunction, a superposition of all of these states. This can actually be verified by stuff like the double-slit experiment with one photon--we cannot explain single-photon-fringes unless we accept the fact that the photon is in "both slits at once".So, it's not a knowledge limit. The particle really has no definite position/whatever. $f:I=[\pi,2\pi]\to \mathbb{R}^2$ be given by $f(t)=(\cos t,\sin t)$  which of the following are necessarily correct?  $1$. $\exists t_0\in I$ such that $f'(t_0)=\frac{1}{\pi}(f(2\pi)-f(\pi))$  $2$. $\nexists t_0\in I$ such that $f'(t_0)=\frac{1}{\pi}(f(2\pi)-f(\pi))$  $3$.$\exists t_0\in I$ such that $\pi||f'(t_0)||\ge ||(f(2\pi)-f(\pi)||$  $4$. $f'(t)=(-\sin t,\cos t)\forall t$  $4$ is clearly true, $1$ is true by Mean Value Theorem as $f$  satisfies all the conditions of MVT? have no idea of $2$ and $3$, Thank you for help This is, how I download various master branches from GitHub, and I aim to have a prettier script (and maybe more reliable?).  wget -P ~/ https://github.com/user/repository/archive/master.zip unzip ~/master.zip mv ~/*-master ~/dir-name   Can this be shorten to one line somehow, maybe with tar and pipe?  Please address issues of downloading directly to the home directory ~/ and having a certain name for the directory (mv really needed?). How to permanently turn off online results I don't like getting online results when searching in my dashboard, so I went to System Settings &gt; Security &amp; Privacy &gt; Search, and I turned the setting off:    But when I restart my machine, the setting is always reset to:    So how can I permanently disable it without it turning on again after a restart?  Information Update:  I have had a look at the post that this has been marked as a possible duplicate of, and I don't think that my question really is a duplicate of it, as the other question is asking about how to set it globally, and I am not, I am only wanting to set it for one user, so the fact that it is not global is not the problem, the problem is that it is not sticking for that one user, and just resetting to its default state after a restart. In fact, I don't want it to be set globally, and the answers from the other question only really explain how to do that.    OS Information:  Description:    Ubuntu 15.04 Release:    15.04   Package Information:  unity:   Installed: 7.3.2+15.04.20150420-0ubuntu1   Candidate: 7.3.2+15.04.20150420-0ubuntu1   Version table:  *** 7.3.2+15.04.20150420-0ubuntu1 0         500 http://gb.archive.ubuntu.com/ubuntu/ vivid/main amd64 Packages         100 /var/lib/dpkg/status Booking travel tickets for visa without paying? I need font size = 14 in article document, but when I change  \documentclass[a4paper,11pt]{article}   to  \documentclass[a4paper,14pt]{article}   font becomes even smaller. How to change font size? How do electric currents make light? In an incandescent light bulb, electrons flow through wires to the bulb, where is passes through a filament, and the filament lights up.  Does this work because of several high energy electrons losing some of their energy to disturb the electromagnetic field, creating photons? The electrons just leave the filament afterward and are replaced by more high-energy electrons from the negative terminal. Or does it work differently?  As a secondary question, is there a type of light bulb that directly converts electron flow to photons? Cauchy-Riemann equations in polar form. Show that in polar coordinates, the Cauchy-Riemann equations take the form   $\dfrac{\partial u}{\partial r} = \dfrac{1}r \dfrac{\partial v}{\partial \theta}$ and $\dfrac{1}r \dfrac{\partial u}{\partial \theta} = −\dfrac{\partial v}{\partial r}$.      Use these equations to show that the logarithm function defined by   $\log z = \log r + i\theta$ where $z=re^{i\theta}$ with $-\pi&lt;\theta&lt;\pi$ is holomorphic in the region $r &gt; 0$ and $-\pi&lt;\theta&lt;\pi$.   What I have so far:   Cauchy-Riemann Equations: Let $f(z)$ = $u(x, y)$ +$iv(x, y)$ be a function on an open domain with continuous partial derivatives in the underlying real variables. Then f is differentiable at $z = x+iy$ if and only if $\frac{∂u}{∂ x}(x, y)$ = $\frac{∂ v}{∂ y}(x, y)$ and $\frac{∂u}{∂ y}(x, y)$ = −$\frac{∂ v}{∂ x}(x, y)$. So we have $f'(z)= \frac{∂u}{∂ x}(z) +i \frac{∂ v}{∂ x}(z)$. Let $f(z)$ = $f(re^{iθ})$= $u(r,θ)$ +$iv(r,θ)$ be a function on an open domain that does not contain zero and with continuous partial derivatives in the underlying real variables. Then f is differentiable at $z$ = $re^{iθ}$ if and only if $r \frac{∂u}{∂r}=\frac{∂ v}{∂θ}$ and $\frac{∂u}{∂θ}$ = $−r \frac{∂v}{∂ r}$.  Sorry, if this is not very good. I just decided to start learning complex analysis today... $\mathbb{Q}[x,y]/\langle x^2+y^2-1 \rangle$ is an integral domain, and its field of fractions is isomorphic to $\mathbb Q(t)$ Shut down computer from keyboard Is there a keyboard shortcut available to shutdown the computer?  I know I can use the Power button, but I would like to be able to it from the keyboard.  If such a shortcut does not exist already, how do I set one? What is the easiest way to duplicate an activerecord record? I want to make a copy of an ActiveRecord object, changing a single field in the process (in addition to the id).  What is the simplest way to accomplish this? I realize I could create a new record, and then iterate over each of the fields copying the data field-by-field - but I figured there must be an easier way to do this. Perhaps something like this:  new_record = Record.copy(:id) Find the value of $a^2-b^2+c^2$ Why is the minimum size of a generating set for a finite group at most $\log_2 n$? It seems to be known that the minimum size of a generating set for a finite group of order $n$ is at most $\log_2 n$. Can someone explain why this is true?  Edit: noted that the logarithm is base 2, and $n$ represents the order of the group. How do you document your databases? I find that most of my clients are not documenting their databases at all and I find that pretty scary. To introduce some better practice, I would like to know what tools/process people are using.   How do you document your database? (SQL-Server)  What tool do you use?  Documentation Storage Format for database schema/meta-data?   Word documents Excel spreadsheet Plain Text  Documentation process or policies?   I am not talking about reverse engineering / document a existing database, but mainly on the documentation best practices while you develop your system/database.