I found that if I don't place \label in a \begin{figure}...\end{figure} correctly, it will generate a ?? when I \autoref it. Where is the appropriate position? \begin{figure} \label{} \includegraphics{} \caption{} \end{figure}  or \begin{figure} \includegraphics{} \label{} \caption{} \end{figure}  or \begin{figure} \includegraphics{} \caption{} \label{} \end{figure}
\documentclass{article} \usepackage{algorithm}  \begin{document} \setcounter{section}{54} \section{A section with no label} \begin{algorithm} \label{myalg} \caption{An algorithm with the label `myalg'.} \end{algorithm} Reference to myalg: \ref{myalg}. \end{document}   With this code, the reference givens 55 (the section number); if I move the label after the caption command, I get the correct reference (1).  Why should this be the case? I find it confusing: when thinking about an algorithm as an environment, you expect to be able to label it right after you began it. At the very least I would expect some kind of error or "??" to appear, rather than the previous environment or reference-able entity being used.
Windows Media Player 12 shows wrong cover art when playing How to check who owns the Slack's workspace? I'd like to check who owns (or at least some kind of public profile page) some workspace based on its subdomain (e.g. xyz.slack.com).  Is it possible? How do I invoke a Java method when given the method name as a string? If I have two variables:  Object obj; String methodName = "getName";   Without knowing the class of obj, how can I call the method identified by methodName on it?  The method being called has no parameters, and a String return value. It's a getter for a Java bean. My cat sat on my laptop and now if I type either L or P, it inputs 3 or * instead. The rest of my keyboard still works correctly. The problem is bad enough that I had to use the touch screen of my computer to type this in.  How can I restore the correct working behaviour of my keyboard? Example of a function such that $\varphi\left(\frac{x+y}{2}\right)\leq \frac{\varphi(x)+\varphi(y)}{2}$ but $\varphi$ is not convex Currently, this site embeds YouTube videos as Flash. (see an example: )  However, this is not the best solution, as now YouTube also supports HTML5, and some users (like me!) prefer to use HTML5 player instead of Flash. Supposedly, it should also work on devices that don't have Flash player (I can't confirm because I don't have one).  The solution seems quite simple: just change the embed code to an iframe, as described at     EDIT:  says:     Note: YouTube &lt;object&gt; embeds were  on January 27, 2015. Please migrate your applications to the , which can intelligently use whichever embedded player – HTML (&lt;video&gt;) or Flash (&lt;object&gt;) – the client supports. How to convert a number to words in MS Excel Android app? Excel Macros are unsupported in Android and there is also no SpellNum Function in Android . I want a function which can convert a number to words. Is there any way we can achieve this ? eg -  40004  , should be converted to Forty Thousand Four Difference between char *str="STRING" and char str[] = "STRING"? Having line color vary with data index for line graph in matplotlib? Invalid Data Source when importing geojson to QGIS Im trying to import geojson, I add data, select protocol and use the uri  QGIS says "Invalid Data Source:  is not a valid or recognized data source"  I've followed the tutorial here  but I cant get the data to come in, any ideas? I'm using QGIS version 2.18.13 How to import all files of a folder at once? Why does a bigger sensor lead to a shallower depth of field? It has been mentioned at    that a larger sensor results in images with a shallower depth of field. Example image:          I understand how sensor size would relate to, for example, field of view, but the relationship with depth of field does not seem straightforward.  It actually seems contradictory - I have more wells on my sensor, and I am able to focus on less number of points.  What is the reason for this effect? I know that python has a len() function that is used to determine the size of a string, but I was wondering why it's not a method of the string object.  Update  Ok, I realized I was embarrassingly mistaken. __len__() is actually a method of a string object. It just seems weird to see object oriented code in Python using the len function on string objects. Furthermore, it's also weird to see __len__ as the name instead of just len. In an ideal circuit, How can there be a current b/w points a &amp; b, when there is no potential difference and thus no electric field between a &amp; b? If there is no current, then where does current across the resistor come from, because that means no charge is coming from the battery (?). errors upgrading from 14.04 to 16.04 about Unknown Multi-Arch type for compiz, libkf5akonadisearch-bin packages I'm trying to upgrade my 14.04 machine to 16.04 using do-release-upgrade. After downloading the package lists for wily, I see the following errors:  Unknown Multi-Arch type 'no' for package 'compiz-core' Unknown Multi-Arch type 'no' for package 'compiz-gnome' Ignoring Provides line with DepCompareOp for package python-cffi-backend-api-max Ignoring Provides line with DepCompareOp for package python-cffi-backend-api-min Ignoring Provides line with DepCompareOp for package python3-cffi-backend-api-max Ignoring Provides line with DepCompareOp for package python3-cffi-backend-api-min Unknown Multi-Arch type 'no' for package 'libkf5akonadisearch-bin' Ignoring Provides line with DepCompareOp for package php-psr-http-message-implementation Ignoring Provides line with DepCompareOp for package php-psr-log-implementation Ignoring Provides line with DepCompareOp for package php-math-biginteger Unknown Multi-Arch type 'no' for package 'compiz-core' Unknown Multi-Arch type 'no' for package 'compiz-gnome' Ignoring Provides line with DepCompareOp for package python-cffi-backend-api-max Ignoring Provides line with DepCompareOp for package python-cffi-backend-api-min Ignoring Provides line with DepCompareOp for package python3-cffi-backend-api-max Ignoring Provides line with DepCompareOp for package python3-cffi-backend-api-min Unknown Multi-Arch type 'no' for package 'libkf5akonadisearch-bin' Unknown Multi-Arch type 'no' for package 'compiz-core' Unknown Multi-Arch type 'no' for package 'compiz-gnome' Unknown Multi-Arch type 'no' for package 'compiz-core' Unknown Multi-Arch type 'no' for package 'compiz-gnome' You may want to run apt-get update to correct these problems   It then proceeds to abort the installation. The suggested run of apt-get update doesn't seem to do anything. Googling for the above error messages yielded others having similar problems when upgrading to other, previous releases, although I've not come across any apparent fixes. It's suggested that an apt upgrade could fix the problem, but I don't see a way to easily do that (it's up to date with the latest trusty package).  What should I do in order to upgrade directly to 16.04? Special event cards and timing How to deal with bibliography items containing long URLs? How to redirect stderr and stdout to different files and also display in terminal? I want to see the output of a command in the terminal as if there was no redirection.  Also, stderr needs to be redirected to err.log and stdout needs to be redirected to stdout.log.  It would be nice to also have the exact copy of what is shown in terminal, i.e. errors printed as and when it occurs, in a separate file: stdouterr.log. I stumbled upon  on last weekend, it introduces an integral trick that exploits . On its last page, the author, Mr. Anonymous, left several exercises without any hints, one of them is to evaluate the Gaussian integral $$ \int^\infty_0 e^{-x^2} \,dx= \frac{\sqrt{\pi}}{2} $$ using this parametrization trick. I had been evaluating it through trial and error using different paramatrizations, but no luck so far.     Here are what I have tried so far:   A first instinct would be do something like:$$ I(b) = \int^\infty_0 e^{-f(b)x^2}\,dx $$ for some permissible function $f(\cdot)$, differentiating it will lead to a simple solvable ode: $$ \frac{I'(b)}{I(b)} = -\frac{f'(b)}{2f(b)} $$ which gives: $$ I(b) = \frac{C}{\sqrt{f(b)}}. $$ However, finding this constant $C$ basically is equivalent to evaluating the original integral, we are stuck here without leaving this parametrization trick framework. A second try involves an exercise on the same page: $$ I(b) = \int^\infty_0 e^{-\frac{b^2}{x^2}-x^2}dx. $$ Taking derivative and rescaling the integral using change of variable we have: $$ I'(b) = -2I(b). $$ This gives us another impossible to solve constant $C$ in: $$ I(b) = C e^{-2b} $$ without leaving this framework yet again. The third try is trying modify Américo Tavares's answer in this : $$ I(b) = \int^\infty_0 be^{-b^2x^2}\,dx. $$ It is easy to show that: $$ I'(b) = \int^\infty_0 e^{-b^2x^2}\,dx - \int^\infty_0 2b^2 x^2 e^{-b^2x^2}\,dx = 0 $$ by an integration by parts identity: $$ \int^\infty_0 x^2 e^{- c x^2}\,dx = \frac{1}{2c}\int^\infty_0 e^{- c x^2}\,dx . $$ Then $I(b) = C$, ouch, stuck again at this constant.     Notice in that  question, Bryan Yocks's answer is somewhat similar to the idea of parametrization, however he has to introduce another parametric integration to produce a definite integral leading to $\arctan$.  Is there such a one shot parametrization trick solution like the author Anonymous claimed to be "creative parameterizations and a dose of differentiation under the integral"? Why am I allowed to turn my focusing ring beyond infinity?