I want to cref to a figure but somehow it  gives the chapter the figure is in instead of the figure number. The code I used is written down below:  From which it follows that the vector $\mathbf{\psi}$ has only two independent components as shown in \cref{eq:hhd.13} In \cref{fig:hhd.1} a wave propagating in the x-z plane shown, with a in-plane shearwave SV and an anti-plane shearwave SH.  \begin{equation}\label{eq:hhd.13}  \frac{\delta \psi_y}{\delta y}=-\left(\frac{\delta \psi_x}{\delta x}+\frac{\delta \psi_z}{\delta z}\right)  \end{equation}  \begin{figure}\label{fig:hhd.1}  \includegraphics[scale=3]{./Figures/PSV-SHwaves.jpg}  \caption{P-wave, vertical S-wave (SV) and horizontal S-wave (SH)}  \end{figure}   At the place where I refer to figure 5.1. (as the caption of the figure) describes, latex prints chapter 5.
\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.
Let's consider a polynomial ring of single variable. One can define them informally by saying $P(X)=\sum_{i=1}^n a_n X^n$ while $X$ is an indeterminate variable. However, since mathematics is based on first-order logic, one can only talk about something that actually exists (as a set). So as its name says, indeterminate variable is not a sentence in $ZFC$. Nevertheless, we can formally define a polynomial ring $R[X]$ as a subset of $R^\omega$ whose support is finite. ($R$ is a commutative ring with unity) Just like a single variable, I want to know what would be the formal definition of a polynomial ring of several variables. What would be a formal definition? === I have figured out a candidate. That is,  Candidate for a &quot;Definition of a polynomial ring $R[X_1,...,X_n]$&quot;. ($R$ is a commutative ring with unity) Let $R[X_1,...,X_n]$ be the set of all functions $f:\omega^n \rightarrow R$ whose support is finite. Define $(f+g)(a,b,c)=f(a,b,c)+g(a,b,c)$ and $(f•g)(a'',b'',c'')=\sum_{a+a'=a''} f(a,b,c)•g(a',b',c')$ (Note that in this way, $+,•$ are well defined.) Then, it can be checked that $(R[X_1,...,X_n],+,•)$ is a ring.  Is this a formal definition of a polynomial ring? Links in newsletter preview link to YouTube The problem: The links at the bottom of the Stack&nbsp;Exchange newsletter link to a YouTube video instead of the right place on the website. I´m not sure if this is an oversight or a clever hack.  Screenshot: $2 \otimes_{R} 2 + x \otimes_{R} x$ is not a simple tensor in $I \otimes_R I$ Boxplot interpretation: is it correct that a boxplot is missing a whisker? Executing .bat file Is there a quick way to set an HTML text input (&lt;input type=text /&gt;) to only allow numeric keystrokes (plus '.')? Disabling middle mouse button I have some simple python code that searches files for a string e.g. path=c:\path, where the c:\path part may vary. The current code is:  def find_path(i_file):     lines = open(i_file).readlines()     for line in lines:         if line.startswith("Path="):             return # what to do here in order to get line content after "Path=" ?   What is a simple way to get the text after Path=? Community isn't on ~15 sites! Add new user and add meta at once I have been running Ubuntu 18.04 for a couple of weeks. I upgraded from 16.04 and all went smoothly.   I am not sure what I changed, but this morning I noticed that the "Settings" Icon that launches gnome-control-center is missing from "Show Applications" and the applications menu as well. When I searched from "Show Applications" for gnome-control-center or just settings, nothing showed up.   So, I figured I must have accidentally removed it and figured a reinstall of the package would resolve the issue. I have searched and found several postings where this worked. I tried:  sudo apt install gnome-control-center   And then rebooted - which reinstalled the gnome-control-center and I could then launch it from the command line. However, there was still no Settings Icon in any of the menus.   I also tried many other suggestions including:  sudo apt-get install --reinstall gnome-control-center sudo apt-get install ubuntu-desktop sudo apt install ubuntu-desktop --reinstall sudo apt-get install unity-control-center   However, none of these has been successful in restoring the icon into "Show Applications" or any applications menu.   Anyone have any suggestions on something I haven't tried? Would be much appreciated.  Or, is there a way to just manually recreate the icon?   Output of locate gnome-control-center.desktop:  /usr/share/applications/gnome-control-center.desktop  /home/dccrens/.local/share/applications/gnome-control-center.desktop /home/dccrens/.gnome/apps/gnome-control-center.desktop   I am running Ubuntu 18.04 desktop on kernel 4.15.0-45-generic. How to install Anaconda on Ubuntu? How to install  on Ubuntu?   Is there a way to use apt-get install?   I only have command line access to my server. How do I install Anaconda on Ubuntu 14.04 from the command line? indentation of a whole paragraph My problem is that I would like to write something like in LaTeX:   But I can't seem to do it wihtout reading like:   Which is pretty anoying to do all the time, in the middle of writting. Is there a code to do it for a whole paragraph without written \hspace*{1,5 cm} in middle of a sentence Area 51 reputation changes do not show up in the new Top Bar Given a Möbius transformation that maps one pair of concentric circles to another pair of concentric circles, why is the ratio of the radii preserved through the map?   I thought about how Möbius transformations are compositions of rotations, scaling, inversion, and translation, and that intuitively, these types of maps shouldn't change the ratio of radii between two circles.   Would it be correct to just say that if $\frac{r_1}{r_2}$ is the ratio of radii between the two circles, then   1) The radii are invariant under translation, $z \mapsto z+a$, so $\frac{r_1}{r_2}$ stays the same  2) Under scaling by a factor $z \mapsto az$, $\frac{ar_1}{ar_2} = \frac{r_1}{r_2}$   3) Under inversion, $z \mapsto \frac{1}{z}$, $\frac{1/r_1}{1/r_2} = \frac{r_2}{r_1}$  Or is there a different/better way to think about this problem? What's the full-form & significance of USS & ISS prefixes in name of Star Trek starships? In the Star Trek normal universe, almost all of Starfleet's starships were named with the prefix USS: Count from . Some popular ones: USS Enterprise - series, USS Stargazer, USS Exeter, USS Defiant, USS Excelsior, USS Voyager, USS Titan, USS Reliant, USS Equinox, USS Grissom, USS Relativity, etc.  In the mirror universe, Starfleet's starships were named with the prefix ISS. We don't have a big list, but we do see these: ISS Enterprise NX-01, ISS Enterprise NCC-1701, ISS Avenger.  What's the full form of USS &amp; ISS in Star Trek canon?  In the real world, the US Navy uses USS in ship names, which is reasonable as "United States Ship", but why is it used in Star Trek canon (in which there's no US to control starships)?  In the mirror universe, USS is replaced with ISS. Why? Does ISS have a meaning opposite from that of USS? Let $d=GCD(n^2+5,n^3-5n^2+6n)$ show that $d|630$ Creating files in C++ How does finder sort folders when they contain digits and characters? Understanding DC-DC boost converters I’m currently working on a solar powered boat with a modest sized team of people. For our competition we are only allowed to have 3 12v batteries on board but we are allowed to have up to 52v at any point in our setup. We are hoping to kick up the speed of our outboard motor for the sprint portion of the completion and are looking into using a boost converter for this.   After doing a little research I’m a bit confused about how they fundamentally work. From what I can tell they take in a voltage and current and put out a higher voltage with a lower current with some level of efficiency. But it seems to be independent from the load( in this case the motor) which doesn’t make much sense to me because I thought the current would be determined by whatever my load is. How do loads actually interact with boost converters?( The simpler the better.)  For reference we are using the Saietta 119r motor system and I’m considering using the MPS MPQ3425 boost converter.