I am doing a presentation with the beamer class using the metropolis theme. Currently I am using RStudio and compile the file with XeLaTeX. Texmaker is an alternative.   - did not work for me. May be I need to compile with more than just 1x XeLaTeX?  I would prefer to use Bibtex with apacite being able to just include a .bib file for \bibliography. However, I read that there exist some conflicts?  Errors: - Rerun to get \PageLabels entry - Citation ... undefined  \documentclass{beamer} \usepackage{appendixnumberbeamer}  % various symbols \usepackage{gensymb}  % bibliographystyle \usepackage{apacite}  % Bilbliography \usepackage{filecontents} \begin{filecontents}{\jobname.bib} @Misc{Ref1,   author = {{Test author}},   title  = {Test title},   year   = {2016},   url    = {http://testurl.com=}, } \end{filecontents}  \usetheme[sectionpage = progressbar, numbering = fraction]{metropolis}   % title preface \title{Title}  \begin{document} \maketitle  % ------------------------------------------------------------------------------ \begin{frame}{Frame1}     \cite{Ref1} \end{frame}  % ------------------------------------------------------------------------------ \begin{frame}[allowframebreaks]{Bibliography}%in case more than 1 slide needed {\footnotesize \bibliographystyle{apacite} \bibliography{\jobname} } \end{frame}
Is there a 'biblatex in a nutshell' guide out there? I'd like if someone explained to me the essentials on how to use biblatex (what lines I have to write in my document, which files I have to have, how many times and what I have to compile), so then I can go to  to customise it further.
How to use classes from .jar files? I read the Java tutorials on Sun for JAR files, but I still can't find a solution for my problem. I need to use a class from a jar file called jtwitter.jar, I downloaded the file, and tried executing it (I found out yesterday that .jar files can be executed by double clicking on them) and Vista gave me an error saying "Failed to load Main-Class Manifest attribute from [path]/jtwitter.jar".  The guy who coded the .jar file wants me to import it, but where do I store the .jar file to import it in my code? I tried putting both the .jar file and my .java file in the same directory, didn't work.  The file I'm trying to work for is here:   I'm using JCreator LE. I'm asking this because my HDD (Hard Disk) has 5 years, and ultimately (this year) it gave me many headaches. Many moths ago I has Windows 7 (and 10 T.P. since april) and all was good. But after a moment, instantly, all gets reversed: veeery slow, and actions which will take a tiny time, at these moment the time seems frozen (for example, instead a 1 minute boot, it turned to 5-8 minutes boot). I formatted and installed Windows every 2 months because it was the time which runs good before it gets slooww. Seeing the abuse of privacity in W10, I changed to Ubuntu 15.04 and the things lasted more in time... But again, HDD error. Click, trying to read, click, trying to read... And the upper bar (title of window/buttons of volume, language, wifi, etc.) disappeared. The left bar (where are the app's icons) was empty and the file explorer said the resource wasn't available (or something like these error). I restarted and nothing happens. I had to press CTRL+D to boot-up Ubuntu, but after hours... the same error (can't do anything except moving the mouse/cursor).  Welcome to the routine: copy files with live-cd to a pendrive, wipe HDD and install all again. And the things was calmed again... and the errors comes again. And after 2 weeks, I had to do the same. Now my PC works fine, but yesterday I heard a few "clicks" from the HDD.  Now, I remembered this  and I came to Disks and the HDD shows a new value; normally, the problematic number was "pending sectors", always changing, but now, in "irrecoverable sectors", the number is different of zero.  I never had "reallocated sectors". Now, neither. And now, while I write this lines, I've 5 "pending s." and 9 "irrecoverable s.". If this helps, the "read error rate" is 42, 5 for "write error rate".      Very well!! While I was writing "write error rate", I heard 2   clicks. And while writing this, one click more.   And 123 "CRC error rate". So, with this information: is my HDD dying? It'll last days or months? I think this problem will kill the disk in a not very far time.  The drive is a Western Digital Green 1TB-WDC WD10EARS-00Y5B1 (80.00A80) S.N.: WD-WCAV5J301610  PS: When I boot with CTRL+D, many times the system is in "RO mode"; I can't save/download files, Unity doesn't find apps when I write their name {click again, now, while I write the text} and, after a few hours, a crash like the lines above Error Message:      "A reboot is pending. Please restart before starting Visual Studio".    I installed Visual Studio (Visual Basic 2015 and SQL 2015) and after what looked like a successful install I then got the "Reboot" window.   Not expecting it I had a bunch of things open. So I closed a bunch a bunch of things, and did the reboot myself.   Now I cannot run Visual Basic because it ONLY gives me the above error message in the pop-up window. It won't even let me do a re-install.   All it does is keep giving me the above error message.   If you have any advice that's better than a complete uninstall/reinstall I'm sure everyone in my situation would benefit from it.  How can I resolve this issue? I am new to Stack Exchange. I know there is a lot of discussion sites for Stack Exchange. I would like to know about there were any Stack Exchange site available for discussing and solving personal psychological problems. Let $T(n,x)$ be the nth Chebyshev polynomial of the first kind and let $U(n-1,x)$ the $(n-1)$th Chebyshev polynomial of the second kind. Would any one kindly help show that   1) $n$ is prime iff $T(n,x)$ is irreducible in $\mathbb{Z}[x]$.  2) $n$ is prime iff $U(n-1,x)$, expressed in powers of $(x^2-1)$, is irreducible in $\mathbb{Z}[x]$.   Many Thanks!!    No "ordering" is implied here. The wording of the question was done in similar fashion  as any question in any math/research question. I do not see how a person who is asking for help would be ordering people to help.   Any way back to the topic,  For the first part of the question, I noticed that if n is prime, then T(n,x) satisfies  Eisenstein's Irreducibility Criterion. But I am not sure how to show if T(n,x) is irreducible then n is prime. GCSE: Find the number of person that will go to a party Multirow and Multicolumn with missing lines First, my apologies if this has already been asked/answered.  I wasn't able to find this question via search.  My question comes from Rudin's "Principles of Mathematical Analysis," or "Baby Rudin," Ch 1, Example 1.1 on p. 2.  In the second version of the proof, showing that sets A and B do not have greatest or lowest elements respectively, he presents a seemingly arbitrary assignment of a number $q$ that satisfies equations (3) and (4), plus other conditions needed to show that $q$ is the right number for the proof.  As an exercise, I tried to derive his choice of $q$ so that I may learn more about the problem.  If we write equations (3) as $q = p - (p^2 - 2)x$, we can write (4) as   $$ q^2 - 2 = (p^2 - 2)[1 - 2px + (p^2 - 2)x^2]. $$  Here, we need a rational $x &gt; 0$, chosen such that the expression in $[...]$ is positive.  Using the quadratic formula and the sign of $(p^2 - 2)$, it can be shown that we need   $$ x \in \left(0, \frac{1}{p + \sqrt{2}}\right) \mbox{ for } p \in A, $$  or, for $p \in B$, $x &lt; 1/\left(p + \sqrt{2}\right)$ or $x &gt; 1/\left(p - \sqrt{2}\right)$.  Notice that there are MANY solutions to these equations! The easiest to see, perhaps, is letting $x = 1/(p + n)$ for $n \geq 2$.  Notice that Rudin chooses $n = 2$ for his answer, but it checks out easily for other $n$.  The Question:  Why does Rudin choose $x = 1/(p + 2)$ specifically?  Is it just to make the expressions work out clearly algebraically?  Why doesn't he comment on his particular choice or the nature of the set of solutions that will work for the proof?  Is there a simpler derivation for the number $q$ that I am missing? Sudo doesn't work on Aliases I have added alias ll='ls -la' in /etc/bash.bashrc but sudo ll is not working. Is there a way to "source" bash.bashrc? In a related post, another user suggesting creating an alias for sudo with a space after it. Eg. alias sudo='sudo ' but there wasn't any context to this answer. Should I add this to my bashrc? Seems hackish.  What is the correct method for adding an alias for my sudo one-off commands? I just designed this MPPT solar charge controller which outputs 4.2 V regulated via MPPT, it uses the SPV1040 IC. This will be used on a satellite with 4 side panels, each with 8 solar cells in parallel outputting 2.6 V at approximately 122 Ma. Each panel will have this exact circuit and all the outputs will be connected in parallel to a 3.7 V lithium ion camera battery.  When active only 1 solar panel will be active and the other MPPT circuits will be offline or providing a very low amount of current. How should I connect the 4.2v to the battery, just directly or using some sort of controller to stop charging at 4.2v? Keep in mind the battery will always have a load and it will charge for around 50m in a 90m cycle due to being eclipsed. I would obviously like the battery to last as long as possible so I am not sure what are the implications of constantly having a battery connected to 4.2 V during 50m. Thanks.   The schematic was made based off a simulation made using the ST Edesignsuite directly from the provider.  Excuse my previous question about this, wasn't properly worded. Has the below question been answered here before?  Prove: For a given enclosed volume, a sphere has minimum surface area.  Please provide link or ways to solve it. I know it is a problem of Minima and involves finding derivative and second derivatives. However, how to to frame the leading equations which has to be differentiated?  I am looking for a way to solve only using High School level Calculus. I think there must be an answer. How do I logout from a non-registered account? I have a registered StackOverflow account which I normally log into using OpenID.  Recently I logged out in order to post a question anonymously (supplying a fake name and of my secondary email addresses).  The problem now is that I'm logged in to StackOverflow as this "dummy" user, unable to see a way to log out.  The top menu normally has a "logout" link, but when you aren't fully registered this link is replaced with "register".  There is no "logout" link for me. :(  So..   When logged out there is a "login" link. When logged in there is a "logout" link. When "logged in" with an unregistered account, there is only a "register" link (no "logout"). (How) Can I use existing stapled electrical wire to fish new wire? I nicked an electrical cable while doing a plumbing repair and so need to fix it. I previously  about repairing the damage in place, but there are receptacles 6-10 feet away on either side of the damaged wire, so it may not be too difficult to just pull new wire. Most of the wire is run horizontally through the studs, which is great, but it will at least be stapled at both boxes (and possibly more). The horizontal run is ~18" up from the floor, while the receptacles are ~6". There is also an inside corner the wire is run through. Wire is 12/2.  Is it possible to use the existing wire to fish the new wire, even though the existing wire is stapled? Would I need to open up the wall to remove the staples?  I found a , but that pertains to telephone wires which sometimes use different staples than electrical wires. I have an application running on node and using the mongodb library to establish connection and closing it. But the problem is, from the mongo serverStatus() command i can see that there is still 2k+ current connections still available.  &gt; db.serverStatus().connections { "current" : 2993, "available" : 835867, "totalCreated" : 220841 }   and most of it are having the active: false status.  My questions is, is there a way for me to force close these idle connections which after some time will affect my application with an timeout error.  I tried using the killOp() command but these only works if there is still opid value listed in these idle connections.  Appreciate some feedback on how can handle this kind of situations. HTTP vs HTTPS performance Are there any major differences in performance between http and https?  I seem to recall reading that HTTPS can be a fifth as fast as HTTP.  Is this valid with the current generation webservers/browsers?  If so, are there any whitepapers to support it? I'm talking about this nonsense:   Now, I'm aware that there are problems with the practicalities (or possibilities) of methods involving exotic matter with negative mass, and that kind of thing has been addressed here:   But in this case my question is different and more specific. Sweeping all the other problems of constructing such a beast under the rug, wouldn't this violate causality?  SR says that the simultaneity and relative ordering of events is dependent on the relative motion of the observer, but that no matter how it works out, if event A causes event B, no observer will see B first. One of the many problems with FTL travel (or signals) is that if any information is sent faster than light, there will exist an inertial frame in which the signal arrives before it is sent, a blatant violation of causality. (I think we can all agree, can we not, that the threshold should be extremely high before breaking assumptions that we're in a causal universe?)  So how is any scheme to travel faster than light, even if it may locally satisfy the equations of GR, not a blatant violation causality according to SR?  Is my understanding of GR incomplete and there's something in it that obviates the causality implications of SR? Or am I correct that FTL claims should be dismissed with extreme prejudice on this basis alone? (Pending a serious replicable experiment showing causality to be breakable.) Let $\{K_n \}_{n \in \mathbb{N}}$ be a collection of sets, where $K_n = [n, \infty)$. Why is $\bigcap_{n \in \mathbb{N}} K_{n}$ empty? This question is related to Exercise 2.15 in Baby Rudin, in which the reader is instructed to "[s]how that Theorem 2.36 and its Corollary become false (in $R^1$, for example) if the word 'compact' is replaced by 'closed' or by 'bounded.'"  The relevant theorem and corollary are as follows:  Theorem 2.36: If $\{K_{α}\}$ is a collection of compact subsets of a metric space $X$ such that the intersection of every finite subcollection of $\{K_{α}\}$ is nonempty, then   $\{K_{α}\}$ is nonempty.  Corollary: If $\{K_{n}\}$ is a sequence of nonempty compact sets such that $K_{n}$ contains $K_{n+1},  (n = 1, 2, 3, ...)$, then   $K_n$ is not empty.  My Question: I realize this question and similar ones have been asked elsewhere on MSE, but I've yet to see a straightforward (to me, at least) answer to my question specifically. Usually, for the "closed" part of the exercise, the following collection of closed sets, $\{K_n \}_{n \in \mathbb{N}}$ is used:  $$K_n = [n, \infty), n \in \mathbb{N}.$$  For, the intersection of every finite subcollection of ${K_n}$ is clearly nonempty. Indeed,  $$ \bigcap_{i=1}^{m} K_{n_{i}} = [N, \infty) $$  where $N = \max\{n_1, n_2, ..., n_m\}$.  Then, the assertion is made that   $$ \bigcap_{n=1}^{\infty} K_n = \emptyset. $$  However, I don't see how the same argument can't simply be used, i.e., that, for example, $N \in  \bigcap_{n=1}^{\infty} K_n$ (or maybe, say, $n+1$). Intuitively, this certainly makes sense, I'd say. For, given the archimedean property, it seems that as $n$ approaches infinity, we can always find an $l$ in each increasingly smaller set such that $n &lt; l &lt; \infty$; and so $l \in  \bigcap_{n=1}^{\infty} K_n$.  What is it exactly that I'm misunderstanding or overlooking here? How can I control HDD spin down time? I have 2 HDDs in my PC. Ubuntu is turning off the secondary HDD very quickly after about 15 minutes, which is short for me. I need to control this time. How can I do it?  I tried GNOME power management but did not find it useful. Do I need to use The Loop on pages? I'm writing my first WordPress theme and have a question about the use of The Loop in page templates. The page templates I've looked at all follow basically the same pattern (example from Twenty Twelve):  &lt;?php while ( have_posts() ) : the_post(); ?&gt; &lt;?php get_template_part( 'content', 'page' ); ?&gt; &lt;?php comments_template( '', true ); ?&gt; &lt;?php endwhile; // end of the loop. ?&gt;   But a page will only have one post associated with it so iterating through the posts seems unnecessary. My page template is more readable and seems to work fine:  &lt;?php the_post(); the_title('&lt;h1&gt;', '&lt;/h1&gt;'); the_content(); ?&gt;   Is this a good practice? Are there any downsides? addtocontents not working with certain other packages This is a follow up question on   How do I change the toc dept mid document while using packages (in this case only mathtools).  An example:  \documentclass[a4paper,10pt,oneside]{book}  \usepackage{mathtools}  \begin{document}   \frontmatter             \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \setcounter{tocdepth}{3}  \tableofcontents   \mainmatter   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \appendix   \addtocontents{toc}{\setcounter{tocdepth}{0}}   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}  \end{document}   This example generates an error and very strangely puts an exclamation mark in the ToC as you can see here   however when I comment out the \usepackage{mathtools} it suddenly works again or replacing it with a different package such as \usepackage[T1]{fontenc} also generates no errors.  But this is not limited to just this specific package, certain other packages also introduce the same behavior (I just took this package to keep the example small).