I'm using the dramatist package to typeset a drama script. Characters are created using the \GCharacter-command. I want to customize that command to have it execute \NewPerson for each new Character created.  To do so, I've looked up the installed dramatist.sty on my system and copied the definition of \GCharacter into my preamble like that:  \renewcommand\GCharacter[3]{     \stepcounter{g\Roman{character}}     \global\@namedef{#3}{{\namefont #2}\xspace}     \global\n@me@ppend@nddef{#3}{\@ppendname}{%         \if@drverse             {\speakstab\speaksfont #2\speaksdel\par\nobreak\addvspace{-\parskip}}         \else             \item[#2\speaksdel]         \fi}     \global\n@me@ppend@nddef{gpersona@\Roman{character}}{%         @\Roman{g\Roman{character}}}{\castfont #1} }   This is the exact definition from the dramatist.sty-file. However, LaTeX complains: ! You can't use \spacefactor in vertical mode. on the first line I use \GCharacter in. How could this be, as I've changed nothing in comparison to the original definition?  In the following MWE, the error occurs in line 19:  \documentclass[a4paper]{scrartcl} \usepackage{dramatist} \usepackage{lipsum}  \renewcommand\GCharacter[3]{     \stepcounter{g\Roman{character}}     \global\@namedef{#3}{{\namefont #2}\xspace}     \global\n@me@ppend@nddef{#3}{\@ppendname}{%         \if@drverse             {\speakstab\speaksfont #2\speaksdel\par\nobreak\addvspace{-\parskip}}         \else             \item[#2\speaksdel]         \fi}     \global\n@me@ppend@nddef{gpersona@\Roman{character}}{%         @\Roman{g\Roman{character}}}{\castfont #1}     %\NewPerson }  \begin{CharacterGroup}{TeX.SX} \GCharacter{A Character}{A Character}{character} \end{CharacterGroup}  \begin{document} \DramPer  \lipsum[1] % Compilation fails with only \DramPer in document \end{document}   Without the \renewcommand, everything works fine:   Any clues on how to fix that error?
Many LaTeX “hacks” begin with \makeatletter and end with \makeatother. What do these commands do?
I have the following diagram:    However, this looks a bit ugly, I would like a version that looks a little bit better. For example, size the last arrow such that the T_\phi is moved to the right.  This is the code which I am using to do this:  \begin{align*}   \xi \colon &amp;\lb \to \mathcal{L}(\hh)\\   &amp;\phi \mapsto T_\phi. \end{align*}   Where \lb and \hh just give the names for those spaces. Does anybody have a suggestion how I would improve the look of this function definition? How to prove $C_1 \|x\|_\infty \leq \|x\| \leq C_2 \|x\|_\infty$? I want to prove the following theorem (no idea whether it has a name):  Let $V = \mathbb{R}^n$ or $\mathbb{C}^n$ and $\|\cdot\|$ be a norm on $V$. Then, there exist $C_1, C_2 &gt; 0$ such that for all $x \in V$:  $$C_1 \|x\|_\infty \leq \|x\| \leq C_2 \|x\|_\infty$$  I first let $x \neq 0$ (otherwise it would be trivial). Then, I divided by $\|x\|_\infty$ and normalized the vector $x$ such that $\|x\|_\infty = 1$. That left me with  $$C_1 \leq \|x\| \leq C_2$$  but I don't see how this could help me or how I could possibly limit an unknown norm. How can I proceed? Or is this the wrong way anyway? Thanks for any answers. Convert XML/HTML Entities into Unicode String in Python python ImportError: No module named primes I have a bunch of SD cards that do not have the little plastic switch for the read only setting. so Windows thinks it’s write protected or something. The card is not write protected by the software lock present on the SD card standard.  I’m using one with tape over the notch and it’s ugly. Also, the Thinkpad slot drags on the tape all the time so I’m afraid it will might loose in there eventually.  So, is there any way to tell Windows to ignore this lame write-protect feature?  I’m not interested on the SD card itself as it’s irrelevant for the issue at hand. Read this question as being about a 5.25” floppy disk drive instead of an SD card if you wish. I’m pretty sure the Windows settings are the same for both, really.  I’m  that there are 3 ways to secure an SD card. I’m talking about only the mechanical switch, which is the responsibility of the host to handle. inputenc Error: Unicode char \u8: not set up for use with LaTeX This is with ref to my previous question .  \documentclass[11pt,table,a4paper]{article} \usepackage{lmodern} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc}  \usepackage{CJKutf8} \usepackage[english,russian]{babel}  \newenvironment{SChinese}{%  \CJKfamily{gbsn}%  \CJKtilde  \CJKnospace}{}   \begin{document}  \selectlanguage{russian}   Это мой первый многоязычный докладе.   Инфантильный гипертрофический стеноз привратника - это серьёзное   \selectlanguage{english}   This is my first multilingual report.   \begin{CJK}{UTF8}{}   \begin{SChinese}     这是我的第一个多语种的报告。   \end{SChinese}   \end{CJK}    \end{document}   when I try to compile it, I get following error message.  LaTeX Warning: Unused global option(s):     [table].  (./data.aux (/usr/local/texlive/2011/texmf-dist/tex/latex/cyrillic/t2acmr.fd)) (/usr/local/texlive/2011/texmf-dist/tex/latex/lm/t1lmr.fd)  LaTeX Font Warning: Font shape `T2A/lmr/m/n' undefined (Font)          using `T2A/cmr/m/n' instead on input line 15.   ! Package inputenc Error: Unicode char \u8:  not set up for use with LaTeX.  See the inputenc package documentation for explanation. Type  H &lt;return&gt;  for immediate help.  ...                                      l.18 ...�ный гипертрофический стеноз привра...   How can I avoid such error message. Is there an easy way to add a hole into an object? If I wanted to add a hole into an object e.g. Create a tube  Is there an easy way to do that?  I haven't seen anything regarding negative space so far in Blender, and it would be really helpful for my project  Thanks in advance! Can the Telekinesis spell be used to manipulate liquids? How can Star Trek: Countdown ever be considered canon? Why does "kill -9 0" end my console session? I just wonder why kill -9 0 ends my tty console session?   What exactly is PID 0, it is not listed on a ps aux? Official StackExchange app says my question is not available? I recently posted a new question on Android Enthusiasts using the official StackExchange app for Android. Right after posting the question, the app said that my question is not available.     The question is not available, it may have been deleted.   Deleted? Already?...  Then I navigated to my user name to see my recent activity. There it was! I could see the question I just posted. But if I tapped on the link to try to open it, the app kept complaining about my question not being available.     The question is not available, it may have been deleted.   But 7 minutes after posting the question, I could see my question. Here are some screenshots that showcase this issue.      This is not the first time this happens. This appears to be more or less normal behavior of the app. I don't use the StackExchange app very often to post questions. But I had exactly the same message come up when I posted a question a few months ago (and some app version numbers earlier).  This is not a major issue, but you should try to address this nevertheless. It's a small bug, but addressing it might imply much bigger changes... which might explain why it's still present... I don't really know, I'm guessing. I just thought I would let you know about it, in case you are not aware of it.  For the record, the phone is Galaxy S4 Plus (GT-I9506) running Android 4.4.2. Version number of the app is 1.0.50. Intuitive/direct proof that a rectangle partitioned into rectangles each with at least one integer side must itself have an integer side A challenge problem asked to show that if rectangle $R$ with axis-parallel sides is partitioned into finitely many subrectangles $R_1,R_2,\ldots,R_n$ (also with axis-parallel sides), such that each $R_i$ has at least one integer side length, then $R$ must also have at least one integer side length. The only proof I've seen, although simple, is quite unintuitive. Namely you look at the integral  $$ \int_R e^{2 \pi i (x+y)} dx dy $$ and note that the integral is $0$ if and only if $R$ has an integer side length, and then note that by assumption the integral is $0$ over all the $R_i$, hence summing the integral over all $R_i$ gives that the integral is also $0$ over $R$. Can someone give a more direct/intuitive argument that doesn't use voodoo like a complex-valued integral? I want to change my thesis topic (to the extent that the ethos is still in tact) but my advisor does not agree. What can I do? I am doing a phd where my aim is to solve a problem A which is very interesting. My supervisor has got a lot of connections in a technology B and he claims to be an expert in B. I came to this group because of these accomplishments. But soon I realized that B is not really a great technology for A.   So in my phd proposal I proposed a method which encompasses B but is more general (say R). Now I realize that I do not want to use B at all because my preliminary results are not encouraging. In fact, I am inclined to use E as a base technique which does not have any impact on R.  But my supervisor, who is interested in only publishing in B  and frowns upon everything else (it was a nightmare to convince him to let me work on R) is dead against it. He says that he is an expert in B and his vision of the group is not inclined with me trying other things.  There are other professors in my university who have worked in E and could collaborate but my supervisor won't collaborate with people from outside his kingdom. I also know professors from outside my university who could help me if needed. I could knock the doors of school committee in order to  help me but that would create a lot of problems as my supervisor wields a lot of power and influence everywhere.    Another query is, is it ethical to collaborate with people outside the university (of course after letting my supervisor know) for my PhD work. My Masters supervisor would be happy to help me out.  Edit: After looking at comments, I am thinking that after all, it is MY PhD. Yes, I have spent 1.5 years, but 1.5 years is left. Why should I spend any moment of my life on something I find to be not exciting, particularly less exciting because it is forced on me. And in those 1.5 years I learnt to write well and also learnt 'A' which is important. Its not total waste. My supervisor has his agenda, and why should I give up mine to make him happy? His vision is fine, but he does not have the right to force his vision on me. Is the 64-Bit version of Ubuntu only compatible with AMD CPUs? I was told that computers with more than 2 gig's memory need a 64 bit operating system to utilize all RAM.  Is the 64bit Ubuntu download really JUST for AMD processors? I am asking because the disk image I downloaded says AMD64.  So will my new Intel 2.3Ghz Core i3 Dual Core processor work with 64 bit Ubuntu?  It runs the 64bit version of Windows without any qualm. Generalized RBF Kernels There is the notion of Generalized RBF Kernels, for example in "Towards Optimal Bag-of-Features for Object Categorization and Semantic Video Retrieval" from Jiang (1) or in formula (2.72) in  (2).  They define: Gen. RBF Kernel: $e^{-pd(x,y)}$, where (1) says d can be any distance function and (2) requires it to be a metric.  I now have been wondering for a long time: Is a function defined by $e^{-pd(x,y)}$ where d is a metric always a Mercer's Kernel? I think in (2) it sounds like it, but if it were true, not many people know of it, since they are still looking to prove that $e^{-EMD(x,y)}$ is a kernel, where EMD = Earth Mover's Distance, which is a metric.  If its not a Mercer's Kernel - do you know of any counter example? I'm using Windows 7 as the host machine with VMWare Workstation 9. I created a virtual machine Ubuntu Desktop 12.04 LTS 64 bit version. There are two options for log in, Ubuntu and Ubuntu 2D. Whenever I log in to Ubuntu, the task bar will not show up, is like having a black margin all around the desktop background and only the center is visible.  I wish I could attached a pic, but I need at least 10 reputation.  When I move my mouse over the left side of the desktop I can see that something is there but it is shown only as a black square. I tried deleting the virtual machine I created for Ubuntu and re-installed it, but it keeps appearing like that.  When I switched to log in with the Ubuntu 2D version everything worked alright. I could see the task bar, the icons, the clock etc. What might be causing this problem? How does the lens diameter influence photo quality? I have tested two different 50mm lenses in my camera. One was a Nikkor 50mm ∅52mm. The other one was a Sigma 50mm ∅72mm. I took some pictures with both lenses using the same setup for aperture and shutter speed, but couldn't notice significant differences in the quality of the pictures.   So, how does the diameter affects the photo quality, if it does? What advantages would the ∅72mm lens have over the ∅52mm one? Is there a JavaScript equivalent of Java's class.getName()? Is “might could” a correct construct? How much time do I have to wait before I can sell another car? I was wondering: How much time does it take until the cooldown resets and I can sell another car in the GTA Online LS Customs Garage?