Let us consider the following example :    \documentclass[12pt,twoside,a4paper]{book} \usepackage[usenames,dvipsnames]{pstricks} \usepackage{epsfig} \usepackage{pst-grad} % For gradients \usepackage{pst-plot} % For axes \begin{document} \scalebox{1} % Change this value to rescale the drawing. { \begin{pspicture}(0,-0.02)(2.68,0.02) \psline[linewidth=0.04cm](0.0,0.0)(2.66,0.0) \end{pspicture}  } \end{document}   Whenever I compile this code with kile in Ubuntu14.04 shows four errors :    Undefine control sequence }    Undefine control sequence }    Undefine control sequence }    Undefine control sequence }  But I don't know why such errors are occurring. Please help.
I have a problem with this file tex:  \begin{document} \begin{figure} \begin{center} \begin{pspicture}(0,0)(1,3.8) \psline{-&lt;}(0,0)(0,.2) \psline{-}(0,.2)(0,.4) \psline{*-&gt;}(0,.4)(0,.9) \psline{-*}(0,.9)(0,1.4) \psline{-&lt;}(0,1.4)(0,2.4) \psline{-}(0,2.4)(0,3.4) \psline{*-}(0,3.4)(0,3.6) \psline{&gt;-}(0,3.6)(0,3.8) \rput(1,.4){$y=0$}%testo \rput(1,1.4){$y=1$} \rput(1,3.4){$y=3$} \end{pspicture} \end{center} \caption{} \end{figure} \end{document}   but I don't understand where is the error.
Is there a way I can see all the versions that are in the archives that I have configured in sources.list. I can see the last version of each archive withapt-get policy, but how can I see them all?  Is there any way that this can also include PPA and anything in sources.list.d? What should happen if a logo I made is similar to another? Note: This is a canonical post created so that we can close the many similar questions as duplicates as discussed in .   We have created a logo for a client and they love it. We've already started preparing the materials that will feature the new logo.   However, after we had created the logo, we found a logo for another company that looks eerily similar. We did not intentionally create the new logo to look like the one of the other company, in fact we didn't even know it existed beforehand, but it does regardless.  What should we do? Is this plagiarism? Can our client use the logo we have created? Should they? Or do we need to come up with another logo that's more different? Is it possible to learn a neural networks for a constant target? I saw a paper () where they learn L based on the following cost function: $$(D_1L(q(k-1), q(k)) + D_2L(q(k),q(k+1)))² = 0$$ Here $D$ is the derivative with respect to ith argument of L. This can be obtained via automatic differentiation and it is fully compatible with backpropagation. So the target is always zero independently of the input of L but how does the optimization method knows the real values of L for a given input? I mean as long as the cost function is satisfied with a zero value the model is learning but it can be learning wrong values for L. For instance, if the real value of $D_1L(q(k-1), q(k))$ is 10 then the real value of $D_2L(q(k),q(k+1))$ has to be -10. However the neural network may be learning wrong values for L as long as they are symmetric, for example -3 and 3. This is an ill posed problem due to the infinite possible solutions. Am I missing something or the method in that paper simply doesn't make any sense? Is it possible to learn a neural network in regression task with constant target? Edit: The goal is not to predict always that value. The goal is to learn L by predicting always zero (see the cost function). The question here is in order to learn L in such a way that it respects the cost function, there are infinite possible solutions, for instance if $D1L(q(k−1),q(k))$ = x then D2L(q(k),q(k+1))=-x and its sum gives 0 respecting the cost function. But as you can see x can assume any value as long as the cost function is respected, when in reality the goal is to learn a specific L. But the optimization doesn't know a priori value for L so I guess it should just assume a random value for x. In the paper they don't mention the ill posedness of the problem, either they solved it or not. I would like to know if what I'm thinking makes sense or if I'm just missing something. Let $p$ a cut point of a connected space $(X, \mathcal{T})$ and suppose $C$ and $D$ form a separation  of $X-\{p\}$, i.e $$X-\{p\}=C \cup D$$ Prove that $C \cup \{p\}$ is conected. I have this idea: Since $p$ is a cut point then $X-\{ p \}$ is not connected, and since $C$ and $D$ form a separation of $X- \{p \}$ then $X-\{p \} = C \cup D$, and also $C \cup D$ is not connected. And also $$C \cap \overline{D}= \overline{C} \cap D= \emptyset$$ I need an idea to continue please How do you correctly say large numbers Debugging a custom-bib bst file that crashes on book items I created my own bibliography file with custom-bib (makebst), but when I run it with a reference to a book I get:  $ bibtex PhD [...normal output] Database file #1: PhD.bib You can't pop an empty literal stack for entry oecd2001brc while executing---line 1504 of file wdsphd.bst   The only thing on that line is a high-level ITERATE call.   The style was created with these options:  %% merlin.mbs  (with options: `head,exlang,annote,seq-no,nm-rvvc,dt-beg,yr-par,xmth,tit-qq,qx,bt-qq,vol-bf,volp-sp,num-xser,pub-date,isbn,issn,doi,english,pp,ord,url,url-nl,nfss,,{}') %% english.mbs  (with options: `exlang,annote,seq-no,nm-rvvc,dt-beg,yr-par,xmth,tit-qq,qx,bt-qq,vol-bf,volp-sp,num-xser,pub-date,isbn,issn,doi,english,pp,ord,url,url-nl,nfss,,{}') %% merlin.mbs  (with options: `tail,exlang,annote,seq-no,nm-rvvc,dt-beg,yr-par,xmth,tit-qq,qx,bt-qq,vol-bf,volp-sp,num-xser,pub-date,isbn,issn,doi,english,pp,ord,url,url-nl,nfss,,{}')   The code for book items looks like:  FUNCTION {book} { output.bibitem   author empty$     { format.editors "author and editor" output.check     }     { format.authors output.nonnull       crossref missing$         { "author and editor" editor either.or.check }         'skip$       if$     }   if$   format.btitle "title" output.check   crossref missing$     { format.bvolume output       new.block       format.number.series output       new.sentence       format.publisher.address output     }     {       new.block       format.book.crossref output.nonnull     }   if$   format.edition output   format.isbn output   format.doi output   new.block   format.note output   fin.entry   write.url }   And this is the entry:  @book{oecd2001brc,  author = {OECD},  doi = {10.1787/9789264193550-en},  isbn = {9789264186903},  publisher = {OECD Publishing},  title = {{Biological Resource Centres: Underpinning the future of life sciences and biotechnology}},  url = {http://www.oecd-ilibrary.org/science-and-technology/biological-resource-centres\_9789264193550-en},  year = {2001} }   Is there a way to get a better stacktrace from bibtex? What I have now doesn 't really tell me what is going on. If it can be fixed simply, help would also be appreciated. How to get Scilab 6.0.1 working on Ubuntu 18.04 LTS? I have installed clean Ubuntu MATE 18.04 LTS and installed Scilab from repository here with    sudo apt-get update sudo apt-get install scilab   After installation I tried to launch it from GUI (Applications → Other → Scilab) - it does not start. Then I tried to launch it from terminal with scilab command. Terminal output is as follows:  $ scilab /usr/bin/scilab-bin: error while loading shared libraries: libjava.so: cannot open shared object file: No such file or directory   so it can't find Java. I reported  about this problem.  I checked existence of libjava.so:  $ dpkg -S libjava.so   openjdk-11-jre-headless:amd64: /usr/lib/jvm/java-11-openjdk-amd64/lib/libjava.so   so it is in place.  What should I do to get Scilab 6.0.1 working on Ubuntu 18.04 LTS? We've upgraded some machines to Windows 10 and realized there were some updates which updated as required. However, I realized there was no option available to stop the download similar to that on Windows 7 and 8.1. The only way I could stop the download was to stop the Windows Update service.  My question is does anyone know of a way to stop auto updates or is stopping the service is the only solution? Allow the owner of a post to approve a suggested edit even if it was rejected by reviewers For , the answer given on 7 Feb about how to edit the subject line in the new format of Gmail does not work for me.   There is no box on the left with a down arrow to options to reply, forward or edit subject in my version. There is a book on the right offering options to    Reply Reply to all Forward Filter message Print Delete Report spam Report phising Show original Message text garbled Translate message Mark answered    But, no option to edit subject Why Does the Transaction Log Keep Growing or Run Out of Space? I read this book in the mid-nineties, probably written in the 80s or 90s.  It’s set in the near future, where the world has experienced a sudden glaciation.  Most of the United States and Europe is now covered with ice.  Civilization has collapsed for the most part. The protagonist is a drifter with strange-colored eyes (yellow, I think).  Because of his weird eyes, he’s never really fit in anywhere.  He moves from place to place just trying to survive, but somehow he discovers that the new ice-age did not occur naturally.  It was engineered by extraterrestrials, to make their work easier.  They’re looking for the plans for a super-weapon - a weapon that can cause any star to go nova.  A rival group of aliens hid the plans for this weapon by encoding the information in the human genome millions of years ago.  The marker to identify humans who carry this gene is - you guessed it - yellow-colored eyes. Compton scattering vs. photoelectric effect Say a photon hits some atom.  What determines whether there will be a photoelectric effect (photon is absorbed, electron is released) or whether there will be a Compton scattering (the photon is  scattered at some angle, and the electron is released with another direction)? Prove $\frac{|a+b|}{1+|a+b|}<\frac{|a|}{1+|a|}+\frac{|b|}{1+|b|}$. Prove that for every $a, b\in R\setminus\{0\}$ is correct this inequality:  $$\frac{|a+b|}{1+|a+b|}&lt;\frac{|a|}{1+|a|}+\frac{|b|}{1+|b|}.$$ The use of weak references is something that I've never seen an implementation of so I'm trying to figure out what the use case for them is and how the implementation would work. When have you needed to use a WeakHashMap or WeakReference and how was it used? I'm currently reading a little deeper into the Axiom of Choice, and I'm pleasantly surprised to find it makes the arithmetic of infinite cardinals seem easy. With AC follows the Absorption Law of Cardinal Arithmetic, which states that for $\kappa$ and $\lambda$ cardinal numbers, the larger infinite and the smaller nonzero, then $\kappa+\lambda=\kappa\cdot\lambda=\max(\kappa,\lambda)$.  I was playing around with the equation $k+\aleph_0=\mathfrak{c}$ for some cardinal $k$. From the above, it follows that $\mathfrak{c}=k+\aleph_0=\max(k,\aleph_0)$, which implies $k=\mathfrak{c}$.  I'm curious, can we still show $k=\mathfrak{c}$ without the Axiom of Choice? Is it maybe possible to bound $\mathfrak{c}-\aleph_0$ above and below by $\mathfrak{c}$? But then I'm not quite sure such algebraic manipulations even mean anything, or work like that here. Certainly normal arithmetic does not! Thanks. What’s the rule for using “who” and “whom” correctly? GCSE: Find the number of person that will go to a party Today in the feed on the Android Stack Exchange app there is a Stack Overflow blog post. This post had the site icon next to it for  rather than the proper site logo (Meta).        Stack Exchange Android App Version 1.0.73 and 1.0.74 Android 5.1 on a Moto X (2013) running stock firmware.  Same behavior on a Nexus 7 (flo) running Android 6.0 (stock).  This issue also happens on the iOS app.    The most recent featured SO blog post (as of 17 Nov) is showing up with the "edX" site logo.  The logo is seemingly randomly incorrect. EDIT: Summary  I think I've found the best definition of what I want thanks to the discussion with @M. Tibbits:  When I open or refresh the SO, I get a notification of new activities that are of interest to me. Today these are (hard-coded): answers to my questions and comments addressed to me. I want a bit more control over it, that's all.     Yes, I've read  and , but I think I add new (good :) ) reasons for re-asking it:  The first question was answered before this so handy "inbox" notification feature was implemented. So now using favorites for "watching" a question is wrong, IMHO, for 2 reasons:   it splits essentially the same functionality (of getting notified when there is an activity you are interested in) between 2 very different user interfaces it's cumbersome - I need to: 1) add question to favorites; 2) click on my profile dropdown; 3) click on the "favorites" line; 4) see all my favorites with recent activity; 5) select the one I watch; 6) repeat this process occasionally to get updates; and 7) possibly remove the question from favorites at the end. All this as opposed to this little red button when there are news.   Favorites are different in nature that watching. I add a question to Favorites when I find the answers useful to me in my work, so I may want to have it handy in the future. By watching an interesting question I will be able to decide whether I want it in faviorites, after I see the answers.  EDIT: I see that I was not clear enough.  I want to add a question to Favorites when:   it has some good answers the question and answers are relevant in my work I want to keep them handy as my long-term (persistent) knowledge base   I want to watch a question for short while (matter of days/weeks) when:   it is interesting / relevant I want to follow it to see what are the answers. Then I can decide whether I want it in my favorites   As you see, the main differentiators are good answers and long/short term. For short-term, automatic notification is better.  Bottom line, all I ask is "watch this question" checkbox (which may expire after say a week if there is a need to free resources)