most recent 30 from http://mathoverflow.net 2013-05-18T06:32:21Z http://mathoverflow.net/feeds/question/24737 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/24737/the-upper-hat-of-an-octahedral-diagram-in-latex Mikhail Bondarko 2010-05-15T12:28:42Z 2010-07-07T02:12:21Z

<p>I would like to draw an octahedral diagram in my paper; I would prefer to present it as the 'upper hat' + the 'lower hat' (as it is common in the texts on triangulated categories). Could anyone tell me where I can find this diagram (certainly, the 'upper hat part' is sufficient) written down in latex. Maybe, someone could just share with me his own latex realization of this diagram (so that I could replace the original names of objects and morphisms by the ones I need)?</p>

http://mathoverflow.net/questions/24737/the-upper-hat-of-an-octahedral-diagram-in-latex/24756#24756 Tara Holm 2010-05-15T14:33:54Z 2010-05-15T14:33:54Z

<p>I think that this is an easy exercise in xy-pic. The exact diagram you want may not be in this <a href="http://sdconsult.no/linux/teTeX/xypic/" rel="nofollow">user's guide</a>, but the basics of xy-pic are easy enough that you should be able to create what you want.</p>

http://mathoverflow.net/questions/24737/the-upper-hat-of-an-octahedral-diagram-in-latex/24799#24799 Niall Murphy 2010-05-15T19:21:40Z 2010-05-16T15:44:01Z

<p>The same example given in xy-pic done in Tikz: More examples and code are at <a href="http://www.texample.net/tikz/examples/" rel="nofollow">http://www.texample.net/tikz/examples/</a> and the manual <a href="http://mirror.ctan.org/graphics/pgf/base/doc/generic/pgf/pgfmanual.pdf" rel="nofollow">http://mirror.ctan.org/graphics/pgf/base/doc/generic/pgf/pgfmanual.pdf</a></p> <pre><code>\documentclass[a4paper]{article} \usepackage{tikz} \usetikzlibrary{shapes} \begin{document} \begin{tikzpicture}[shorten &lt;=7pt,shorten &gt;=7pt] \node [name=oct,regular polygon,regular polygon sides=4,minimum size= 12em] {}; \node at (oct.corner 1) [name=octCorner1] {$Z$}; \node at (oct.corner 2) [name=octCorner2] {$X'$}; \node at (oct.corner 3) [name=octCorner3] {$Z'$}; \node at (oct.corner 4) [name=octCorner4] {$X$}; \node at (oct.center) [name=octCenter] {$Y$}; \draw [-stealth] (oct.corner 2) -- node [right] {$[1]$} (oct.corner 3); \draw [-stealth] (oct.corner 1) -- (oct.corner 2); \draw [-stealth] (oct.corner 1) -- (oct.corner 4); \draw [-stealth] (oct.corner 3) -- node [above] {$[1]$} (oct.corner 4); \draw [-stealth] (oct.corner 2) -- node [right] {$[1]$} (oct.center); \draw [-stealth] (oct.corner 4) -- (oct.center); \draw [-stealth] (oct.center) -- (oct.corner 3); \draw [-stealth] (oct.center) -- (oct.corner 1); \end{tikzpicture} \end{document} </code></pre> <hr> <p>Changed from an octagon. </p>

http://mathoverflow.net/questions/24737/the-upper-hat-of-an-octahedral-diagram-in-latex/24801#24801 Donu Arapura 2010-05-15T19:22:44Z 2010-05-15T19:30:30Z

<p>Mikhail,</p> <p>Here's an upper cap in xy-pic</p> <p>\xymatrix{ X'\ar[rd]^{[1]}\ar[dd]^{[1]} &amp; &amp; Z\ar[ll] \\ &amp; Y\ar[ru]\ar[ld] &amp; \\ Z'\ar[rr]^{[1]} &amp; &amp; X\ar[lu]\ar[uu] }</p> <p>at least it's enough of one to get you started. Note that I didn't construct it by hand. I have a script for building these kinds of diagrams visually:</p> <p><a href="http://www.math.purdue.edu/~dvb/scripts/arraymaker" rel="nofollow">http://www.math.purdue.edu/~dvb/scripts/arraymaker</a></p> <p>If it's useful to you, help yourself.</p>