I am using the answer from Arrow between parts of equation in LaTeX.

\newcommand{\tikzmark}[1]{\tikz[overlay,remember picture] \node (#1) {};}

  \begin{tikzpicture}[overlay,remember picture,out=315,in=225,distance=0.4cm]
    \draw[->,red,shorten >=3pt,shorten <=3pt] (a.center) to (b.center);

This correctly draws an arrow when I compile it with latex then dvipdf, but for some reason the arrowhead does not appear when I compile with pdflatex.

latex -version and pdflatex -version both output:

pdfTeX 3.1415926-1.40.10-2.2 (TeX Live 2009/Debian)
kpathsea version 5.0.0
Copyright 2009 Peter Breitenlohner (eTeX)/Han The Thanh (pdfTeX).
There is NO warranty.  Redistribution of this software is
covered by the terms of both the pdfTeX copyright and
the Lesser GNU General Public License.
For more information about these matters, see the file
named COPYING and the pdfTeX source.
Primary author of pdfTeX: Peter Breitenlohner (eTeX)/Han The Thanh (pdfTeX).
Compiled with libpng 1.2.46; using libpng 1.2.46
Compiled with zlib; using zlib
Compiled with poppler version 0.18.2

I am also wondering what the 3.1415626 is doing there...

  • 6
    3.1415626 is the version number of TeX. Each new version adds a digit of pi. Since all veresions are only bug fixes, when TeX will reach version pi, it will be bug-free. – JLDiaz Dec 15 '12 at 14:33
  • 3
    Welcome to TeX.sx! I don't have a TeX Live 2009 at hand, but with the current version the arrow appears correctly. A tip: never use $$ with LaTeX, in that case \[...\] should be used. – egreg Dec 15 '12 at 14:41
  • Thanks, updated answer. Any clue at all why it works with latex and dvipdf but not with pdflatex? – cg505 Dec 15 '12 at 14:55
  • Try using \coordinate instead of \node in \tikzmark's definition. Also remove .center when using those points. – JLDiaz Dec 15 '12 at 15:24
  • Same result, no arrowhead with pdflatex. – cg505 Dec 15 '12 at 17:00