problems with displaymath/equation inside caption environment
Ben Bolker
I am having some minor problems incorporating an equation in a caption
(LaTeX on TeX 3.0 running on a Sun SPARCStation) ... although the
output produced is actually what I want, so the problem is really just
an annoyance (error messages etc.)
When I try to run a document of the following form through LaTeX, I
get errors (as listed below). I get similar errors using \displaymath
instead of \equation , and it doesn't seem to be a fragile-command problem.
(I've read the LaTeX book and the FAQ list, and not found any answers.
Please forgive me if the answer is obvious.)
Please respond by e-mail if possible.
Thanks.
Ben (b...@eno.princeton.edu)
here's the file:
------------------------------
\documentstyle[11pt]{article}
\begin{document}
Stuff before the figure.
More stuff before the figure.
\begin{figure}
\caption[]{
Stuff before the equation.
\begin{equation}
x = y + z
\end{equation}
Stuff after the equation.
}
\end{figure}
\end{document}
------------------------------
and this is what happens:
This is TeX, C Version 3.0
(test.tex
LaTeX Version 2.09 <7 Dec 1989>
(/usr/princeton/common/lib/tex3.0/inputs/article.sty
Document Style `article' <16 Mar 88>.
(/usr/princeton/common/lib/tex3.0/inputs/art11.sty)) (test.aux)
! You can't use `\eqno' in restricted horizontal mode.
\endequation ->\eqno
\@eqnnum $$\global \@ignoretrue
\end #1->\csname end#1\endcsname
\@checkend {#1}\if@endpe \global \let \@gte...
<argument> ...{equation} x = y + z \end {equation}
Stuff after the equation.
\@makecaption ... \setbox \@tempboxa \hbox {#1: #2
} \ifdim \wd \@tempboxa >\...
\@caption ...fnum@#1\endcsname }{\ignorespaces #3}
\par \endgroup
l.20 }
? [1] (test.aux) )
Output written on test.dvi (1 page, 460 bytes).
Transcript written on test.log.
--
Benjamin Bolker Dep't of Ecology and Evolutionary Biology,
b...@eno.princeton.edu Princeton University
Donald Arseneau
>I am having some minor problems incorporating an equation in a caption
>(LaTeX ...
That's a result of the poor definition of \@makecaption in the
standard styles. It starts out putting the caption in a horizuntal
save-box, but displayed math is not allowed there. This is a
feature, not a bug, because displayed equations in a caption
are really *bad*.
>output produced is actually what I want,
This is very surprising! Try it with a short caption.
>\begin{equation}
It appears you are even numbering the equation! That number will be
out of order when the figure floats. I do use a version of \@makecaption
that would allow displayed math, but, as a matter of style, my advice
is just: put the displayed equation back in the main text where it
belongs!
Donald Arseneau as...@reg.triumf.ca