I have the following plot:
\begin{figure}
\centering
\begin{tikzpicture}
\begin{axis}[
scale only axis,
width = 0.8\columnwidth,
height = 0.8\columnwidth,
enlargelimits = 0.15,
xlabel = {\# Classes loaded},
xlabel style = {
at = {(1,0)},
anchor = south east
},
ylabel = {\# Methods called},
ylabel style = {
at = {(0,1)},
anchor = north west,
rotate = -90
},
ticklabel style = {/pgf/number format/fixed},
cycle list = {
{black, fill=black!50, mark=square*},
{black, fill=black!100, mark=*},
{black, fill=black!100, mark=o},
{black, fill=black!100, mark=triangle},
}]
\addplot+[only marks] coordinates {
(251, 839)
(172, 463)
(174, 467)
(269, 958)
(206, 639)
(180, 515)
(209, 641)
(225, 623)
(208, 605)
(329, 1227)
};
\label{pgfplots:java}
\addplot+[only marks] coordinates {
(4286, 11546)
(4277, 11384)
(4295, 11632)
(4313, 11726)
(4251, 11250)
(4311, 11851)
(4321, 11714)
(4260, 11381)
(4261, 11304)
(4323, 11866)
};
\label{pgfplots:jruby}
\addplot+[only marks] coordinates {
(1781, 5128)
(1777, 5119)
(1740, 4892)
(1813, 5377)
(1780, 5123)
(2107, 6052)
(1778, 5135)
(1745, 4995)
(1719, 4826)
(1749, 5031)
};
\label{pgfplots:clojure}
\addplot+[only marks] coordinates {
(2726, 7663)
(2701, 7576)
(2881, 7917)
(2761, 7788)
(2211, 6298)
(2799, 7872)
(2747, 7876)
(2147, 6053)
(2789, 7844)
(2719, 7753)
};
\label{pgfplots:jython}
\end{axis}
\end{tikzpicture}
\caption{Number of classes loaded and methods called at least once by the Clojure~(\ref{pgfplots:clojure}), Java~(\ref{pgfplots:java}), JRuby~(\ref{pgfplots:jruby}), and Jython~(\ref{pgfplots:jython}) benchmarks.}
\end{figure}
which produces the following chart:

I have plenty of those in my paper and latex gives an error: LaTeX Error: Too many unprocessed floats..., therefore I've decided to externalize them. Now the question is how to externalize the caption together with the legend. All my legends are stored in captions.
Thanks in advance!
\clearpagesomewhere in the document). That said, external images have a worth on their own, so the question might be of interest to you anyway. – Christian Feuersänger May 25 '13 at 18:29