Span a figure or table over 2 columns in a 3-or-more column document

Question

Is it possible to span a float over 2 columns in a 3 (or more) column document obtained by the multicol package?

Something like this, for example:

I know it's easy to span afloat across all columns using the figure* environment; or on 1 column by using the center environment.

But I have absolutely no idea how a crate a float that spans 2 columns in a 3 column document. Or, taking it a step further, a float that has a variable horizontal length, spanning for instance 1.5 or 2.5 columns (i.e. the wrapfig equivalent for multiple columns).

Thanks.

Answer 1

multicol doesn't support floats but if you don't mind a bit of hand adjustment it's possible to get most arrangements. If you are working on one book for several weeks such hand adjustments are quite feasible, if automatically typesetting thousands of documents an hour from some catalogue database, less so.

Basically let TeX decide where the natural column break is, then force a break at that point and add some space to take the image and caption.

\documentclass{article}

\usepackage{multicol,graphicx,capt-of}

\def\z{\stepcounter{enumi}\Roman{enumi} one two three four five six seven eight nine ten. }

\begin{document}

\begin{multicols}{3}

\z\z\z\z\z\z\z\z\z\z \z\z\z\z\z\z\z\z\z\z
Red Green blue yellow. Red Green blue yel-{\parfillskip0pt\par}

\columnbreak
\vspace*{16\baselineskip}
\noindent
\begin{picture}(0,0)
\put(0,110){\parbox{\dimexpr2\columnwidth+\columnsep}{\centering
\includegraphics[width=\linewidth]{example-image}

\captionof{figure}{an image}}}
\end{picture}%
low.
\z\z\z\z\z\z\z\z\z\z \z\z



Apples oranges ba-{\parfillskip0pt\par}

\columnbreak
\vspace*{16\baselineskip}
\noindent nanas.
\z\z\z\z\z\z\z\z
\z\z\z\z\z\z\z\z\z\z \z\z\z\z\z\z\z\z\z\z
\z\z\z\z\z\z\z\z\z\z \z\z\z\z\z\z\z\z\z\z
\end{multicols}
\end{document}