Using the LaTeX ‘float’ package with Pandoc

2019-01-29

When I convert markdown documents to pdf files using LaTeX and Pandoc, LaTeX is very helpful at placing images optimally to minimise whitespace. a basic pandoc command might look like this:

pandoc -f markdown -t latex  -o output.pdf input.md

The issue is, when I’m using pandoc with markdown, I often don’t care about the placement of images. I’m normally making short documents for note-taking or something like that. As a result, I normally place images in the text in the place I want them to appear in the pdf output.

After a bit of googling for inspiration, I found two methods of doing this. The first, is very simple and tells pandoc not to create figures, but instead just to include images inline.

pandoc -f markdown-implicit_figures -t pdf -o output.pdf input.md

This is fine, but it removes centering on the images, and removes the option for me to include a caption with ![CAPTION HERE](img/diagram.png).

A better option I think, is to allow LaTeX to use the float package in order to place images using attributes such as [H] to force images to appear where they appear in the source.

I already have a LaTeX template that I use for pandoc, called simple_doc.latex. It lives in ~/.pandoc/templates/ so it can be linked to easily in pandoc commands.

The relevant piece of simple_doc.latex is:

$if(graphics)$
\usepackage{graphics} 
\usepackage{graphicx}
\usepackage{float}
\makeatletter

% Define max width and max height arguments to be conditional on img size
\def\maxwidth{\ifdim\Gin@nat@width>\linewidth\linewidth\else\Gin@nat@width\fi}
\def\maxheight{\ifdim\Gin@nat@height>\textheight\textheight\else\Gin@nat@height\fi}
\makeatother

% Scale images if necessary, so that they will not overflow the page
% margins by default, and it is still possible to overwrite the defaults
% using explicit options in \includegraphics[width, height, ...]{}
\setkeys{Gin}{width=0.5\maxwidth,height=0.5\maxheight,keepaspectratio}

\let\origfigure\figure
\let\endorigfigure\endfigure
\renewenvironment{figure}[1][2] {
    \expandafter\origfigure\expandafter[H]
} {
    \endorigfigure
}

$endif$

I got the inspiration for this from this Stack Overflow question .