PGF/TikZ and Sans Serif Fonts

Question

I have a TikZ/PGF file created directly by a graphing package of the form \begin{tikzpicture}{dimensions} ... \end{tikzpicture}. The file uses \pgftext[...]{\selectfont{Some text here or \boldmath$math$}} to render text.

By default, when I include the file in my document, the text is typeset in the default font for my document (Latin Modern Serif). However, I wish for all of my figures/graphs to be typeset in a sans-serif font (Latin Modern Sans). How can I go about this?

Ideally, I would like to accomplish this without having to edit the file directly (so just changing the LaTeX around where I include it).

Update: Minimal Example

\begin{tikzpicture}
 \pgftext{\selectfont{Hello \boldmath$W \times orld$}}
\end{tikzpicture}

Anything which can correctly set that piece of text to be sans-serif should do the trick.

Answer 1

There are two issues here. One is to make the default font sans-serif so that \selectfont selects it. The other is to get the math to use bold, sans-serif letters.

For the first, \renewcommand{\familydefault}{\sfdefault} works. See “How do you change the document font in LaTeX?” from StackOverflow.

For the second, any new math font versions set up are deselected by \boldmath. In fact, \boldmath expands to \mathversion{bold}. So we need to override the font selections for the bold math version to choose bold, sans-serif letters. This is accomplished by \SetSymbolFont{letters}{bold}{OML}{cmbr}{bx}{it} (There is no Latern Modern math alphabet; Computer Modern Bright is a suggested replacement).

Here is the complete working example. You just need to add two lines to the preamble, and nothing to the automatically-generated part.

\documentclass{article}
\usepackage{tikz}
\usepackage{lmodern}
\SetSymbolFont{letters}{bold}{OML}{cmbr}{bx}{it}
\renewcommand{\familydefault}{\sfdefault}

\begin{document}
\begin{tikzpicture}
 \pgftext{\selectfont{Hello \boldmath$W \times orld$}}
\end{tikzpicture}
\end{document}

Answer 2

Some more details could have been very helpful. To choose a certain font style for your picture you simply have to give appropriate options to the tikzpicture environment.

\begin{tikzpicture}[font=\sffamily]
% picture contents
\end{tikzpicture}

For a global setting you may try \tikzstyle{every picture}+=[font=\sffamily] in the preamble.