punctuation marks have different fonts in and out of equations in xetex

Question

I am using xelatex to create a document in Armenian. I have the line

\setmainfont [Mapping=tex-text, Scale=MatchUppercase] {DejaVu Serif}

in my tex file to change the font to DejaVu Serif for the text. However the equations are still in Computer Modern. As a result punctuation marks, such as "," are different in and out of equation. This looks a bit ugly, because commas are very different in DejaVu Serif and Computer Modern. How can I fix this?

Answer 1

The mathspec package allows you to set maths text fonts. Unfortunately this doesn't actually solve the punctuation problem. Code to do that was posted here: Punctuation marks in math mode in xetex/mathspec Here's an example.

% !TEX TS-program = XeLaTeX

\documentclass{article}
\usepackage{amsmath} % must be loaded before mathspec

\usepackage{mathspec}
\setmainfont [Mapping=tex-text, Scale=MatchUppercase] {DejaVu Serif}
\setmathsfont(Latin,Digits){DejaVu Serif}


% The following code is from https://tex.stackexchange.com/q/38711/2693
\makeatletter
\DeclareMathSymbol{,}{\mathpunct}{\eu@LatinLowercase@symfont}{`,}
\DeclareMathSymbol{.}{\mathord}{\eu@LatinLowercase@symfont}{`.}
\DeclareMathSymbol{<}{\mathrel}{\eu@LatinLowercase@symfont}{`<}
\DeclareMathSymbol{>}{\mathrel}{\eu@LatinLowercase@symfont}{`>}
\DeclareMathSymbol{/}{\mathord}{\eu@LatinLowercase@symfont}{`/}
\XeTeXDeclareMathSymbol{^^^^2026}{\mathinner}{\eu@LatinLowercase@symfont}{"2026}[\mathellipsis]
\makeatother


\begin{document}
This, a sample sentence, is some regular text.

\[
g(n) = 
\begin{cases}
\frac{2}{3}n & \text{if } n \equiv 0 \mod 3,\\
\frac{4}{3}n + \frac{1}{3} & \text{if } n \equiv 1 \mod 3,\\
\frac{4}{3}n - \frac{1}{3} & \text{if } n \equiv 2 \mod 3.
\end{cases}
\]
\end{document}