unicode math font smaller than the text

Question

I have a problem with unicode-math. When I set the document at 12pt, the maths font remains 10pt, as shown in the following example:

\documentclass[12pt,fleqn,oneside]{article}
\usepackage{amsmath}
\usepackage[no-math]{fontspec}
  \setmainfont[Ligatures=TeX]
     {TeX Gyre Heros}

\usepackage{unicode-math}
\setmathfont{Latin Modern Math}
\setmathfontface\mathrm{Latin Modern Roman}

\begin{document}
This is an example~$y = \tan \text{angle}$
\end{document}

I don't really get along with unicode-math. Could you help me to fix this problem?

Answer 1

Scale to match:

\documentclass[12pt,fleqn,oneside]{article}
\usepackage{amsmath}

\usepackage[no-math]{fontspec}
\usepackage{unicode-math}

\setmainfont{TeX Gyre Heros}

\setmathfont{Latin Modern Math}[Scale=MatchLowercase]
\setmathrm{Latin Modern Roman}[Scale=MatchLowercase]

\begin{document}

This is an example~$y = \tan \text{angle}$

Another $y_{\mathrm{up}}$

\end{document}

Answer 2

Empirically, I found the solution of scaling maths fonts of a factor 1.2 as in the example below:

\documentclass[12pt,fleqn,oneside]{article}
\usepackage{amsmath}
\usepackage[no-math]{fontspec}
  \setmainfont[Ligatures=TeX]
     {TeX Gyre Heros}

\usepackage{unicode-math}
\setmathfont{Latin Modern Math}[Scale=1.2]
\setmathfontface\mathrm{Latin Modern Roman}[Scale=1.2]


\begin{document}
This is an example~$y = \tan \text{angle}$
\end{document}

It is certainly not the most aesthetic way, but it works, at least with the two fonts I am using. If you find a most aesthetic solution, I will be pleased to see it, though.