# [XeTeX] On an ugly hack to mathbf only in the local style.

Tue Nov 13 16:12:24 CET 2012

On Tue, Oct 30, 2012 at 2:21 AM, Michaël Cadilhac <michael at cadilhac.name> wrote:
> Hi there folks,
>
> I have gotten used to write vectors in my documents as $\vec{v}$.
> $\vec$, basically, is a mathbf.  Naturally, if I have vectors v_1,
> v_2, v_3, I'd like to write \vec{v_1}, \vec{v_2}, \vec{v_3}.  But
> here, I want to mathbf only the v.  Thus I used this ugly hack,
> contributed by fine people at StackExchange, which (1) saves the font
> in which a mathbf text would be displayed and (2) changes to mathbf
> ONLY the font of the current style:
>
> \def\vec#1{%
>   %% Gather all the fonts -- text, script, script script --.
>   \setbox0\hbox{$\mathbf{\xdef\vec at ts{\the\textfont\fam}% > \xdef\vec at ss{\the\scriptfont\fam}% > \xdef\vec at sss{\the\scriptscriptfont\fam}}$}%
>   \def\vec at font##1##2{##1 0=##2 ##1 1=##2}%
>   %% Return in the right style, apply the bf font ONLY for the local style.
>   \mathchoice{\hbox{$\displaystyle\vec at font{\textfont}{\vec at ts} #1$}}%
>         {\hbox{$\textstyle\vec at font{\textfont}{\vec at ts} #1$}}%
>         {\hbox{$\scriptstyle\vec at font{\scriptfont}{\vec at ss} #1$}}%
>         {\hbox{$\scriptscriptstyle\vec at font{\scriptscriptfont}{\vec at sss} #1$}}}%
>
> I do admit I have only the slightest clue of how this precisely works;
> especially, I'm not sure why I added \vec at font to set so many font
> families.  However, it did work, and I went with it.
>
> Then I switched to XeTeX --- I wanted to use the XITS fonts.  And as
> any ugly hack, mine wasn't supposed to be supported any longer; can't
> blame anyone but myself here.
>
> Thus I'm searching for some help to find a clean^H^H^H^H^Hworking
> solution for this problem.  Any help?

Hi there,