Hi,

I am not a specialist, but I use the « btex etex » commands, such as
	dotlabel.bot (btex \switchtobodyfont[10pt] \strut $R$ etex, z1)

I just tested with the latest beta, and everything works fine, but not the \pmatrix construct (I tried also with ${k}\choose{n}$, which works fine too. 
I put my test file in which some maths is used in a MetaPost graphic here:
	http://dl.dropbox.com/u/4316076/test-graphique.tex

	http://dl.dropbox.com/u/4316076/test-graphique.pdf


Best regards: OK

On 30 nov. 2011, at 20:59, Hans van der Meer wrote:

> I would like to put some math in metapost pictures. For the moment I am using textext for the typesetting in my metapost macro: pic := textext("\setbox0=\hbox{\color["&textcolor&"]"&labeltext&"}\dp0=0pt\box0");
> picture pic will be placed in the metapost figure.
> 
> Simple math like $p=2$ works fine, but the system chokes on something like the following matrix:
> $\pmatrix{p_{0|0}\cr}$ (it does fine in ConTeXt itself).
> 
> The error is: ! Only one # is allowed per tab.
> system > tex > error on line 6 in file Info/kanaalmatrix.tex: Only one # is allowed per tab ...
> 
> Perhaps I am too optimistic about textext's possibilities. But how can I accomplish the placement of these and more elaborate formulae in metapost pictures using ConTeXt? It is of the essence for a series of Powerpoint slides I am preparing, wheein these formulae must be placed as individual pictures.
> 
> Hans van der Meer
> 
> 
> 
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