A long time ago...
  Jakob wrote some code, now resident (rotting?)
on Google code.
https://code.google.com/archive/p/graph2svg/downloads

At the time he use fxsl and exsl for the math(s).

IMHO this is well worth bringing up to date.
I asked Jakob and received no reply.

Saxon math 'extension' only lacks abs,  from
my early trials?

If anyone with a mathematical bent has time
to do the xslt world a favour, I would certainly
appreciate it.

regards



-- 
Dave Pawson
XSLT XSL-FO FAQ.
Docbook FAQ.