[metapost] Calling external programs from MetaPost

[Giuseppe Bilotta]

Hello all,

as part of a rather complext MetaPost program I need to some
rather complex computation for which MP numerical limits are
simply insurmuntable obstacles. So my idea would be to call
an external program to do the complex computations, and then
read the output data back in.

The reading of the data back in is, obviously, not a
problem: I can do that with input by writing appropriate
MP code from the external program.

I cannot however find a way to call the external program
itself. The simplest thing I can think of is to use TeX's
write18 (assuming it's enabled, of course) in an appropriate
btex .. etex or some such construct.

So the question is: is it possible to call external programs
from MetaPost itself, or is TeX the only way?

Thanks in advance for the assistance,

-- 
Giuseppe "Oblomov" Bilotta