[fpc-pascal] Special math. functions (erf, erfc, ...)

Jeff Miller miller at psy.otago.ac.nz
Sun Dec 17 23:40:13 CET 2006

This is slightly off-topic, but nonetheless somewhat
relevant to these special math functions...

Can anyone explain what is the precision of fpc's
built-in math functions like sqrt, ln, exp, and so on?

According to the online documentation, these take
a ValReal argument and return a ValReal result:
  e.g.:  function sqrt(d: ValReal):ValReal;
But what exactly is a ValReal?  Real? Double? Extended?

It would be ideal if these math functions would take arguments
of different precision and return results in the same precision.
Is that what happens?

I am asking because I need extended precision versions
of sqrt, etc, and I do not believe fpc provides that
(at least by default).  I have seen the mpcalc unit,
but I was hoping for a solution that doesn't involve
a special unit (with special coding).

Thank you for any information or suggestions...


miller at psy.otago.ac.nz

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