Postscript lacks a lot of basic operators such as tan, acos, asin, cosh, sinh, tanh, acosh, asinh, atanh, exp (with e base). cos, sin give result in degrees.

pst-math provides all those operators in a header file pst-math.pro with wrappers pst-math.sty and pst-math.tex.

In addition, sinc, gauss, gammaln and bessel are implemented (only partially for the latter). pst-math is designed essentially to work with pst-plot but can be used in whatever PS code (such as pstricks SpecialCoor "!", useful to put labels).

This work is in progress! PS is limited to single precision so complex operators like gammaln can give erroneous results. The author is Christophe Jorssen.