The regularized gamma functions are defined by

and

where and are incomplete Gamma Functions and is a complete Gamma Function. Their derivatives are

**References**

Press, W. H.; Flannery, B. P.; Teukolsky, S. A.; and Vetterling, W. T.
*Numerical Recipes in FORTRAN: The Art of Scientific Computing, 2nd ed.* Cambridge, England:
Cambridge University Press, pp. 160-161, 1992.

© 1996-9

1999-05-25