mchgm.f90

数值计算和数值分析在Fortran下的特殊函数库,是数值计算的必备

MODULE chgm_func
 
! From the book "Computation of Special Functions"
!      by Shanjie Zhang and Jianming Jin
!   Copyright 1996 by John Wiley & Sons, Inc.
! The authors state:
!   "However, we give permission to the reader who purchases this book
!    to incorporate any of these programs into his or her programs
!    provided that the copyright is acknowledged."
 
IMPLICIT NONE
INTEGER, PARAMETER  :: dp = SELECTED_REAL_KIND(12, 60)
 
CONTAINS


SUBROUTINE chgm(a, b, x, hg)

!       ===================================================
!       Purpose: Compute confluent hypergeometric function
!                M(a,b,x)
!       Input  : a  --- Parameter
!                b  --- Parameter ( b <> 0,-1,-2,... )
!                x  --- Argument
!       Output:  HG --- M(a,b,x)
!       Routine called: GAMMA for computing