mitsh0.f90

来自「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」· F90 代码 · 共 25 行

MODULE itsh0_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."

! The results for x >= 30. agree with those in the program only to about
! 6 decimal places.

IMPLICIT NONE
INTEGER, PARAMETER  :: dp = SELECTED_REAL_KIND(12, 60)
 
CONTAINS


SUBROUTINE itsh0(x, th0)

!       ===================================================
!       Purpose: Evaluate the integral of Struve function
!                H0(t) with respect to t from 0 and x
!       Input :  x   --- Upper limit  ( x