stellinstall/r8mkherm1_8f_source.html

      subroutine r8mkherm1(fun,x,nx,fherm)

C

C  create a data set for Hermite interpolation, from evaluation of

C  function and derivatives.  function of 1 indep. coordinate.

C

C  input:

C

!============

! idecl:  explicitize implicit INTEGER declarations:

      IMPLICIT NONE

      INTEGER, PARAMETER :: R8=selected_real_kind(12,100)

      INTEGER nx,ix

!============

! idecl:  explicitize implicit REAL declarations:

      real*8 fun,dfdx

!============

      external fun                      ! passed real function(x,dfdx)

      real*8 x(nx)                        ! x coordinate array

C

C  the passed function fun must have the interface:

C

C        real function <name>(x,dfdx)

C  where x is input, the function returns the function value and the

C  argument dfdx returns as output the function derivative at x.

C

C  output:

C

      real*8 fherm(0:1,nx)                ! function data & derivative

C

C  fherm(0,j) = function value f at x(j)

C  fherm(1,j) = derivative df/dx at x(j)

C

C----------------------------

C

      do ix=1,nx

         fherm(0,ix)=fun(x(ix),dfdx)

         fherm(1,ix)=dfdx

      enddo

C

      return

      end