fsum2.f90

Go to the documentation of this file.

subroutine fsum2( f, t, ffnul, ffcos, ffsin, mharm)                       
!-----------------------------------------------------------------------  
! fourier synthesis of general  function f(t) at single point t.          
!-----------------------------------------------------------------------  

  use itm_types

  implicit none

  integer(itm_i4), intent(in) :: mharm
  real(r8), intent(out) :: f
  real(r8), intent(in) :: t, ffnul
  real(r8), dimension(mharm), intent(in) :: ffcos, ffsin

  real(r8) :: co, si, c, s, ca, sum
  integer(itm_i4) :: m

  co = cos(t)  
  si = sin(t)
  c = 1._r8
  s = 0._r8
  sum = .5_r8 * ffnul
  do m = 1,mharm
    ca = c * co - s * si
    s = s * co + c * si
    c = ca
    sum = sum + ffcos(m) * c + ffsin(m) * s
  end do
  f = sum

  return
end subroutine fsum2