deriv Function

public function deriv(f, dh) result(df)

Arguments

Type IntentOptional Attributes Name
real(kind=8), intent(in), dimension(:) :: f
real(kind=8), intent(in) :: dh

Return Value real(kind=8), dimension(size(f))


Source Code

  function deriv(f,dh) result(df)
    real(8),dimension(:),intent(in) :: f
    real(8),intent(in)              :: dh
    real(8),dimension(size(f))      :: df
    integer                         :: i,L
    L=size(f)
    df(1)= (f(2)-f(1))/dh
    do i=2,L-1
       df(i) = (f(i+1)-f(i-1))/(2.d0*dh)
    enddo
    df(L)= (f(L)-f(L-1))/dh
  end function deriv