Compute derivative for Hankel function of second kind of order n.
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
integer | :: | n |
The order of the function. |
|||
real(kind=rk), | intent(in) | :: | x |
The evaluation point. |
The function value.
function hankel2_n_derivative(n,x) result(der)
! --------------------------------------------------------------------------
!> The order of the function.
integer :: n
!> The evaluation point.
real(kind=rk), intent(in) :: x
!> The function value.
complex(kind=rk) :: der
! --------------------------------------------------------------------------
! --------------------------------------------------------------------------
! Calculate the derivative by recursive relation
der = 0.5_rk*( hankel2_n(n-1,x)-hankel2_n(n+1,x) )
end function hankel2_n_derivative