sphere Subroutine

private pure subroutine sphere(x, y, z, rho, theta, phi)

cartesian to spherical coordinates (angles in radians)

Arguments

Type IntentOptional Attributes Name
real(kind=wp), intent(in) :: x

x = r cos(phi) cos (theta)
real(kind=wp), intent(in) :: y

y = r cos(phi) sin(theta)
real(kind=wp), intent(in) :: z

z = r sin(phi)
real(kind=wp), intent(out) :: rho

distance
real(kind=wp), intent(out) :: theta

longitude
real(kind=wp), intent(out) :: phi

latitude

Source Code

    pure subroutine sphere (x, y, z, rho, theta, phi)

    implicit none

    real(wp), intent (in) :: x       !! x = r cos(phi) cos (theta)
    real(wp), intent (in) :: y       !! y = r cos(phi) sin(theta)
    real(wp), intent (in) :: z       !! z = r sin(phi)
    real(wp), intent (out) :: rho    !! distance
    real(wp), intent (out) :: theta  !! longitude
    real(wp), intent (out) :: phi    !! latitude

    real(wp) :: r

    theta = zero
    phi = zero
    rho = sqrt (x*x+y*y+z*z)
    r = sqrt (x*x+y*y)
    if (r /= zero) then
        theta = modulo (atan2(y, x), twopi)
        phi = atan2 (z, r)
    end if

    end subroutine sphere