S2PV Subroutine

  1. astro_module.f90
  2. astro_module
  3. S2PV

public subroutine S2PV(theta, phi, r, td, pd, rd, pv)

Convert position/velocity from spherical to Cartesian coordinates.

Status: vector/matrix support routine.

History

  • IAU SOFA revision: 2000 November 25

Arguments

TypeIntentOptionalAttributesName
real(kind=wp), intent(in) :: theta

longitude angle (radians)
real(kind=wp), intent(in) :: phi

latitude angle (radians)
real(kind=wp), intent(in) :: r

radial distance
real(kind=wp), intent(in) :: td

rate of change of THETA
real(kind=wp), intent(in) :: pd

rate of change of PHI
real(kind=wp), intent(in) :: rd

rate of change of R
real(kind=wp), intent(out), dimension(3,2):: pv

pv-vector

Called by

proc~~s2pv~~CalledByGraph proc~s2pv S2PV proc~fk425 FK425 proc~fk425->proc~s2pv proc~starpv STARPV proc~starpv->proc~s2pv proc~fk524 FK524 proc~fk524->proc~s2pv proc~fk52h FK52H proc~fk52h->proc~starpv proc~starpm STARPM proc~starpm->proc~starpv proc~h2fk5 H2FK5 proc~h2fk5->proc~starpv proc~fk54z FK54Z proc~fk54z->proc~fk524 proc~pmsafe PMSAFE proc~pmsafe->proc~starpm

Contents

Source Code

S2PV

Source Code

    subroutine S2PV ( theta, phi, r, td, pd, rd, pv )

    implicit none

    real(wp),intent(in) :: theta !! longitude angle (radians)
    real(wp),intent(in) :: phi !! latitude angle (radians)
    real(wp),intent(in) :: r !! radial distance
    real(wp),intent(in) :: td !! rate of change of THETA
    real(wp),intent(in) :: pd !! rate of change of PHI
    real(wp),intent(in) :: rd !! rate of change of R
    real(wp),dimension(3,2),intent(out) :: pv !! pv-vector

    real(wp) :: st, ct, sp, cp, rcp, x, y, rpd, w

    st = sin(theta)
    ct = cos(theta)
    sp = sin(phi)
    cp = cos(phi)
    rcp = r*cp
    x = rcp*ct
    y = rcp*st
    rpd = r*pd
    w = rpd*sp - cp*rd

    pv(1,1) = x
    pv(2,1) = y
    pv(3,1) = r*sp
    pv(1,2) = - y*td - w*ct
    pv(2,2) =   x*td - w*st
    pv(3,2) = rpd*cp + sp*rd

    end subroutine S2PV