PVXPV Subroutine

  1. astro_module.f90
  2. astro_module
  3. PVXPV

public subroutine PVXPV(a, b, axb)

Outer (=vector=cross) product of two pv-vectors.

Status: vector/matrix support routine.

Note

If the position and velocity components of the two pv-vectors are ( Ap, Av ) and ( Bp, Bv ), the result, A x B, is the pair of vectors ( Ap x Bp, Ap x Bv + Av x Bp ). The two vectors are the cross-product of the two p-vectors and its derivative.

History

  • IAU SOFA revision: 2006 November 13

Arguments

TypeIntentOptionalAttributesName
real(kind=wp), intent(in), dimension(3,2):: a

first pv-vector
real(kind=wp), intent(in), dimension(3,2):: b

second pv-vector
real(kind=wp), intent(out), dimension(3,2):: axb

A x B

Calls

proc~~pvxpv~~CallsGraph proc~pvxpv PVXPV proc~cpv CPV proc~pvxpv->proc~cpv proc~ppp PPP proc~pvxpv->proc~ppp proc~pxp PXP proc~pvxpv->proc~pxp

Contents

Source Code

PVXPV

Source Code

    subroutine PVXPV ( a, b, axb )

    implicit none

    real(wp),dimension(3,2),intent(in) :: a !! first pv-vector
    real(wp),dimension(3,2),intent(in) :: b !! second pv-vector
    real(wp),dimension(3,2),intent(out) :: axb !! A x B

    real(wp) :: wa(3,2), wb(3,2), axbd(3), adxb(3)

    !  Make copies of the inputs.
    call CPV ( a, wa )
    call CPV ( b, wb )

    !  A x B = position part of result.
    call PXP ( wa(1,1), wb(1,1), axb(1,1) )

    !  A x Bdot + Adot x B = velocity part of result.
    call PXP ( wa(1,1), wb(1,2), axbd )
    call PXP ( wa(1,2), wb(1,1), adxb )
    call PPP ( axbd, adxb, axb(1,2) )

    end subroutine PVXPV