r3cross.f90

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! Copyright (C) 2002-2005 J. K. Dewhurst, S. Sharma and C. Ambrosch-Draxl.
! This file is distributed under the terms of the GNU Lesser General Public
! License. See the file COPYING for license details.

!BOP
! !ROUTINE: r3cross
! !INTERFACE:
pure subroutine r3cross(x,y,z)
! !INPUT/OUTPUT PARAMETERS:
!   x : input vector 1 (in,real(3))
!   y : input vector 2 (in,real(3))
!   z : output cross-product (out,real(3))
! !DESCRIPTION:
!   Returns the cross product of two real 3-vectors.
!
! !REVISION HISTORY:
!   Created September 2002 (JKD)
!EOP
!BOC
implicit none
! arguments
real(8), intent(in) :: x(3),y(3)
real(8), intent(out) :: z(3)
z(1)=x(2)*y(3)-x(3)*y(2)
z(2)=x(3)*y(1)-x(1)*y(3)
z(3)=x(1)*y(2)-x(2)*y(1)
end subroutine
!EOC