1
2! Copyright (C) 2002-2005 J. K. Dewhurst, S. Sharma and C. Ambrosch-Draxl.
3! This file is distributed under the terms of the GNU Lesser General Public
4! License. See the file COPYING for license details.
5
6!BOP
7! !ROUTINE: r3mm
8! !INTERFACE:
9pure subroutine r3mm(a,b,c)
10! !INPUT/OUTPUT PARAMETERS:
11!   a : input matrix 1 (in,real(3,3))
12!   b : input matrix 2 (in,real(3,3))
13!   c : output matrix (out,real(3,3))
14! !DESCRIPTION:
15!   Multiplies two real $3\times 3$ matrices.
16!
17! !REVISION HISTORY:
18!   Created April 2003 (JKD)
19!EOP
20!BOC
21implicit none
22! arguments
23real(8), intent(in) :: a(3,3),b(3,3)
24real(8), intent(out) :: c(3,3)
25c(1,1)=a(1,1)*b(1,1)+a(1,2)*b(2,1)+a(1,3)*b(3,1)
26c(2,1)=a(2,1)*b(1,1)+a(2,2)*b(2,1)+a(2,3)*b(3,1)
27c(3,1)=a(3,1)*b(1,1)+a(3,2)*b(2,1)+a(3,3)*b(3,1)
28c(1,2)=a(1,1)*b(1,2)+a(1,2)*b(2,2)+a(1,3)*b(3,2)
29c(2,2)=a(2,1)*b(1,2)+a(2,2)*b(2,2)+a(2,3)*b(3,2)
30c(3,2)=a(3,1)*b(1,2)+a(3,2)*b(2,2)+a(3,3)*b(3,2)
31c(1,3)=a(1,1)*b(1,3)+a(1,2)*b(2,3)+a(1,3)*b(3,3)
32c(2,3)=a(2,1)*b(1,3)+a(2,2)*b(2,3)+a(2,3)*b(3,3)
33c(3,3)=a(3,1)*b(1,3)+a(3,2)*b(2,3)+a(3,3)*b(3,3)
34end subroutine
35!EOC
36
37