program main !*****************************************************************************80 ! !! MAIN is the main program for SOLVE_TEST. ! ! Discussion: ! ! SOLVE_TEST tests the SOLVE library. ! ! Licensing: ! ! This code is distributed under the GNU LGPL license. ! ! Modified: ! ! 29 May 2014 ! ! Author: ! ! John Burkardt ! implicit none call timestamp ( ) write ( *, '(a)' ) '' write ( *, '(a)' ) 'SOLVE_TEST' write ( *, '(a)' ) ' FORTRAN90 version' write ( *, '(a)' ) ' Test the SOLVE library.' call test01 ( ) ! ! Terminate. ! write ( *, '(a)' ) '' write ( *, '(a)' ) 'SOLVE_TEST' write ( *, '(a)' ) ' Normal end of execution.' write ( *, '(a)' ) '' call timestamp ( ) stop 0 end subroutine test01 ( ) !*****************************************************************************80 ! !! TEST01 demonstrates how a 3X3 linear system can be set up and solved. ! ! Licensing: ! ! This code is distributed under the GNU LGPL license. ! ! Modified: ! ! 29 May 2014 ! ! Author: ! ! John Burkardt ! implicit none integer ( kind = 4 ), parameter :: n = 3 real ( kind = 8 ) a(n,n) real ( kind = 8 ) b(n) real ( kind = 8 ) x(n) write ( *, '(a)' ) '' write ( *, '(a)' ) 'TEST01' write ( *, '(a)' ) ' R8MAT_FS solves a linear system with Gauss elimination.' ! ! Set the array. ! a(1,1) = 1.0 a(1,2) = 2.0 a(1,3) = 3.0 a(2,1) = 4.0 a(2,2) = 5.0 a(2,3) = 6.0 a(3,1) = 7.0 a(3,2) = 8.0 a(3,3) = 0.0 ! ! Set the right hand side. ! b(1) = 14.0 b(2) = 32.0 b(3) = 23.0 ! ! Request the solution of A*x=b. ! call r8mat_fs ( n, a, b, x ) call r8vec_print ( n, x, ' Solution:' ); return end