program main !*****************************************************************************80 ! !! MAIN is the main program for MXM_SERIAL. ! ! Licensing: ! ! This code is distributed under the GNU LGPL license. ! ! Modified: ! ! 30 October 2011 ! ! Author: ! ! John Burkardt ! implicit none real ( kind = 8 ), allocatable :: a(:,:) real ( kind = 8 ) angle real ( kind = 8 ), allocatable :: b(:,:) real ( kind = 8 ), allocatable :: c(:,:) integer ( kind = 4 ) i integer ( kind = 4 ) j integer ( kind = 4 ) k integer ( kind = 4 ) n real ( kind = 8 ), parameter :: pi = 3.141592653589793D+00 real ( kind = 8 ) s call timestamp ( ) write ( *, '(a)' ) ' ' write ( *, '(a)' ) 'MXM_SERIAL:' write ( *, '(a)' ) ' FORTRAN90 version' write ( *, '(a)' ) ' Compute matrix product C = A * B.' n = 2000 write ( *, '(a,i8)' ) ' The matrix order N = ', n allocate ( a(1:n,1:n) ) allocate ( b(1:n,1:n) ) allocate ( c(1:n,1:n) ) ! ! Loop 1: Evaluate A. ! s = 1.0D+00 / sqrt ( real ( n, kind = 8 ) ) do i = 1, n do j = 1, n angle = 2.0D+00 * pi * ( i - 1 ) * ( j - 1 ) / real ( n, kind = 8 ) a(i,j) = s * ( sin ( angle ) + cos ( angle ) ) end do end do ! ! Loop 2: Copy A into B. ! do i = 1, n do j = 1, n b(i,j) = a(i,j) end do end do ! ! Loop 3: Compute C = A * B. ! do i = 1, n do j = 1, n c(i,j) = 0.0D+00 do k = 1, n c(i,j) = c(i,j) + a(i,k) * b(k,j) end do end do end do write ( *, '(a,g14.6)' ) ' C(100,100) = ', c(100,100) ! ! Free memory. ! deallocate ( a ) deallocate ( b ) deallocate ( c ) ! ! Terminate. ! write ( *, '(a)' ) ' ' write ( *, '(a)' ) 'MXM_SERIAL:' write ( *, '(a)' ) ' Normal end of execution.' write ( *, '(a)' ) ' ' call timestamp ( ) stop end subroutine timestamp ( ) !*****************************************************************************80 ! !! TIMESTAMP prints the current YMDHMS date as a time stamp. ! ! Example: ! ! 31 May 2001 9:45:54.872 AM ! ! Licensing: ! ! This code is distributed under the GNU LGPL license. ! ! Modified: ! ! 18 May 2013 ! ! Author: ! ! John Burkardt ! ! Parameters: ! ! None ! implicit none character ( len = 8 ) ampm integer ( kind = 4 ) d integer ( kind = 4 ) h integer ( kind = 4 ) m integer ( kind = 4 ) mm character ( len = 9 ), parameter, dimension(12) :: month = (/ & 'January ', 'February ', 'March ', 'April ', & 'May ', 'June ', 'July ', 'August ', & 'September', 'October ', 'November ', 'December ' /) integer ( kind = 4 ) n integer ( kind = 4 ) s integer ( kind = 4 ) values(8) integer ( kind = 4 ) y call date_and_time ( values = values ) y = values(1) m = values(2) d = values(3) h = values(5) n = values(6) s = values(7) mm = values(8) if ( h < 12 ) then ampm = 'AM' else if ( h == 12 ) then if ( n == 0 .and. s == 0 ) then ampm = 'Noon' else ampm = 'PM' end if else h = h - 12 if ( h < 12 ) then ampm = 'PM' else if ( h == 12 ) then if ( n == 0 .and. s == 0 ) then ampm = 'Midnight' else ampm = 'AM' end if end if end if write ( *, '(i2.2,1x,a,1x,i4,2x,i2,a1,i2.2,a1,i2.2,a1,i3.3,1x,a)' ) & d, trim ( month(m) ), y, h, ':', n, ':', s, '.', mm, trim ( ampm ) return end