program main !*****************************************************************************80 ! !! cube_monte_carlo_test() tests cube_monte_carlo(). ! ! Licensing: ! ! This code is distributed under the MIT license. ! ! Modified: ! ! 16 January 2014 ! ! Author: ! ! John Burkardt ! implicit none call timestamp ( ) write ( *, '(a)' ) ' ' write ( *, '(a)' ) 'CUBE_MONTE_CARLO_TEST():' write ( *, '(a)' ) ' FORTRAN90 version' write ( *, '(a)' ) ' Test CUBE_MONTE_CARLO().' call test01 ( ) ! ! Terminate. ! write ( *, '(a)' ) ' ' write ( *, '(a)' ) 'CUBE_MONTE_CARLO_TEST' write ( *, '(a)' ) ' Normal end of execution.' write ( *, '(a)' ) ' ' call timestamp ( ) stop 0 end subroutine test01 ( ) !*****************************************************************************80 ! !! TEST01 estimates integrals over the unit cube in 3D. ! ! Licensing: ! ! This code is distributed under the MIT license. ! ! Modified: ! ! 16 January 2014 ! ! Author: ! ! John Burkardt ! implicit none integer, parameter :: rk = kind ( 1.0D+00 ) integer, parameter :: m = 3 real ( kind = rk ) cube01_volume integer e(m) integer :: e_test(m,10) = reshape ( (/ & 0, 0, 0, & 1, 0, 0, & 0, 1, 0, & 0, 0, 1, & 2, 0, 0, & 1, 1, 0, & 1, 0, 1, & 0, 2, 0, & 0, 1, 1, & 0, 0, 2 /), (/ m, 10 /) ) integer j integer n real ( kind = rk ) result(10) real ( kind = rk ), allocatable :: value(:) real ( kind = rk ), allocatable :: x(:,:) write ( *, '(a)' ) ' ' write ( *, '(a)' ) 'TEST01' write ( *, '(a)' ) ' Use CUBE01_SAMPLE to estimate integrals ' write ( *, '(a)' ) ' over the interior of the unit cube in 3D.' write ( *, '(a)' ) ' ' write ( *, '(a)' ) & ' N' // & ' 1' // & ' X' // & ' Y ' // & ' Z' // & ' X^2' // & ' XY' // & ' XZ' // & ' Y^2' // & ' YZ' // & ' Z^2' write ( *, '(a)' ) ' ' n = 1 do while ( n <= 65536 ) allocate ( value(1:n) ) allocate ( x(1:m,1:n) ) call cube01_sample ( n, x ) do j = 1, 10 e(1:m) = e_test(1:m,j) call monomial_value ( m, n, e, x, value ) result(j) = cube01_volume ( ) * sum ( value(1:n) ) & / real ( n, kind = rk ) end do write ( *, '(2x,i8,10(2x,g14.6))' ) n, result(1:10) deallocate ( value ) deallocate ( x ) n = 2 * n end do write ( *, '(a)' ) ' ' do j = 1, 10 e(1:m) = e_test(1:m,j) call cube01_monomial_integral ( e, result(j) ) end do write ( *, '(2x,a8,10(2x,g14.6))' ) ' Exact', result(1:10) return end