// File recommented by recomment.C // on Jul 7 2014 at 20:37:06. // # include # include # include # include using namespace std; # include "fem2d_bvp_serene.hpp" int main ( ); void test01 ( ); double a1 ( double x, double y ); double c1 ( double x, double y ); double exact1 ( double x, double y ); double exact_ux1 ( double x, double y ); double exact_uy1 ( double x, double y ); double f1 ( double x, double y ); void test02 ( ); void test03 ( ); double a3 ( double x, double y ); double c3 ( double x, double y ); double exact3 ( double x, double y ); double exact_ux3 ( double x, double y ); double exact_uy3 ( double x, double y ); double f3 ( double x, double y ); //****************************************************************************80 int main ( ) //****************************************************************************80 // // Purpose: // // MAIN is the main program for FEM2D_BVP_SERENE_TEST. // // Discussion: // // FEM2D_BVP_SERENE_TEST tests the FEM2D_BVP_SERENE library. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // { timestamp ( ); cout << "\n"; cout << "FEM2D_BVP_SERENE_TEST\n"; cout << " C++ version\n"; cout << " Test the FEM2D_BVP_SERENE library.\n"; test01 ( ); test02 ( ); test03 ( ); // // Terminate. // cout << "\n"; cout << "FEM2D_BVP_SERENE_TEST\n"; cout << " Normal end of execution.\n"; cout << "\n"; timestamp ( ); return 0; } //****************************************************************************80 void test01 ( ) //****************************************************************************80 // // Purpose: // // TEST01 carries out test case #1. // // Discussion: // // Use A1, C1, F1, EXACT1, EXACT_UX1, EXACT_UX1. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // { double e1; double e2; double h1s; int i; int inc; int j; int k; int mn; int nx = 5; int ny = 5; int show11; double *u; double uexact; double *x; double x_first; double x_last; double *y; double y_first; double y_last; cout << "\n"; cout << "TEST01\n"; cout << " Solve - del ( A del U ) + C U = F \n"; cout << " on the unit square with zero boundary conditions.\n"; cout << " A1(X,Y) = 1.0\n"; cout << " C1(X,Y) = 0.0\n"; cout << " F1(X,Y) = 2*X*(1-X)+2*Y*(1-Y)\n"; cout << " U1(X,Y) = X * ( 1 - X ) * Y * ( 1 - Y )\n"; cout << "\n"; cout << " Number of X grid values NX = " << nx << "\n"; cout << " Number of Y grid values NY = " << ny << "\n"; mn = nx * ny; // // Geometry definitions. // x_first = 0.0; x_last = 1.0; x = r8vec_linspace_new ( nx, x_first, x_last ); y_first = 0.0; y_last = 1.0; y = r8vec_linspace_new ( ny, y_first, y_last ); show11 = 0; u = fem2d_bvp_serene ( nx, ny, a1, c1, f1, x, y, show11 ); if ( nx * ny <= 25 ) { cout << "\n"; cout << " I J X Y U Uexact Error\n"; cout << "\n"; k = 0; for ( j = 0; j < ny; j++ ) { if ( ( j % 2 ) == 0 ) { inc = 1; } else { inc = 2; } for ( i = 0; i < nx; i = i + inc ) { uexact = exact1 ( x[i], y[j] ); cout << setw(4) << i << " " << setw(4) << j << " " << setw(8) << x[i] << " " << setw(8) << y[j] << " " << setw(14) << u[k] << " " << setw(14) << uexact << " " << setw(14) << fabs ( u[k] - uexact ) << "\n"; k = k + 1; } } } e1 = fem2d_l1_error_serene ( nx, ny, x, y, u, exact1 ); e2 = fem2d_l2_error_serene ( nx, ny, x, y, u, exact1 ); h1s = fem2d_h1s_error_serene ( nx, ny, x, y, u, exact_ux1, exact_uy1 ); cout << "\n"; cout << " l1 norm of error = " << e1 << "\n"; cout << " L2 norm of error = " << e2 << "\n"; cout << " Seminorm of error = " << h1s << "\n"; delete [] u; delete [] x; delete [] y; return; } //****************************************************************************80 double a1 ( double x, double y ) //****************************************************************************80 // // Purpose: // // A1 evaluates A function #1. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double A1, the value of A(X,Y). // { double value; value = 1.0; return value; } //****************************************************************************80 double c1 ( double x, double y ) //****************************************************************************80 // // Purpose: // // C1 evaluates C function #1. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double C1, the value of C(X,Y). // { double value; value = 0.0; return value; } //****************************************************************************80 double exact1 ( double x, double y ) //****************************************************************************80 // // Purpose: // // EXACT1 evaluates exact solution #1. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double EXACT1, the value of U(X,Y). // { double value; value = x * ( 1.0 - x ) * y * ( 1.0 - y ); return value; } //****************************************************************************80 double exact_ux1 ( double x, double y ) //****************************************************************************80 // // Purpose: // // EXACT_UX1 evaluates the derivative of exact solution #1. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double EXACT_UX1, the value of dUdX(X,Y). // { double value; value = ( 1.0 - 2.0 * x ) * ( y - y * y ); return value; } //****************************************************************************80 double exact_uy1 ( double x, double y ) //****************************************************************************80 // // Purpose: // // EXACT_UY1 evaluates the derivative of exact solution #1. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double EXACT_UY1, the value of dUdY(X,Y). // { double value; value = ( x - x * x ) * ( 1.0 - 2.0 * y ); return value; } //****************************************************************************80 double f1 ( double x, double y ) //****************************************************************************80 // // Purpose: // // F1 evaluates right hand side function #1. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double F1, the value of F(X,Y). // { double value; value = 2.0 * x * ( 1.0 - x ) + 2.0 * y * ( 1.0 - y ); return value; } //****************************************************************************80 void test02 ( ) //****************************************************************************80 // // Purpose: // // TEST02 checks the basis functions. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // { int i; int j; int seed; double *v; double *vx; double *vy; double xe; double xq; double xw; double xx[8] = { 2.0, 1.0, 0.0, 0.0, 0.0, 1.0, 2.0, 2.0 }; double yn; double yq; double ys; double yy[8] = { 5.0, 5.0, 5.0, 4.0, 3.0, 3.0, 3.0, 4.0 }; cout << "\n"; cout << "TEST02\n"; cout << " Basis function checks.\n"; // // Check that V is identity matrix at nodes. // cout << "\n"; cout << " The matrix Aij = V(j)(X(i),Y(i)) should be the identity.\n"; cout << "\n"; xw = 0.0; ys = 3.0; xe = 2.0; yn = 5.0; for ( i = 0; i < 8; i++ ) { xq = xx[i]; yq = yy[i]; v = basis_serene ( xq, yq, xw, ys, xe, yn, xx, yy ); for ( j = 0; j < 8; j++ ) { cout << setw(10) << v[j]; } cout << "\n"; delete [] v; } // // Check that VX and VY sum to zero anywhere. // cout << "\n"; cout << " The vectors dVdX(1:8)(X,Y) and dVdY(1:8)(X,Y)\n"; cout << " should both sum to zero for any (X,Y).\n"; seed = 123456789; xq = 2.0 * r8_uniform_01 ( seed ); yq = 3.0 + 2.0 * r8_uniform_01 ( seed ); xw = 0.0; ys = 3.0; xe = 2.0; yn = 5.0; vx = basis_dx_serene ( xq, yq, xw, ys, xe, yn, xx, yy ); vy = basis_dy_serene ( xq, yq, xw, ys, xe, yn, xx, yy ); cout << "\n"; cout << " Random evaluation point is (" << xq << "," << yq << ")\n"; cout << "\n"; cout << " dVdX dVdY\n"; cout << "\n"; for ( i = 0; i < 8; i++ ) { cout << setw(6) << i << " " << setw(10) << vx[i] << " " << setw(10) << vy[i] << "\n"; } cout << "\n"; cout << " Sum: " << setw(10) << r8vec_sum ( 8, vx ) << " " << setw(10) << r8vec_sum ( 8, vy ) << "\n"; delete [] vx; delete [] vy; return; } //****************************************************************************80 void test03 ( ) //****************************************************************************80 // // Purpose: // // TEST03 carries out test case #3. // // Discussion: // // Use A3, C3, F3, EXACT3, EXACT_UX3, EXACT_UX3. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // { double *amat; double e1; double e2; double h1s; int i; int inc; int j; int k; int mn; int nx = 5; int ny = 5; double scale; int show11; double *u; double uexact; double *x; double x_first; double x_last; double *y; double y_first; double y_last; cout << "\n"; cout << "TEST03\n"; cout << " Solve - del ( A del U ) + C U = F \n"; cout << " on the unit square with zero boundary conditions.\n"; cout << " A1(X,Y) = 0.0\n"; cout << " C1(X,Y) = 1.0\n"; cout << " F1(X,Y) = X * ( 1 - X ) * Y * ( 1 - Y )\n"; cout << " U1(X,Y) = X * ( 1 - X ) * Y * ( 1 - Y )\n"; cout << "\n"; cout << " This example is contrived so that the system matrix\n"; cout << " is the WATHEN matrix.\n"; cout << "\n"; cout << " Number of X grid values NX = " << nx << "\n"; cout << " Number of Y grid values NY = " << ny << "\n"; mn = nx * ny; // // Geometry definitions. // x_first = 0.0; x_last = 1.0; x = r8vec_linspace_new ( nx, x_first, x_last ); y_first = 0.0; y_last = 1.0; y = r8vec_linspace_new ( ny, y_first, y_last ); show11 = 1; u = fem2d_bvp_serene ( nx, ny, a3, c3, f3, x, y, show11 ); if ( nx * ny <= 25 ) { cout << "\n"; cout << " I J X Y U Uexact Error\n"; cout << "\n"; k = 0; for ( j = 0; j < ny; j++ ) { if ( ( j % 2 ) == 0 ) { inc = 1; } else { inc = 2; } for ( i = 0; i < nx; i = i + inc ) { uexact = exact3 ( x[i], y[j] ); cout << setw(4) << i << " " << setw(4) << j << " " << setw(8) << x[i] << " " << setw(8) << y[j] << " " << setw(14) << u[k] << " " << setw(14) << uexact << " " << setw(14) << fabs ( u[k] - uexact ) << "\n"; k = k + 1; } } } e1 = fem2d_l1_error_serene ( nx, ny, x, y, u, exact3 ); e2 = fem2d_l2_error_serene ( nx, ny, x, y, u, exact3 ); h1s = fem2d_h1s_error_serene ( nx, ny, x, y, u, exact_ux3, exact_uy3 ); cout << "\n"; cout << " l1 norm of error = " << e1 << "\n"; cout << " L2 norm of error = " << e2 << "\n"; cout << " Seminorm of error = " << h1s << "\n"; delete [] u; delete [] x; delete [] y; // // Pull out the Wathen matrix from MATLAB. // It will have been multiplied by a random scale factor. // While my numbering scheme is // 3 2 1 // 4 8 // 5 6 7 // the numbering scheme used here is // 1 2 3 // 4 5 // 6 7 8 // amat = wathen ( 1, 1, 8 ); scale = 0.5 * amat[0+2*8]; for ( j = 0; j < 8; j++ ) { for ( i = 0; i < 8; i++ ) { amat[i+j*8] = amat[i+j*8] / scale; } } r8mat_print ( 8, 8, amat, " Wathen matrix:" ); delete [] amat; return; } //****************************************************************************80 double a3 ( double x, double y ) //****************************************************************************80 // // Purpose: // // A3 evaluates A function #3. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double A3, the value of A(X,Y). // { double value; value = 0.0; return value; } //****************************************************************************80 double c3 ( double x, double y ) //****************************************************************************80 // // Purpose: // // C3 evaluates C function #3. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double C3, the value of C(X,Y). // { double value; value = 1.0; return value; } //****************************************************************************80 double exact3 ( double x, double y ) //****************************************************************************80 // // Purpose: // // EXACT3 evaluates exact solution #3. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double EXACT3, the value of U(X,Y). // { double value; value = x * ( 1.0 - x ) * y * ( 1.0 - y ); return value; } //****************************************************************************80 double exact_ux3 ( double x, double y ) //****************************************************************************80 // // Purpose: // // EXACT_UX3 evaluates the derivative of exact solution #3. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double EXACT_UX3, the value of dUdX(X,Y). // { double value; value = ( 1.0 - 2.0 * x ) * ( y - y * y ); return value; } //****************************************************************************80 double exact_uy3 ( double x, double y ) //****************************************************************************80 // // Purpose: // // EXACT_UY3 evaluates the derivative of exact solution #3. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double EXACT_UY3, the value of dUdY(X,Y). // { double value; value = ( x - x * x ) * ( 1.0 - 2.0 * y ); return value; } //****************************************************************************80 double f3 ( double x, double y ) //****************************************************************************80 // // Purpose: // // F3 evaluates right hand side function #3. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 07 July 2014 // // Author: // // John Burkardt // // Parameters: // // Input, double X, Y, the evaluation point. // // Output, double F3, the value of F(X,Y). // { double value; value = x * ( 1.0 - x ) * y * ( 1.0 - y ); return value; }