private static void test05() //****************************************************************************80 // // Purpose: // // TEST05 demonstrates REFERENCE_TO_PHYSICAL_T3. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 30 January 2007 // // Author: // // John Burkardt // { const int NODE_NUM = 3; int node; double[] node_xy = { 0.0, 0.0, 1.0, 0.0, 0.0, 1.0 }; double[] node_xy2 = { 1.0, 2.0, 1.0, 1.0, 3.0, 2.0 }; int order; Console.WriteLine(""); Console.WriteLine("TEST05"); Console.WriteLine(" REFERENCE_TO_PHYSICAL_T3 transforms a rule"); Console.WriteLine(" on the unit (reference) triangle to a rule on "); Console.WriteLine(" an arbitrary (physical) triangle."); const int rule = 3; int order_num = NewtonCotesClosed.triangle_ncc_order_num(rule); double[] xy = new double[2 * order_num]; double[] xy2 = new double[2 * order_num]; double[] w = new double[order_num]; NewtonCotesClosed.triangle_ncc_rule(rule, order_num, ref xy, ref w); // // Here is the reference triangle, and its rule. // Console.WriteLine(""); Console.WriteLine(" The reference triangle:"); Console.WriteLine(""); for (node = 0; node < NODE_NUM; node++) { Console.WriteLine(" " + node + 1 + " " + node_xy[0 + node * 2] + " " + node_xy[1 + node * 2] + ""); } double area = Integrals.triangle_area(node_xy); Console.WriteLine(""); Console.WriteLine(" Rule " + rule + " for reference triangle"); Console.WriteLine(" with area = " + area + ""); Console.WriteLine(""); Console.WriteLine(" X Y W"); Console.WriteLine(""); for (order = 0; order < order_num; order++) { Console.WriteLine(" " + order.ToString(CultureInfo.InvariantCulture).PadLeft(8) + " " + xy[0 + order * 2].ToString(CultureInfo.InvariantCulture).PadLeft(14) + " " + xy[1 + order * 2].ToString(CultureInfo.InvariantCulture).PadLeft(14) + " " + w[order].ToString(CultureInfo.InvariantCulture).PadLeft(14) + ""); } // // Transform the rule. // Reference.reference_to_physical_t3(node_xy2, order_num, xy, ref xy2); // // Here is the physical triangle, and its transformed rule. // Console.WriteLine(""); Console.WriteLine(" The physical triangle:"); Console.WriteLine(""); for (node = 0; node < NODE_NUM; node++) { Console.WriteLine(" " + (node + 1).ToString(CultureInfo.InvariantCulture).PadLeft(8) + " " + node_xy2[0 + node * 2].ToString(CultureInfo.InvariantCulture).PadLeft(14) + " " + node_xy2[1 + node * 2].ToString(CultureInfo.InvariantCulture).PadLeft(14) + ""); } double area2 = Integrals.triangle_area(node_xy2); Console.WriteLine(""); Console.WriteLine(" Rule " + rule + " for physical triangle"); Console.WriteLine(" with area = " + area2 + ""); Console.WriteLine(""); Console.WriteLine(" X Y W"); Console.WriteLine(""); for (order = 0; order < order_num; order++) { Console.WriteLine(" " + order.ToString(CultureInfo.InvariantCulture).PadLeft(8) + " " + xy2[0 + order * 2].ToString(CultureInfo.InvariantCulture).PadLeft(14) + " " + xy2[1 + order * 2].ToString(CultureInfo.InvariantCulture).PadLeft(14) + " " + w[order].ToString(CultureInfo.InvariantCulture).PadLeft(14) + ""); } }
private static void test02() //****************************************************************************80 // // Purpose: // // TEST02 tests TRIANGLE_NCC_RULE. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 30 January 2007 // // Author: // // John Burkardt // { int rule; Console.WriteLine(""); Console.WriteLine("TEST02"); Console.WriteLine(" TRIANGLE_NCC_RULE returns the points and weights"); Console.WriteLine(" of an NCC rule for the triangle."); Console.WriteLine(""); Console.WriteLine(" In this test, we simply check that the weights"); Console.WriteLine(" sum to 1."); int rule_num = NewtonCotesClosed.triangle_ncc_rule_num(); Console.WriteLine(""); Console.WriteLine(" Number of available rules = " + rule_num + ""); Console.WriteLine(""); Console.WriteLine(" Rule Order Sum of weights"); Console.WriteLine(""); for (rule = 1; rule <= rule_num; rule++) { int order_num = NewtonCotesClosed.triangle_ncc_order_num(rule); double[] xytab = new double[2 * order_num]; double[] wtab = new double[order_num]; NewtonCotesClosed.triangle_ncc_rule(rule, order_num, ref xytab, ref wtab); double wtab_sum = 0.0; int order; for (order = 0; order < order_num; order++) { wtab_sum += wtab[order]; } Console.WriteLine(" " + rule.ToString(CultureInfo.InvariantCulture).PadLeft(8) + " " + order_num.ToString(CultureInfo.InvariantCulture).PadLeft(8) + " " + wtab_sum.ToString(CultureInfo.InvariantCulture).PadLeft(14) + ""); } }
private static void test04() //****************************************************************************80 // // Purpose: // // TEST04 tests TRIANGLE_NCC_RULE. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 30 January 2007 // // Author: // // John Burkardt // { int a; const double area = 0.5; double value = 0; Console.WriteLine(""); Console.WriteLine("TEST04"); Console.WriteLine(" TRIANGLE_NCC_RULE returns the points and weights of"); Console.WriteLine(" an NCC rule for the unit triangle."); Console.WriteLine(""); Console.WriteLine(" This routine uses those rules to estimate the"); Console.WriteLine(" integral of monomomials in the unit triangle."); int rule_num = NewtonCotesClosed.triangle_ncc_rule_num(); for (a = 0; a <= 10; a++) { int b; for (b = 0; b <= 10 - a; b++) { // // Multiplying X^A * Y^B by COEF will give us an integrand // whose integral is exactly 1. This makes the error calculations easy. // double coef = (a + b + 2) * (double)(a + b + 1); int i; for (i = 1; i <= b; i++) { coef = coef * (a + i) / i; } Console.WriteLine(""); Console.WriteLine(" Integrate " + coef + " * X^" + a + " * Y^" + b + ""); Console.WriteLine(""); Console.WriteLine(" Rule QUAD ERROR"); Console.WriteLine(""); int rule; for (rule = 1; rule <= rule_num; rule++) { int order_num = NewtonCotesClosed.triangle_ncc_order_num(rule); double[] xytab = new double[2 * order_num]; double[] wtab = new double[order_num]; NewtonCotesClosed.triangle_ncc_rule(rule, order_num, ref xytab, ref wtab); double quad = 0.0; int order; for (order = 0; order < order_num; order++) { double x = xytab[0 + order * 2]; double y = xytab[1 + order * 2]; switch (a) { case 0 when b == 0: value = coef; break; case 0 when b != 0: value = coef * Math.Pow(y, b); break; default: { if (a != 0 && b == 0) { value = coef * Math.Pow(x, a); } else if (a != 0 && b != 0) { value = coef * Math.Pow(x, a) * Math.Pow(y, b); } break; } } quad += wtab[order] * value; } quad = area * quad; double exact = 1.0; double err = Math.Abs(exact - quad); Console.WriteLine(" " + rule.ToString(CultureInfo.InvariantCulture).PadLeft(8) + " " + quad.ToString(CultureInfo.InvariantCulture).PadLeft(14) + " " + err.ToString(CultureInfo.InvariantCulture).PadLeft(14) + ""); } } } }