private static void test02()
//****************************************************************************80
//
// Purpose:
//
// TEST02 examines the sample points in the pyramid
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 14 April 2014
//
// Author:
//
// John Burkardt
//
{
const int n = 20;
Console.WriteLine("");
Console.WriteLine("TEST02");
Console.WriteLine(" Print sample points in the unit pyramid in 3D.");
int seed = 123456789;
double[] x = Integrals.pyramid01_sample(n, ref seed);
typeMethods.r8mat_transpose_print(3, n, x, " Unit pyramid points");
}
public void RectangularInfititeTest()
{
var integral = new Integral(t => Pow(E, -t), 0, double.PositiveInfinity);
var result = Integrals.RectangularInfinite(integral, 100000, 10);
Assert.That(result, Is.EqualTo(1).Within(0.0001));
}
public virtual double HCoeffs(int s)
{
// TODO: use Gauss quadrature formula
var coeffSym = mathlib.ScalarMul.LebesgueLaguerre(_right, Laguerre.Get(s));
return(Integrals.RectangularInfinite(coeffSym, 100000, 10));
}
/// <summary>
/// Calculates $c_k(f_j)$
/// </summary>
/// <param name="i"></param>
/// <param name="k"></param>
/// <param name="fArgs"></param>
/// <returns></returns>
private double CalcCoeff(int i, int k, double[][] fArgs)
{
// qk[j] = $f_k(h t_j, \eta_0(t_j), ..., \eta_{m-1}(t_j)) * phi_k(t_j)$,
// so qk is a vector of values of function $q_k(t)=f_k(ht,\eta_0(t),...) phi(t)$ in _nodes
var qk = _nodes.Select((t, j) => _f[i].Invoke(fArgs[j]) * _phiCached[k](t));
return(Integrals.Trapezoid(qk.ToArray(), _nodes));
}
private static void test01()
//****************************************************************************80
//
// Purpose:
//
// TEST01 compares exact and estimated monomial integrals.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 18 January 2014
//
// Author:
//
// John Burkardt
//
{
const int n = 4192;
int test;
const int test_num = 11;
Console.WriteLine("");
Console.WriteLine("TEST01");
Console.WriteLine(" Compare exact and estimated integrals ");
Console.WriteLine(" over the length of the unit line in 1D.");
//
// Get sample points.
//
int seed = 123456789;
double[] x = Integrals.line01_sample(n, ref seed);
Console.WriteLine("");
Console.WriteLine(" Number of sample points used is " + n + "");
Console.WriteLine("");
Console.WriteLine(" E MC-Estimate Exact Error");
Console.WriteLine("");
for (test = 1; test <= test_num; test++)
{
int e = test - 1;
double[] value = Monomial.monomial_value_1d(n, e, x);
double result = Integrals.line01_length() * typeMethods.r8vec_sum(n, value) / n;
double exact = Integrals.line01_monomial_integral(e);
double error = Math.Abs(result - exact);
Console.WriteLine(" " + e.ToString(CultureInfo.InvariantCulture).PadLeft(2)
+ " " + result.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + exact.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + error.ToString(CultureInfo.InvariantCulture).PadLeft(10) + "");
}
}
public static double sphere01_monomial_quadrature(int[] expon, int point_num, double[] xyz,
double[] w)
//****************************************************************************80
//
// Purpose:
//
// SPHERE01_MONOMIAL_QUADRATURE applies quadrature to a monomial in a sphere.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 05 July 2007
//
// Author:
//
// John Burkardt
//
// Parameters:
//
// Input, int DIM_NUM, the spatial dimension.
//
// Input, int EXPON[DIM_NUM], the exponents.
//
// Input, int POINT_NUM, the number of points in the rule.
//
// Input, double XYZ[DIM_NUM*POINT_NUM], the quadrature points.
//
// Input, double W[POINT_NUM], the quadrature weights.
//
// Output, double SPHERE01_MONOMIAL_QUADRATURE, the quadrature error.
//
{
//
// Get the exact value of the integral.
//
double exact = Integrals.sphere01_monomial_integral(expon);
//
// Evaluate the monomial at the quadrature points.
//
double[] value = MonomialNS.Monomial.monomial_value(3, point_num, expon, xyz);
//
// Compute the weighted sum.
//
double quad = typeMethods.r8vec_dot(point_num, w, value);
//
// Error:
//
double quad_error = Math.Abs(quad - exact);
return(quad_error);
}
public void TrapezoidDiscreteTest()
{
RunTestCases(
testCase =>
{
var nodes = GenerateNodes(testCase.A, testCase.B, testCase.NodesCount);
var fD = nodes.Select(t => testCase.Func(t)).ToArray();
return(Integrals.Trapezoid(fD, nodes));
});
}
private static void test11()
//****************************************************************************
//
// Purpose:
//
// TEST11 tests STOCHASTIC_INTEGRAL_STRAT.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 28 September 2012
//
// Author:
//
// John Burkardt
//
{
double error = 0;
double estimate = 0;
double exact = 0;
int i;
Console.WriteLine("");
Console.WriteLine("TEST11:");
Console.WriteLine(" Estimate the Stratonovich integral of W(t) dW over [0,1].");
Console.WriteLine("");
Console.WriteLine(" Abs Rel");
Console.WriteLine(" N Exact Estimate Error Error");
Console.WriteLine("");
int n = 100;
int seed = 123456789;
typeMethods.r8vecNormalData data = new();
for (i = 1; i <= 7; i++)
{
Integrals.stochastic_integral_strat(n, ref data, ref seed, ref estimate, ref exact, ref error);
Console.WriteLine(" " + n.ToString().PadLeft(8)
+ " " + exact.ToString(CultureInfo.InvariantCulture).PadLeft(16)
+ " " + estimate.ToString(CultureInfo.InvariantCulture).PadLeft(16)
+ " " + error.ToString(CultureInfo.InvariantCulture).PadLeft(16)
+ " " + (error / exact).ToString(CultureInfo.InvariantCulture).PadLeft(16) + "");
n *= 4;
}
}
public void ShouldSuccessCalculateIntegralViaMidRectMethod(double a, double b, int n, double expectedResult, double eps)
{
IntegrateOptions options = new IntegrateOptions()
{
StartX = a,
EndX = b,
Steps = n,
Function = TestFunc
};
double actualResult = Integrals.MidRect(options);
Assert.IsTrue(Math.Abs(expectedResult - actualResult) <= eps);
}
static void Main(string[] args)
{
double a = -1, b = 0.9;
int n = 100;
IntegrateOptions options = new IntegrateOptions()
{
StartX = a,
EndX = b,
Steps = n,
Function = x => 20 * x - 2.5 / (x - 1)
};
double S = Integrals.MidRect(options);
Console.WriteLine("Result {0:#.###E+00}", S);
}
public void CosSytemOrthonormality()
{
var cosSystem = new CosSystem();
for (int i = 0; i < 100; i++)
{
var i1 = i;
var v = Integrals.Trapezoid(x => cosSystem.Get(i1)(x) * cosSystem.Get(i1)(x), 0, 1, 10000);
Assert.AreEqual(1, v, 0.0000001);
}
var val = Integrals.Trapezoid(x => cosSystem.Get(0)(x) * cosSystem.Get(5)(x), 0, 1, 10000);
Assert.AreEqual(0, val, 0.0000001);
val = Integrals.Trapezoid(x => cosSystem.Get(4)(x) * cosSystem.Get(5)(x), 0, 1, 10000);
Assert.AreEqual(0, val, 0.0000001);
}
public static Func <double, double> Get(int n)
{
double One(double x) => 1;
if (n == 0)
{
return(One);
}
var nodesCount = (int)Math.Pow(2, (int)Math.Ceiling(Math.Log(n, 2)) + 6);
var nodes = Enumerable.Range(0, nodesCount).Select(j => j * 1.0 / nodesCount);
double Sobolev(double x)
{
return(Integrals.Rectangular(Walsh.Get(n - 1), nodes.Where(node => node <= x).ToArray(),
Integrals.RectType.Center));
}
return(Sobolev);
}
private static void Main()
//****************************************************************************80
//
// Purpose:
//
// MAIN is the main program for CUBE_FELIPPA_RULE_TEST.
//
// Discussion:
//
// CUBE_FELIPPA_RULE_TEST tests the CUBE_FELIPPA_RULE library.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 05 September 2014
//
// Author:
//
// John Burkardt
//
{
Console.WriteLine("");
Console.WriteLine("CUBE_FELIPPA_RULE_TEST");
Console.WriteLine(" Test the CUBE_FELIPPA_RULE library.");
int degree_max = 4;
Integrals.cube_monomial_test(degree_max);
degree_max = 6;
QuadratureRule.cube_quad_test(degree_max);
Console.WriteLine("");
Console.WriteLine("CUBE_FELIPPA_RULE_TEST");
Console.WriteLine(" Normal end of execution.");
Console.WriteLine("");
}
private static void triangle_area_test()
//****************************************************************************80
//
// Purpose:
//
// TRIANGLE_AREA_TEST tests TRIANGLE_AREA.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 04 November 2015
//
// Author:
//
// John Burkardt
//
{
double[] t =
{
0.0, 1.0,
0.0, 0.0,
1.0, 0.0
};
Console.WriteLine("");
Console.WriteLine("TRIANGLE_AREA_TEST");
Console.WriteLine(" TRIANGLE_AREA computes the area of a triangle.");
typeMethods.r8mat_transpose_print(2, 3, t, " Triangle vertices:");
double area = Integrals.triangle_area(t);
Console.WriteLine("");
Console.WriteLine(" Triangle area is " + area + "");
}
private static void test05(ref int[] e_save)
//****************************************************************************80
//
// Purpose:
//
// TEST05 tests SPHERE01_QUAD_ICOS2V.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 24 September 2010
//
// Author:
//
// John Burkardt
//
{
int[] e = new int[3];
int i;
int n = 0;
Console.WriteLine("");
Console.WriteLine("TEST05");
Console.WriteLine(" Approximate the integral of a function on the unit sphere.");
Console.WriteLine(" SPHERE01_QUAD_ICOS2V uses vertices of spherical triangles.");
Console.WriteLine("");
Console.WriteLine("FACTOR N QUAD EXACT ERROR");
for (i = 1; i <= 17; i++)
{
switch (i)
{
case 1:
e[0] = 0;
e[1] = 0;
e[2] = 0;
break;
case 2:
e[0] = 1;
e[1] = 0;
e[2] = 0;
break;
case 3:
e[0] = 0;
e[1] = 1;
e[2] = 0;
break;
case 4:
e[0] = 0;
e[1] = 0;
e[2] = 1;
break;
case 5:
e[0] = 2;
e[1] = 0;
e[2] = 0;
break;
case 6:
e[0] = 0;
e[1] = 2;
e[2] = 2;
break;
case 7:
e[0] = 2;
e[1] = 2;
e[2] = 2;
break;
case 8:
e[0] = 0;
e[1] = 2;
e[2] = 4;
break;
case 9:
e[0] = 0;
e[1] = 0;
e[2] = 6;
break;
case 10:
e[0] = 1;
e[1] = 2;
e[2] = 4;
break;
case 11:
e[0] = 2;
e[1] = 4;
e[2] = 2;
break;
case 12:
e[0] = 6;
e[1] = 2;
e[2] = 0;
break;
case 13:
e[0] = 0;
e[1] = 0;
e[2] = 8;
break;
case 14:
e[0] = 6;
e[1] = 0;
e[2] = 4;
break;
case 15:
e[0] = 4;
e[1] = 6;
e[2] = 2;
break;
case 16:
e[0] = 2;
e[1] = 4;
e[2] = 8;
break;
case 17:
e[0] = 16;
e[1] = 0;
e[2] = 0;
break;
}
polyterm_exponent("SET", ref e_save, ref e);
polyterm_exponent("PRINT", ref e_save, ref e);
int factor = 1;
int factor_log;
for (factor_log = 0; factor_log <= 5; factor_log++)
{
double result = Quad.sphere01_quad_icos2v(factor, polyterm_value_3d, ref n);
double exact = Integrals.sphere01_monomial_integral(e);
double error = Math.Abs(exact - result);
Console.WriteLine(" " + factor.ToString().PadLeft(4)
+ " " + n.ToString().PadLeft(8)
+ " " + result.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + exact.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + error.ToString(CultureInfo.InvariantCulture).PadLeft(14) + "");
factor *= 2;
}
}
}
private static void test01(ref int[] e_save)
//****************************************************************************80
//
// Purpose:
//
// TEST01 tests SPHERE01_QUAD_LL*.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 25 September 2010
//
// Author:
//
// John Burkardt
//
{
int[] e = new int[3];
double h = 0;
int i;
int n_llc = 0;
int n_llm = 0;
int n_llv = 0;
int seed = 123456789;
Console.WriteLine("");
Console.WriteLine("TEST01");
Console.WriteLine(" Approximate the integral of a function on the unit sphere.");
Console.WriteLine("");
Console.WriteLine(" SPHERE01_QUAD_MC uses a Monte Carlo method.");
Console.WriteLine(" SPHERE01_QUAD_LLC uses centroids of spherical triangles.");
Console.WriteLine(" SPHERE01_QUAD_LLM uses midsides of spherical triangles.");
Console.WriteLine(" SPHERE01_QUAD_LLV uses vertices of spherical triangles.");
Console.WriteLine("");
Console.WriteLine(" H QUAD_MC QUAD_LLC QUAD_LLM QUAD_LLV EXACT");
for (i = 0; i <= 17; i++)
{
switch (i)
{
case 0:
e[0] = 0;
e[1] = 0;
e[2] = 0;
break;
case 1:
e[0] = 0;
e[1] = 0;
e[2] = 0;
break;
case 2:
e[0] = 1;
e[1] = 0;
e[2] = 0;
break;
case 3:
e[0] = 0;
e[1] = 1;
e[2] = 0;
break;
case 4:
e[0] = 0;
e[1] = 0;
e[2] = 1;
break;
case 5:
e[0] = 2;
e[1] = 0;
e[2] = 0;
break;
case 6:
e[0] = 0;
e[1] = 2;
e[2] = 2;
break;
case 7:
e[0] = 2;
e[1] = 2;
e[2] = 2;
break;
case 8:
e[0] = 0;
e[1] = 2;
e[2] = 4;
break;
case 9:
e[0] = 0;
e[1] = 0;
e[2] = 6;
break;
case 10:
e[0] = 1;
e[1] = 2;
e[2] = 4;
break;
case 11:
e[0] = 2;
e[1] = 4;
e[2] = 2;
break;
case 12:
e[0] = 6;
e[1] = 2;
e[2] = 0;
break;
case 13:
e[0] = 0;
e[1] = 0;
e[2] = 8;
break;
case 14:
e[0] = 6;
e[1] = 0;
e[2] = 4;
break;
case 15:
e[0] = 4;
e[1] = 6;
e[2] = 2;
break;
case 16:
e[0] = 2;
e[1] = 4;
e[2] = 8;
break;
case 17:
e[0] = 16;
e[1] = 0;
e[2] = 0;
break;
}
polyterm_exponent("SET", ref e_save, ref e);
switch (i)
{
case 0:
Console.WriteLine("");
Console.WriteLine("Point counts per method:");
break;
default:
polyterm_exponent("PRINT", ref e_save, ref e);
break;
}
int h_test;
for (h_test = 1; h_test <= 3; h_test++)
{
h = h_test switch
{
1 => 1.0,
2 => 0.1,
3 => 0.01,
_ => h
};
int n_mc = Quad.sphere01_quad_mc_size(h);
double result_mc = Quad.sphere01_quad_mc(polyterm_value_3d, h, ref seed, n_mc);
double result_llc = Quad.sphere01_quad_llc(polyterm_value_3d, h, ref n_llc);
double result_llm = Quad.sphere01_quad_llm(polyterm_value_3d, h, ref n_llm);
double result_llv = Quad.sphere01_quad_llv(polyterm_value_3d, h, ref n_llv);
double exact = Integrals.sphere01_monomial_integral(e);
switch (i)
{
case 0:
Console.WriteLine(" " + h.ToString(CultureInfo.InvariantCulture).PadLeft(12)
+ " " + n_mc.ToString().PadLeft(12)
+ " " + n_llc.ToString().PadLeft(12)
+ " " + n_llm.ToString().PadLeft(12)
+ " " + n_llv.ToString().PadLeft(12) + "");
break;
default:
Console.WriteLine(" " + h.ToString(CultureInfo.InvariantCulture).PadLeft(12)
+ " " + result_mc.ToString(CultureInfo.InvariantCulture).PadLeft(12)
+ " " + result_llc.ToString(CultureInfo.InvariantCulture).PadLeft(12)
+ " " + result_llm.ToString(CultureInfo.InvariantCulture).PadLeft(12)
+ " " + result_llv.ToString(CultureInfo.InvariantCulture).PadLeft(12)
+ " " + exact.ToString(CultureInfo.InvariantCulture).PadLeft(12) + "");
break;
}
}
}
}
private static void test01()
//****************************************************************************80
//
// Purpose:
//
// TEST01 estimates integrals over the unit cube in 3D.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 19 January 2014
//
// Author:
//
// John Burkardt
//
{
const int m = 3;
const int n = 4192;
int test;
const int test_num = 20;
Console.WriteLine("");
Console.WriteLine("TEST01");
Console.WriteLine(" Compare exact and estimated integrals");
Console.WriteLine(" over the interior of the unit cube in 3D.");
//
// Get sample points.
//
int seed = 123456789;
double[] x = Integrals.cube01_sample(n, ref seed);
Console.WriteLine("");
Console.WriteLine(" Number of sample points is " + n + "");
//
// Randomly choose exponents.
//
Console.WriteLine("");
Console.WriteLine(" Ex Ey Ez MC-Estimate Exact Error");
Console.WriteLine("");
for (test = 1; test <= test_num; test++)
{
int[] e = UniformRNG.i4vec_uniform_ab_new(m, 0, 7, ref seed);
double[] value = Monomial.monomial_value(m, n, e, x);
double result = Integrals.cube01_volume() * typeMethods.r8vec_sum(n, value) / n;
double exact = Integrals.cube01_monomial_integral(e);
double error = Math.Abs(result - exact);
Console.WriteLine(" " + e[0].ToString(CultureInfo.InvariantCulture).PadLeft(2)
+ " " + e[1].ToString(CultureInfo.InvariantCulture).PadLeft(2)
+ " " + e[2].ToString(CultureInfo.InvariantCulture).PadLeft(2)
+ " " + result.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + exact.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + error.ToString(CultureInfo.InvariantCulture).PadLeft(14) + "");
}
}
public void TrapezoidEquiDistantNetTest()
{
RunTestCases(
testCase => Integrals.Trapezoid(testCase.Func, testCase.A, testCase.B, testCase.NodesCount)
);
}
private static void square01_monomial_integral_test()
//****************************************************************************80
//
// Purpose:
//
// SQUARE01_MONOMIAL_INTEGRAL_TEST tests SQUARE01_MONOMIAL_INTEGRAL.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 21 February 2018
//
// Author:
//
// John Burkardt
//
{
const int m = 2;
const int n = 4192;
int test;
const int test_num = 20;
Console.WriteLine("");
Console.WriteLine("SQUARE01_MONOMIAL_INTEGRAL_TEST");
Console.WriteLine(" SQUARE01_MONOMIAL_INTEGRAL returns the exact integral");
Console.WriteLine(" of a monomial over the interior of the unit square in 2D.");
Console.WriteLine(" Compare exact and estimated values.");
//
// Get sample points.
//
int seed = 123456789;
double[] x = Integrals.square01_sample(n, ref seed);
Console.WriteLine("");
Console.WriteLine(" Number of sample points is " + n + "");
//
// Randomly choose exponents.
//
Console.WriteLine("");
Console.WriteLine(" Ex Ey MC-Estimate Exact Error");
Console.WriteLine("");
for (test = 1; test <= test_num; test++)
{
int[] e = UniformRNG.i4vec_uniform_ab_new(m, 0, 7, ref seed);
double[] value = Monomial.monomial_value(m, n, e, x);
double result = Integrals.square01_area() * typeMethods.r8vec_sum(n, value) / n;
double exact = Integrals.square01_monomial_integral(e);
double error = Math.Abs(result - exact);
Console.WriteLine(" " + e[0].ToString().PadLeft(2)
+ " " + e[1].ToString().PadLeft(2)
+ " " + result.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + exact.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + error.ToString(CultureInfo.InvariantCulture).PadLeft(14) + "");
}
}
public static double square_minimal_rule_error_max(int degree)
//****************************************************************************80
//
// Purpose:
//
// SQUARE_MINIMAL_RULE_ERROR_MAX returns the maximum error.
//
// Discussion:
//
// The rule of given DEGREE should theoretically have zero error
// for all monomials of degrees 0 <= D <= DEGREE. This function
// checks every such monomial and reports the maximum error.
//
// Licensing:
//
// This code is distributed under the GNU GPL license.
//
// Modified:
//
// 22 February 2018
//
// Author:
//
// John Burkardt.
//
// Reference:
//
// Mattia Festa, Alvise Sommariva,
// Computing almost minimal formulas on the square,
// Journal of Computational and Applied Mathematics,
// Volume 17, Number 236, November 2012, pages 4296-4302.
//
// Parameters:
//
// Input, int DEGREE, the desired total polynomial degree exactness
// of the quadrature rule.
//
// Output, double SQUARE_MINIMAL_RULE_ERROR_MAX, the maximum error observed
// when using the rule to compute the integrals of all monomials of degree
// between 0 and DEGREE.
//
{
int d;
int[] e = new int[2];
int order = square_minimal_rule_order(degree);
double[] xyw = square_minimal_rule(degree);
double error_max = 0.0;
for (d = 0; d <= degree; d++)
{
int i;
for (i = 0; i <= d; i++)
{
int j = d - i;
e[0] = i;
e[1] = j;
double exact = Integrals.squaresym_monomial_integral(e);
double s = 0.0;
int k;
for (k = 0; k < order; k++)
{
s += xyw[2 + k * 3] * Math.Pow(xyw[0 + k * 3], i) * Math.Pow(xyw[1 + k * 3], j);
}
double err = Math.Abs(exact - s);
if (error_max < err)
{
error_max = err;
}
}
}
return(error_max);
}
private static void Main(string[] args)
//****************************************************************************80
//
// Purpose:
//
// MAIN is the main program for TRIANGLE_EXACTNESS.
//
// Discussion:
//
// This program investigates the polynomial exactness of a quadrature
// rule for the triangle.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 31 July 2009
//
// Author:
//
// John Burkardt
//
{
int degree;
int degree_max;
bool error = false;
int last = 0;
int point;
string quad_filename;
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS");
Console.WriteLine("");
Console.WriteLine(" Investigate the polynomial exactness of a quadrature");
Console.WriteLine(" rule for the triangle by integrating all monomials");
Console.WriteLine(" of a given degree.");
Console.WriteLine("");
Console.WriteLine(" The rule will be adjusted to the unit triangle.");
//
// Get the quadrature file root name:
//
try
{
quad_filename = args[0];
}
catch
{
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS:");
Console.WriteLine(" Enter the \"root\" name of the quadrature files.");
quad_filename = Console.ReadLine();
}
//
// Create the names of:
// the quadrature X file;
// the quadrature W file;
// the quadrature R file;
//
string quad_r_filename = quad_filename + "_r.txt";
string quad_w_filename = quad_filename + "_w.txt";
string quad_x_filename = quad_filename + "_x.txt";
//
// The second command line argument is the maximum degree.
//
try
{
degree_max = typeMethods.s_to_i4(args[1], ref last, ref error);
}
catch
{
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS:");
Console.WriteLine(" Please enter the maximum total degree to check.");
degree_max = Convert.ToInt32(Console.ReadLine());
}
//
// Summarize the input.
//
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS: User input:");
Console.WriteLine(" Quadrature rule X file = \"" + quad_x_filename
+ "\".");
Console.WriteLine(" Quadrature rule W file = \"" + quad_w_filename
+ "\".");
Console.WriteLine(" Quadrature rule R file = \"" + quad_r_filename
+ "\".");
Console.WriteLine(" Maximum total degree to check = " + degree_max + "");
//
// Read the X file.
//
TableHeader hdr = typeMethods.r8mat_header_read(quad_x_filename);
int dim_num = hdr.m;
int point_num = hdr.n;
Console.WriteLine("");
Console.WriteLine(" Spatial dimension = " + dim_num + "");
Console.WriteLine(" Number of points = " + point_num + "");
if (dim_num != 2)
{
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS - Fatal error!");
Console.WriteLine(" The quadrature abscissas must be two dimensional.");
return;
}
double[] x = typeMethods.r8mat_data_read(quad_x_filename, dim_num, point_num);
//
// Read the W file.
//
hdr = typeMethods.r8mat_header_read(quad_w_filename);
int dim_num2 = hdr.m;
int point_num2 = hdr.n;
if (dim_num2 != 1)
{
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS - Fatal error!");
Console.WriteLine(" The quadrature weight file should have exactly");
Console.WriteLine(" one value on each line.");
return;
}
if (point_num2 != point_num)
{
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS - Fatal error!");
Console.WriteLine(" The quadrature weight file should have exactly");
Console.WriteLine(" the same number of lines as the abscissa file.");
return;
}
double[] w = typeMethods.r8mat_data_read(quad_w_filename, 1, point_num);
//
// Read the R file.
//
hdr = typeMethods.r8mat_header_read(quad_r_filename);
int dim_num3 = hdr.m;
int point_num3 = hdr.n;
if (dim_num3 != dim_num)
{
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS - Fatal error!");
Console.WriteLine(" The quadrature region file should have the same");
Console.WriteLine(" number of values on each line as the abscissa file");
Console.WriteLine(" does.");
return;
}
if (point_num3 != 3)
{
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS - Fatal error!");
Console.WriteLine(" The quadrature region file should have 3 lines.");
return;
}
double[] r = typeMethods.r8mat_data_read(quad_r_filename, dim_num, 3);
//
// Rescale the weights.
//
double area = Integrals.triangle_area(r);
for (point = 0; point < point_num; point++)
{
w[point] = 0.5 * w[point] / area;
}
//
// Translate the abscissas.
//
double[] x_ref = new double[2 * point_num];
Triangulation.triangle_order3_physical_to_reference(r, point_num, x, ref x_ref);
//
// Explore the monomials.
//
int[] expon = new int[dim_num];
Console.WriteLine("");
Console.WriteLine(" Error Degree Exponents");
for (degree = 0; degree <= degree_max; degree++)
{
Console.WriteLine("");
bool more = false;
int h = 0;
int t = 0;
for (;;)
{
Comp.comp_next(degree, dim_num, ref expon, ref more, ref h, ref t);
double quad_error = Integrals.triangle01_monomial_quadrature(dim_num, expon, point_num,
x_ref, w);
string cout = " " + quad_error.ToString(CultureInfo.InvariantCulture).PadLeft(12)
+ " " + degree.ToString().PadLeft(2)
+ " ";
int dim;
for (dim = 0; dim < dim_num; dim++)
{
cout += expon[dim].ToString().PadLeft(3);
}
Console.WriteLine(cout);
if (!more)
{
break;
}
}
}
Console.WriteLine("");
Console.WriteLine("TRIANGLE_EXACTNESS:");
Console.WriteLine(" Normal end of execution.");
Console.WriteLine("");
}
public static double[] sample_quad_new(double[] quad_xy, int n, ref int seed)
//****************************************************************************80
//
// Purpose:
//
// SAMPLE_QUAD_NEW returns random points in a quadrilateral.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 22 February 2009
//
// Author:
//
// John Burkardt
//
// Parameters:
//
// Input, double QUAD_XY[2*4], the coordinates of the nodes.
//
// Input, int N, the number of points to sample.
//
// Input/output, int *SEED, a seed for the random
// number generator.
//
// Output, double SAMPLE_QUAD[2*N], the sample points.
//
{
int i;
double[] t1 = new double[2 * 3];
double[] t2 = new double[2 * 3];
t1[0 + 0 * 2] = quad_xy[0 + 0 * 2];
t1[1 + 0 * 2] = quad_xy[1 + 0 * 2];
t1[0 + 1 * 2] = quad_xy[0 + 1 * 2];
t1[1 + 1 * 2] = quad_xy[1 + 1 * 2];
t1[0 + 2 * 2] = quad_xy[0 + 2 * 2];
t1[1 + 2 * 2] = quad_xy[1 + 2 * 2];
double area1 = Integrals.triangle_area(t1);
t2[0 + 0 * 2] = quad_xy[0 + 2 * 2];
t2[1 + 0 * 2] = quad_xy[1 + 2 * 2];
t2[0 + 1 * 2] = quad_xy[0 + 3 * 2];
t2[1 + 1 * 2] = quad_xy[1 + 3 * 2];
t2[0 + 2 * 2] = quad_xy[0 + 0 * 2];
t2[1 + 2 * 2] = quad_xy[1 + 0 * 2];
double area2 = Integrals.triangle_area(t2);
if (area1 < 0.0 || area2 < 0.0)
{
t1[0 + 0 * 2] = quad_xy[0 + 1 * 2];
t1[1 + 0 * 2] = quad_xy[1 + 1 * 2];
t1[0 + 1 * 2] = quad_xy[0 + 2 * 2];
t1[1 + 1 * 2] = quad_xy[1 + 2 * 2];
t1[0 + 2 * 2] = quad_xy[0 + 3 * 2];
t1[1 + 2 * 2] = quad_xy[1 + 3 * 2];
area1 = Integrals.triangle_area(t1);
t2[0 + 0 * 2] = quad_xy[0 + 3 * 2];
t2[1 + 0 * 2] = quad_xy[1 + 3 * 2];
t2[0 + 1 * 2] = quad_xy[0 + 0 * 2];
t2[1 + 1 * 2] = quad_xy[1 + 0 * 2];
t2[0 + 2 * 2] = quad_xy[0 + 1 * 2];
t2[1 + 2 * 2] = quad_xy[1 + 1 * 2];
area2 = Integrals.triangle_area(t2);
if (area1 < 0.0 || area2 < 0.0)
{
Console.WriteLine("");
Console.WriteLine("SAMPLE_QUAD - Fatal error!");
Console.WriteLine(" The quadrilateral nodes seem to be listed in");
Console.WriteLine(" the wrong order, or the quadrilateral is");
Console.WriteLine(" degenerate.");
return(null);
}
}
double area_total = area1 + area2;
//
// Choose a triangle at random, weighted by the areas.
// Then choose a point in that triangle.
//
double[] xy = new double[2 * n];
for (i = 0; i < n; i++)
{
double r = UniformRNG.r8_uniform_01(ref seed);
if (r * area_total < area1)
{
typeMethods.triangle_sample(t1, 1, ref seed, ref xy, +i * 2);
}
else
{
typeMethods.triangle_sample(t2, 1, ref seed, ref xy, +i * 2);
}
}
return(xy);
}
public void RectangularCenter()
{
RunTestCases(testCase => Integrals.Rectangular(testCase.Func, testCase.A, testCase.B, testCase.NodesCount,
Integrals.RectType.Center));
}
public void RectangularRight()
{
RunTestCases(testCase => Integrals.Rectangular(testCase.Func, testCase.A, testCase.B, testCase.NodesCount,
Integrals.RectType.Right));
}
private static void test01()
//****************************************************************************80
//
// Purpose:
//
// TEST01 uses SPHERE01_SAMPLE to estimate monomial integrands.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 06 January 2014
//
// Author:
//
// John Burkardt
//
{
const int m = 3;
int test;
const int test_num = 20;
Console.WriteLine("");
Console.WriteLine("TEST01");
Console.WriteLine(" Estimate monomial integrands using Monte Carlo");
Console.WriteLine(" over the surface of the unit sphere in 3D.");
//
// Get sample points.
//
const int n = 8192;
int seed = 123456789;
double[] x = Integrals.sphere01_sample(n, ref seed);
Console.WriteLine("");
Console.WriteLine(" Number of sample points used is " + n + "");
//
// Randomly choose X,Y,Z exponents between (0,0,0) and (9,9,9).
//
Console.WriteLine("");
Console.WriteLine(" If any exponent is odd, the integral is zero.");
Console.WriteLine(" We will restrict this test to randomly chosen even exponents.");
Console.WriteLine("");
Console.WriteLine(" Ex Ey Ez MC-Estimate Exact Error");
Console.WriteLine("");
for (test = 1; test <= test_num; test++)
{
int[] e = UniformRNG.i4vec_uniform_ab_new(m, 0, 4, ref seed);
int i;
for (i = 0; i < m; i++)
{
e[i] *= 2;
}
double[] value = Monomial.monomial_value(m, n, e, x);
double result = Integrals.sphere01_area() * typeMethods.r8vec_sum(n, value) / n;
double exact = Integrals.sphere01_monomial_integral(e);
double error = Math.Abs(result - exact);
Console.WriteLine(" " + e[0].ToString().PadLeft(2)
+ " " + e[1].ToString().PadLeft(2)
+ " " + e[2].ToString().PadLeft(2)
+ " " + result.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + exact.ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + error.ToString(CultureInfo.InvariantCulture).PadLeft(14) + "");
}
}
public void TestLinear()
{
double value = Integrals.SimpsonAt((x) => 3.0 - x / 2, 1, 4);
Assert.AreEqual(5.25, value, 0.0001);
}
public static double[] triangle_monte_carlo(double[] t, int p_num, int f_num,
Func <int, int, tusData> triangle_unit_sample,
Func <int, double[], int, double[]> triangle_integrand, ref int seed)
//****************************************************************************80
//
// Purpose:
//
// TRIANGLE_MONTE_CARLO applies the Monte Carlo rule to integrate a function.
//
// Discussion:
//
// The function f(x,y) is to be integrated over a triangle T.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 15 August 2009
//
// Author:
//
// John Burkardt
//
// Parameters:
//
// Input, double T[2*3], the triangle vertices.
//
// Input, int P_NUM, the number of sample points.
//
// Input, int F_NUM, the number of functions to integrate.
//
// Input, external TRIANGLE_UNIT_SAMPLE, the sampling routine.
//
// Input, external TRIANGLE_INTEGRAND, the integrand routine.
//
// Input/output, int &SEED, a seed for the random
// number generator.
//
// Output, dobule TRIANGLE_MONTE_CARLO[F_NUM], the approximate integrals.
//
{
int i;
double area = Integrals.triangle_area(t);
tusData data = triangle_unit_sample(p_num, seed);
seed = data.seed;
double[] p = data.result;
double[] p2 = new double[2 * p_num];
Reference.reference_to_physical_t3(t, p_num, p, ref p2);
double[] fp = triangle_integrand(p_num, p2, f_num);
double[] result = new double[f_num];
for (i = 0; i < f_num; i++)
{
double fp_sum = 0.0;
int j;
for (j = 0; j < p_num; j++)
{
fp_sum += fp[i + j * f_num];
}
result[i] = area * fp_sum / p_num;
}
return(result);
}
public void TestConstant()
{
double value = Integrals.SimpsonAt((x) => 1.0, 0, 5);
Assert.AreEqual(5.0, value, 0.0001);
}
public void TrapezoidTest()
{
RunTestCases(
testCase => Integrals.Trapezoid(testCase.Func, GenerateNodes(testCase.A, testCase.B, testCase.NodesCount))
);
}
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 = NewtonCotesOpen.triangle_nco_order_num(rule);
double[] xy = new double[2 * order_num];
double[] xy2 = new double[2 * order_num];
double[] w = new double[order_num];
NewtonCotesOpen.triangle_nco_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).ToString(CultureInfo.InvariantCulture).PadLeft(8)
+ " " + node_xy[0 + node * 2].ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + node_xy[1 + node * 2].ToString(CultureInfo.InvariantCulture).PadLeft(14) + "");
}
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) + "");
}
}