public static void lpp_value_test()
//****************************************************************************80
//
// Purpose:
//
// LPP_VALUE_TEST tests LPP_VALUE.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 31 October 2014
//
// Author:
//
// John Burkardt
//
{
int i;
const int m = 3;
const int n = 1;
int o = 0;
int rank;
Console.WriteLine("");
Console.WriteLine("LPP_VALUE_TEST:");
Console.WriteLine(" LPP_VALUE evaluates a Legendre product polynomial.");
const double xlo = -1.0;
const double xhi = +1.0;
int seed = 123456789;
double[] x = UniformRNG.r8vec_uniform_ab_new(m, xlo, xhi, ref seed);
Console.WriteLine("");
string cout = " Evaluate at X = ";
for (i = 0; i < m; i++)
{
cout += " " + x[i + 0 * m];
}
Console.WriteLine(cout);
Console.WriteLine("");
Console.WriteLine(" Rank I1 I2 I3: L(I1,X1)*L(I2,X2)*L(I3,X3) P(X1,X2,X3)");
Console.WriteLine("");
for (rank = 1; rank <= 20; rank++)
{
int[] l = Comp.comp_unrank_grlex(m, rank);
//
// Evaluate the LPP directly.
//
double[] v1 = Legendre.lpp_value(m, n, l, x);
//
// Convert the LPP to a polynomial.
//
int o_max = 1;
for (i = 0; i < m; i++)
{
o_max = o_max * (l[i] + 2) / 2;
}
double[] c = new double[o_max];
int[] e = new int[o_max];
Legendre.lpp_to_polynomial(m, l, o_max, ref o, ref c, ref e);
//
// Evaluate the polynomial.
//
double[] v2 = Polynomial.polynomial_value(m, o, c, e, n, x);
//
// Compare results.
//
Console.WriteLine(rank.ToString().PadLeft(6) + " "
+ l[0].ToString().PadLeft(2) + " "
+ l[1].ToString().PadLeft(2) + " "
+ l[2].ToString().PadLeft(2) + " "
+ v1[0].ToString(CultureInfo.InvariantCulture).PadLeft(14) + " "
+ v2[0].ToString(CultureInfo.InvariantCulture).PadLeft(14) + "");
}
}
