private static void test07()
//****************************************************************************80
//
// Purpose:
//
// TEST07 repeats test 3 using levels.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 30 September 2012
//
// Author:
//
// John Burkardt
//
{
int i;
int j;
Console.WriteLine("");
Console.WriteLine("TEST07:");
Console.WriteLine(" Repeat test #3, using levels.");
Console.WriteLine(" LAGRANGE_INTERP_ND_GRID2 sets the interpolant.");
Console.WriteLine(" LAGRANGE_INTERP_ND_VALUE2 evaluates it.");
int m = 3;
int[] ind = new int[m];
for (i = 0; i < m; i++)
{
ind[i] = 2;
}
double[] a = new double[m];
double[] b = new double[m];
for (i = 0; i < m; i++)
{
a[i] = 0.0;
b[i] = 1.0;
}
int nd = LagrangenD.lagrange_interp_nd_size2(m, ind);
double[] xd = LagrangenD.lagrange_interp_nd_grid2(m, ind, a, b, nd);
double[] zd = f_sinr(m, nd, xd);
//
// Evaluate.
//
Console.WriteLine("");
Console.WriteLine(" Zinterp Zexact Error");
Console.WriteLine("");
int ni = 5;
int seed = 123456789;
double[] xi = UniformRNG.r8mat_uniform_01_new(m, ni, ref seed);
double[] ze = f_sinr(m, ni, xi);
double[] zi = LagrangenD.lagrange_interp_nd_value2(m, ind, a, b, nd, zd, ni, xi);
for (j = 0; j < ni; j++)
{
Console.WriteLine(" " + zi[j].ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + ze[j].ToString(CultureInfo.InvariantCulture).PadLeft(14)
+ " " + Math.Abs(zi[j] - ze[j]).ToString(CultureInfo.InvariantCulture).PadLeft(10) + "");
}
}
private static void test08()
//****************************************************************************80
//
// Purpose:
//
// TEST08 repeats test 4 using levels.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 30 September 2012
//
// Author:
//
// John Burkardt
//
{
int i;
int l;
Console.WriteLine("");
Console.WriteLine("TEST08:");
Console.WriteLine(" Interpolate in 3D, using levels.");
Console.WriteLine(" Use a sequence of increasing levels.");
const int m = 3;
int[] ind = new int[m];
double[] a = new double[m];
double[] b = new double[m];
for (i = 0; i < m; i++)
{
a[i] = 0.0;
b[i] = 1.0;
}
int ni = 20;
int seed = 123456789;
double[] xi = UniformRNG.r8mat_uniform_01_new(m, ni, ref seed);
double[] ze = f_sinr(m, ni, xi);
Console.WriteLine("");
Console.WriteLine(" Level Order Average Error");
Console.WriteLine("");
for (l = 0; l <= 5; l++)
{
for (i = 0; i < m; i++)
{
ind[i] = l;
}
int nd = LagrangenD.lagrange_interp_nd_size2(m, ind);
double[] xd = LagrangenD.lagrange_interp_nd_grid2(m, ind, a, b, nd);
double[] zd = f_sinr(m, nd, xd);
//
// Evaluate.
//
double[] zi = LagrangenD.lagrange_interp_nd_value2(m, ind, a, b, nd, zd, ni, xi);
double e = typeMethods.r8vec_norm_affine(ni, zi, ze) / ni;
Console.WriteLine(" " + l.ToString(CultureInfo.InvariantCulture).PadLeft(5)
+ " " + nd.ToString(CultureInfo.InvariantCulture).PadLeft(5)
+ " " + e.ToString(CultureInfo.InvariantCulture).PadLeft(10) + "");
}
}
private static void test01(int m, int sparse_max)
//****************************************************************************80
//
// Purpose:
//
// TEST01: sequence of sparse interpolants to an M-dimensional function.
//
// Discussion:
//
// We have functions that can generate a Lagrange interpolant to data
// in M dimensions, with specified order or level in each dimension.
//
// We use the Lagrange function as the inner evaluator for a sparse
// grid procedure.
//
// The procedure computes sparse interpolants of levels 0 to SPARSE_MAX
// to a given function.
//
// Licensing:
//
// This code is distributed under the GNU LGPL license.
//
// Modified:
//
// 06 October 2012
//
// Author:
//
// John Burkardt
//
// Parameters:
//
// Local, int M, the spatial dimension.
//
// Input, int SPARSE_MAX, the maximum sparse grid level to try.
//
// Local Parameters:
//
// Local, double A[M], B[M], the upper and lower variable limits
// in each dimension.
//
// Local, double APP_ERROR, the averaged Euclidean norm of the
// difference between the sparse interpolant and the exact function at
// the interpolation points.
//
// Local, int C[L_MAX+1], the sparse grid coefficient vector.
// Results at level L are weighted by C(L).
//
// Local, int IND[M], the 1D indices defining a Lagrange grid.
// Each entry is a 1d "level" that specifies the order of a
// Clenshaw Curtis 1D grid.
//
// Local, int L, the current Lagrange grid level.
//
// Local, int L_MAX, the current sparse grid level.
//
// Local, int MORE, used to control the enumeration of all the
// Lagrange grids at a current grid level.
//
// Local, int ND, the number of points used in a Lagrange grid.
//
// Local, int ND_TOTAL, the total number of points used in all the
// Lagrange interpolants for a given sparse interpolant points that occur
// in more than one Lagrange grid are counted multiple times.
//
// Local, int NI, the number of interpolant evaluation points.
//
// Local, int SPARSE_MIN, the minimum sparse grid level to try.
//
// Local, double XD[M*ND], the data points for a Lagrange grid.
//
// Local, double XI[M*NI], the interpolant evaluation points.
//
// Local, double ZD[ND], the data values for a Lagrange grid.
//
// Local, double ZE[NI], the exact function values at XI.
//
// Local, double ZI[NI], the sparse interpolant values at XI.
//
// Local, double ZPI[NI], one set of Lagrange interpolant values at XI.
//
{
int h = 0;
int i;
int l_max;
int t = 0;
Console.WriteLine("");
Console.WriteLine("TEST01:");
Console.WriteLine(" Sparse interpolation for a function f(x) of M-dimensional argument.");
Console.WriteLine(" Use a sequence of sparse grids of levels 0 through SPARSE_MAX.");
Console.WriteLine(" Invoke a general Lagrange interpolant function to do this.");
Console.WriteLine("");
Console.WriteLine(" Compare the exact function and the interpolants at a grid of points.");
Console.WriteLine("");
Console.WriteLine(" The \"order\" is the sum of the orders of all the product grids");
Console.WriteLine(" used to make a particular sparse grid.");
//
// User input.
//
Console.WriteLine("");
Console.WriteLine(" Spatial dimension M = " + m + "");
Console.WriteLine(" Maximum sparse grid level = " + sparse_max + "");
//
// Define the region.
//
double[] a = new double[m];
double[] b = new double[m];
for (i = 0; i < m; i++)
{
a[i] = 0.0;
b[i] = 1.0;
}
//
// Define the interpolation evaluation information.
//
const int ni = 100;
int seed = 123456789;
double[] xi = UniformRNG.r8mat_uniform_abvec_new(m, ni, a, b, ref seed);
Console.WriteLine(" Number of interpolation points is NI = " + ni + "");
double[] ze = f_sinr(m, ni, xi);
//
// Compute a sequence of sparse grid interpolants of increasing level.
//
Console.WriteLine("");
Console.WriteLine(" L Order ApproxError");
Console.WriteLine("");
int[] ind = new int[m];
double[] zi = new double[ni];
const int sparse_min = 0;
for (l_max = sparse_min; l_max <= sparse_max; l_max++)
{
int[] c = new int[l_max + 1];
int[] w = new int[l_max + 1];
Smolyak.smolyak_coefficients(l_max, m, ref c, ref w);
for (i = 0; i < ni; i++)
{
zi[i] = 0.0;
}
int nd_total = 0;
int l_min = Math.Max(l_max + 1 - m, 0);
int l;
for (l = l_min; l <= l_max; l++)
{
bool more = false;
while (true)
{
//
// Define the next product grid.
//
Comp.comp_next(l, m, ref ind, ref more, ref h, ref t);
//
// Count the grid, find its points, evaluate the data there.
//
int nd = LagrangenD.lagrange_interp_nd_size2(m, ind);
double[] xd = LagrangenD.lagrange_interp_nd_grid2(m, ind, a, b, nd);
double[] zd = f_sinr(m, nd, xd);
//
// Use the grid to evaluate the interpolant.
//
double[] zpi = LagrangenD.lagrange_interp_nd_value2(m, ind, a, b, nd, zd, ni, xi);
//
// Weighted the interpolant values and add to the sparse grid interpolant.
//
nd_total += nd;
for (i = 0; i < ni; i++)
{
zi[i] += c[l] * zpi[i];
}
if (!more)
{
break;
}
}
}
//
// Compare sparse interpolant and exact function at interpolation points.
//
double app_error = typeMethods.r8vec_norm_affine(ni, zi, ze) / ni;
Console.WriteLine(" " + l.ToString(CultureInfo.InvariantCulture).PadLeft(2)
+ " " + nd_total.ToString(CultureInfo.InvariantCulture).PadLeft(8)
+ " " + app_error.ToString(CultureInfo.InvariantCulture).PadLeft(8) + "");
}
}