// Construct Gauss integration rule.
// nGauss - number of Gauss points in each direction
// (excluding 14-point rule),
// nDim - number of dimensions
public GaussRule(int nGauss, int nDim)
{
if (!((nGauss >= 1 && nGauss <= 3) || nGauss == 14))
{
UTIL.errorMsg("nGauss has forbidden value: " + nGauss);
}
if (!(nDim >= 1 && nDim <= 3))
{
UTIL.errorMsg("GaussRule: nDim has forbidden value: " + nDim);
}
if (nGauss == 14)
{
nIntPoints = 14;
}
else
{
nIntPoints = 1;
for (int i = 0; i < nDim; i++)
{
nIntPoints *= nGauss;
}
}
xii = new double[nIntPoints];
wi = new double[nIntPoints];
if (nDim > 1)
{
eti = new double[nIntPoints];
}
if (nDim > 2)
{
zei = new double[nIntPoints];
}
if (nGauss == 14)
{
for (int i = 0; i < nGauss; i++)
{
xii[i] = X14[i];
eti[i] = Y14[i];
zei[i] = Z14[i];
wi[i] = (i < 8) ? Wa : Wb;
}
}
else
{
int ip = 0;
int n = nGauss - 1;
switch (nDim)
{
case 1:
for (int i = 0; i < nGauss; i++)
{
xii[ip] = X[n][i];
wi[ip++] = W[n][i];
}
break;
case 2:
for (int i = 0; i < nGauss; i++)
{
for (int j = 0; j < nGauss; j++)
{
xii[ip] = X[n][i];
eti[ip] = X[n][j];
wi[ip++] = W[n][i] * W[n][j];
}
}
break;
case 3:
for (int i = 0; i < nGauss; i++)
{
for (int j = 0; j < nGauss; j++)
{
for (int k = 0; k < nGauss; k++)
{
xii[ip] = X[n][i];
eti[ip] = X[n][j];
zei[ip] = X[n][k];
wi[ip++] = W[n][i] * W[n][j] * W[n][k];
}
}
}
break;
}
}
}
