public void constructLinearSystem(BlkSch BS, SparseLinearSystem SPS)
{
BoundaryCondition[] bc = BS.bc;
double[] rhs = SPS.b;
double c2 = BS.c2;
double c1 = BS.c1;
double c0 = BS.c0;
double[] x = BS.x;
double[] sol = BS.sol;
SPS.solution = BS.sol;
double[] source = BS.source;
int n = BS.sol.Length;
applyBoundaryCondition(BS, bc[0], SPS.lower_bc, rhs, x, DIR.LOWER);
applyBoundaryCondition(BS, bc[1], SPS.upper_bc, rhs, x, DIR.UPPER);
for (int i = 1; i < n - 1; ++i)
{
double alpha = 2 * c2 * x[i] * x[i] / ((x[i] - x[i - 1]) * (x[i + 1] - x[i - 1])) - c1 * x[i] / (x[i + 1] - x[i - 1]);
double beta = 2 * c2 * x[i] * x[i] / ((x[i + 1] - x[i]) * (x[i + 1] - x[i - 1])) + c1 * x[i] / (x[i + 1] - x[i - 1]);
SPS.L[i - 1] = -alpha * theta * dt;
SPS.D[i - 1] = 1 + (alpha + beta - c0) * theta * dt;
SPS.R[i - 1] = -beta * theta * dt;
rhs[i] = sol[i - 1] * alpha * (1 - theta) * dt
+ sol[i] * (1 - (alpha + beta - c0) * (1 - theta) * dt)
+ sol[i + 1] * beta * (1 - theta) * dt;
if (source != null)
{
rhs[i] += source[i] * dt;
}
}
}
public void advance(double dt)
{
this.dt = dt;
SparseLinearSystem[] sps = new SparseLinearSystem[bs.Length];
for (int i = 0; i < bs.Length; ++i)
{
sps[i] = new SparseLinearSystem(bs[i].sol.Length);
constructLinearSystem(bs[i], sps[i]);
}
PSOR psor_solver = new PSOR(sps, 1.55, constrain);
psor_solver.tolerance = Math.Min(dt, min_dx) * 0.01;
psor_solver.maxIter = 200;
psor_solver.solve();
Console.WriteLine("Iteration: {0}, Error Norm: {1}", psor_solver.NumIter, psor_solver.ErrorNorm);
}