int main(int argc, char** argv) { cout << "> Creating sm <" << endl; SparseMatrix<int> sm; cin >> sm; cout << sm << endl; sm.Output(cout); SparseMatrix<int> tsm; sm.Transpose(tsm); cout << tsm << endl; tsm.Output(cout); //------------------------------------------------------- cout << "> Creating sm2 <" << endl; SparseMatrix<int> sm2; cin >> sm2; cout << sm2 << endl; sm2.Output(cout); SparseMatrix<int> sm3; sm.Add(sm2, sm3); cout << sm3 << endl; sm3.Output(cout); return 0; }
void StableFluid3D::initPoisson() { clearPoisson(); int n = resX * resY * resZ; for (int i = 0; i < 2; ++i) { r.push_back(Vector(n)); z.push_back(Vector(n)); } p.Resize(n); SparseMatrix hTranspose; SparseMatrix h; laplacian = SparseMatrix(n, n); hTranspose = SparseMatrix(n, n); h = SparseMatrix(n, n); preconditioner = SparseMatrix(n, n); pressure.Resize(n); tempPressure.Resize(n); vel.Resize(n); ones.Resize(n); for (int i = 0; i < n; ++i) { ones[i] = 1; } double rdxSqr = (resX * resX) / (width * width); double rdySqr = (resY * resY) / (height * height); double rdzSqr = (resZ * resZ) / (depth * depth); // initialize values for the laplacian matrix for (int i = 0; i < resX; ++i) { for (int j = 0; j < resY; ++j) { for (int k = 0; k < resZ; ++k) { int row = makeIndex(i, j, k); int x1 = (i == (resX - 1) ? row : row + 1); int x2 = (i == 0 ? row : row - 1); int y1 = (j == (resY - 1) ? row : row + resX); int y2 = (j == 0 ? row : row - resX); int z1 = (k == (resZ - 1) ? row : row + resY * resX); int z2 = (k == 0 ? row : row - resY * resX); laplacian[row][row] += 6 * (rdxSqr + rdySqr + rdzSqr); laplacian[row][x1] -= rdxSqr; laplacian[row][x2] -= rdxSqr; laplacian[row][y1] -= rdySqr; laplacian[row][y2] -= rdySqr; laplacian[row][z1] -= rdzSqr; laplacian[row][z2] -= rdzSqr; } } } // perform Cholesky preconditioning // decompose laplacian into H * H^T SparseVector::iterator iter; hTranspose = laplacian.Transpose(); SparseMatrix& A = hTranspose; for (int k = 0; k < n; ++k) { SparseVector::iterator aik(A[k]); aik.seek(k); if (aik.getIndex() != k) { assert(0); } double divisor = std::sqrt(*aik); *aik = divisor; aik++; while (aik) { *aik /= divisor; aik++; } SparseVector::iterator ajk(A[k]); ajk.seek(k + 1); while (ajk) { int j = ajk.getIndex(); aik.reset(); aik.seek(j); SparseVector::iterator aij(A[j]); aij.seek(j); while (aij && aik) { int i = aij.getIndex(); if (aik.getIndex() == i) { *aij -= (*aik) * (*ajk); aik++; } aij++; if (aij) { i = aij.getIndex(); while (aik && aik.getIndex() < i) { aik++; } } } ajk++; } } h = hTranspose.Transpose(); // cerr<<"Sparsity of laplacian is " << laplacian.Sparsity() << endl; preconditioner = h.FastMultiplyTranspose(); int maxIndex = resX * resY * resZ; // for (int i = 0; i < maxIndex; ++i) // preconditioner[i][i] = 1; // cerr<<"Sparsity of preconditioner is " << preconditioner.Sparsity() << endl; }