/// Solve multiple systems w/ each column of the Matrix a single RHS
MatrixType *p_solve(const MatrixType& B) const
{
VectorType b(B.communicator(), B.localRows());
VectorType X(B.communicator(), B.localRows());
MatrixType *result(new MatrixType(B.communicator(), B.localRows(), B.localCols(), Dense));
int ilo, ihi;
X.localIndexRange(ilo, ihi);
int nloc(X.localSize());
std::vector<IdxType> iidx;
iidx.reserve(nloc);
for (IdxType i = ilo; i < ihi; ++i) { iidx.push_back(i); }
std::vector<IdxType> jidx(nloc);
std::vector<TheType> locX(nloc);
for (int j = 0; j < B.cols(); ++j) {
column(B, j, b);
X.zero();
X.ready();
if (j == 0) {
this->solve(b, X);
} else {
this->resolve(b, X);
}
std::fill(jidx.begin(), jidx.end(), j);
X.getElements(nloc, &iidx[0], &locX[0]);
result->setElements(nloc, &iidx[0], &jidx[0], &locX[0]);
}
result->ready();
return result;
}
void DenseSubmatrix(Sparse<Scalar>& matrix, std::vector<int>& rows,
std::vector<int>& cols, Dense<Scalar>& submatrix) {
#ifndef RELEASE
CallStackEntry entry("DenseSubmatrix");
#endif
// TODO: avoid this copy
Vector<int> iidx(rows.size());
for (size_t i = 0; i < rows.size(); ++i) {
iidx.Set(i, rows[i]);
}
Vector<int> jidx(cols.size());
for (size_t j = 0; j < cols.size(); ++j) {
jidx.Set(j, cols[j]);
}
submatrix.Resize(iidx.Size(), jidx.Size());
matrix.Find(iidx, jidx, submatrix);
}
