/**
* @param A coefficient matrix
* @param A_QR Householder QR decomposition of coefficient matrix
* @param b right-hand side
* @param[out] x solution of the linear system
* @return whether all went well (false if errors occurred)
*/
bool solveInternal(const EigenMatrix& A, const ::Eigen::HouseholderQR<EigenMatrix>& A_QR,
base::DataVector& b, base::DataVector& x) {
const SGPP::float_t tolerance =
#if USE_DOUBLE_PRECISION
1e-12;
#else
1e-4;
#endif
// solve system
EigenVector bEigen = EigenVector::Map(b.getPointer(), b.getSize());
EigenVector xEigen = A_QR.solve(bEigen);
// check solution
if ((A * xEigen).isApprox(bEigen, tolerance)) {
x = base::DataVector(xEigen.data(), xEigen.size());
return true;
} else {
return false;
}
}
void ctms_decompositions()
{
const int maxSize = 16;
const int size = 12;
typedef Eigen::Matrix<Scalar,
Eigen::Dynamic, Eigen::Dynamic,
0,
maxSize, maxSize> Matrix;
typedef Eigen::Matrix<Scalar,
Eigen::Dynamic, 1,
0,
maxSize, 1> Vector;
typedef Eigen::Matrix<std::complex<Scalar>,
Eigen::Dynamic, Eigen::Dynamic,
0,
maxSize, maxSize> ComplexMatrix;
const Matrix A(Matrix::Random(size, size)), B(Matrix::Random(size, size));
Matrix X(size,size);
const ComplexMatrix complexA(ComplexMatrix::Random(size, size));
const Matrix saA = A.adjoint() * A;
const Vector b(Vector::Random(size));
Vector x(size);
// Cholesky module
Eigen::LLT<Matrix> LLT; LLT.compute(A);
X = LLT.solve(B);
x = LLT.solve(b);
Eigen::LDLT<Matrix> LDLT; LDLT.compute(A);
X = LDLT.solve(B);
x = LDLT.solve(b);
// Eigenvalues module
Eigen::HessenbergDecomposition<ComplexMatrix> hessDecomp; hessDecomp.compute(complexA);
Eigen::ComplexSchur<ComplexMatrix> cSchur(size); cSchur.compute(complexA);
Eigen::ComplexEigenSolver<ComplexMatrix> cEigSolver; cEigSolver.compute(complexA);
Eigen::EigenSolver<Matrix> eigSolver; eigSolver.compute(A);
Eigen::SelfAdjointEigenSolver<Matrix> saEigSolver(size); saEigSolver.compute(saA);
Eigen::Tridiagonalization<Matrix> tridiag; tridiag.compute(saA);
// LU module
Eigen::PartialPivLU<Matrix> ppLU; ppLU.compute(A);
X = ppLU.solve(B);
x = ppLU.solve(b);
Eigen::FullPivLU<Matrix> fpLU; fpLU.compute(A);
X = fpLU.solve(B);
x = fpLU.solve(b);
// QR module
Eigen::HouseholderQR<Matrix> hQR; hQR.compute(A);
X = hQR.solve(B);
x = hQR.solve(b);
Eigen::ColPivHouseholderQR<Matrix> cpQR; cpQR.compute(A);
X = cpQR.solve(B);
x = cpQR.solve(b);
Eigen::FullPivHouseholderQR<Matrix> fpQR; fpQR.compute(A);
// FIXME X = fpQR.solve(B);
x = fpQR.solve(b);
// SVD module
Eigen::JacobiSVD<Matrix> jSVD; jSVD.compute(A, ComputeFullU | ComputeFullV);
}