Add rcond method to LDLT.

This commit is contained in:
Rasmus Munk Larsen
2016-04-01 16:48:38 -07:00
parent f54137606e
commit 9d51f7c457
2 changed files with 59 additions and 12 deletions

View File

@@ -160,6 +160,15 @@ template<typename MatrixType> void cholesky(const MatrixType& m)
matX = ldltlo.solve(matB);
VERIFY_IS_APPROX(symm * matX, matB);
// Verify that the estimated condition number is within a factor of 10 of the
// truth.
const MatrixType symmLo_inverse = ldltlo.solve(MatrixType::Identity(rows,cols));
RealScalar rcond = (RealScalar(1) / matrix_l1_norm<MatrixType, Lower>(symmLo)) /
matrix_l1_norm<MatrixType, Lower>(symmLo_inverse);
RealScalar rcond_est = ldltlo.rcond();
VERIFY(rcond_est > rcond / 10 && rcond_est < rcond * 10);
LDLT<SquareMatrixType,Upper> ldltup(symmUp);
VERIFY_IS_APPROX(symm, ldltup.reconstructedMatrix());
vecX = ldltup.solve(vecB);
@@ -167,6 +176,14 @@ template<typename MatrixType> void cholesky(const MatrixType& m)
matX = ldltup.solve(matB);
VERIFY_IS_APPROX(symm * matX, matB);
// Verify that the estimated condition number is within a factor of 10 of the
// truth.
const MatrixType symmUp_inverse = ldltup.solve(MatrixType::Identity(rows,cols));
rcond = (RealScalar(1) / matrix_l1_norm<MatrixType, Upper>(symmUp)) /
matrix_l1_norm<MatrixType, Upper>(symmUp_inverse);
rcond_est = ldltup.rcond();
VERIFY(rcond_est > rcond / 10 && rcond_est < rcond * 10);
VERIFY_IS_APPROX(MatrixType(ldltlo.matrixL().transpose().conjugate()), MatrixType(ldltlo.matrixU()));
VERIFY_IS_APPROX(MatrixType(ldltlo.matrixU().transpose().conjugate()), MatrixType(ldltlo.matrixL()));
VERIFY_IS_APPROX(MatrixType(ldltup.matrixL().transpose().conjugate()), MatrixType(ldltup.matrixU()));