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Fix regression in a previous commit: some diagonal entry might not be treated by the 2x2 real preconditioner.

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This commit is contained in:
Gael Guennebaud 2016-07-13 18:37:54 +02:00
parent 20f7ef2f89
commit 5ea0864c81
1 changed files with 16 additions and 14 deletions
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30
Eigen/src/SVD/JacobiSVD.h
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@ -694,16 +694,6 @@ JacobiSVD<MatrixType, QRPreconditioner>::compute(const MatrixType& matrix, unsig
/*** step 2. The main Jacobi SVD iteration. ***/
RealScalar maxDiagEntry = m_workMatrix.cwiseAbs().diagonal().maxCoeff();
// For a 1x1 complex matrix this boils down in cancelling the imaginary part
// This needs to be done explicitly because the "svd_precondition_2x2_block_to_be_real"
// wont't be applied as there is no 2x2 blocks!
if(NumTraits<Scalar>::IsComplex && m_diagSize==1 && abs(numext::imag(m_workMatrix.coeff(0,0)))>considerAsZero)
{
RealScalar z = abs(m_workMatrix.coeff(0,0));
if(computeU()) m_matrixU.col(0) *= m_workMatrix.coeff(0,0)/z;
m_workMatrix.coeffRef(0,0) = z;
}
bool finished = false;
while(!finished)
{
@ -748,10 +738,22 @@ JacobiSVD<MatrixType, QRPreconditioner>::compute(const MatrixType& matrix, unsig
for(Index i = 0; i < m_diagSize; ++i)
{
// At this stage, m_workMatrix.coeff(i,i) is supposed to be real.
RealScalar a = numext::real(m_workMatrix.coeff(i,i));
m_singularValues.coeffRef(i) = abs(a);
if(computeU() && (a<RealScalar(0))) m_matrixU.col(i) = -m_matrixU.col(i);
// For a complex matrix, some diagonal coefficients might note have been
// treated by svd_precondition_2x2_block_to_be_real, and the imaginary part
// of some diagonal entry might not be null.
if(NumTraits<Scalar>::IsComplex && abs(numext::imag(m_workMatrix.coeff(i,i)))>considerAsZero)
{
RealScalar a = abs(m_workMatrix.coeff(i,i));
m_singularValues.coeffRef(i) = abs(a);
if(computeU()) m_matrixU.col(i) *= m_workMatrix.coeff(i,i)/a;
}
else
{
// m_workMatrix.coeff(i,i) is already real, no difficulty:
RealScalar a = numext::real(m_workMatrix.coeff(i,i));
m_singularValues.coeffRef(i) = abs(a);
if(computeU() && (a<RealScalar(0))) m_matrixU.col(i) = -m_matrixU.col(i);
}
}
m_singularValues *= scale;