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-rw-r--r--Eigen/src/SVD/JacobiSVD.h11
1 files changed, 9 insertions, 2 deletions
diff --git a/Eigen/src/SVD/JacobiSVD.h b/Eigen/src/SVD/JacobiSVD.h
index bf1213656..eee31ca97 100644
--- a/Eigen/src/SVD/JacobiSVD.h
+++ b/Eigen/src/SVD/JacobiSVD.h
@@ -411,8 +411,8 @@ struct svd_precondition_2x2_block_to_be_real<MatrixType, QRPreconditioner, true>
template<typename MatrixType, typename RealScalar, typename Index>
void real_2x2_jacobi_svd(const MatrixType& matrix, Index p, Index q,
- JacobiRotation<RealScalar> *j_left,
- JacobiRotation<RealScalar> *j_right)
+ JacobiRotation<RealScalar> *j_left,
+ JacobiRotation<RealScalar> *j_right)
{
using std::sqrt;
Matrix<RealScalar,2,2> m;
@@ -831,6 +831,11 @@ JacobiSVD<MatrixType, QRPreconditioner>::compute(const MatrixType& matrix, unsig
if(m_computeFullV) m_matrixV.setIdentity(m_cols,m_cols);
if(m_computeThinV) m_matrixV.setIdentity(m_cols, m_diagSize);
}
+
+ // Scaling factor to reducover/under-flows
+ RealScalar scale = m_workMatrix.cwiseAbs().maxCoeff();
+ if(scale==RealScalar(0)) scale = RealScalar(1);
+ m_workMatrix /= scale;
/*** step 2. The main Jacobi SVD iteration. ***/
@@ -879,6 +884,8 @@ JacobiSVD<MatrixType, QRPreconditioner>::compute(const MatrixType& matrix, unsig
m_singularValues.coeffRef(i) = a;
if(computeU() && (a!=RealScalar(0))) m_matrixU.col(i) *= m_workMatrix.coeff(i,i)/a;
}
+
+ m_singularValues *= scale;
/*** step 4. Sort singular values in descending order and compute the number of nonzero singular values ***/