diff options
| author |  Gael Guennebaud <g.gael@free.fr> | 2014-12-08 16:44:05 +0100 |
|---|---|---|
| committer | Gael Guennebaud <g.gael@free.fr> | 2014-12-08 16:44:05 +0100 |
| commit | 5fc4ce64492a0c791691204dbb465570d7b4a70d (patch) | |
| tree | 4637b40d96637b652a45e145c2b56919cae2142b /unsupported/Eigen/src/MatrixFunctions | |
| parent | 77294047d68ea07c90ddabddbc4cee5dd97c5237 (diff) | |
bug #876: remove usage of atanh2 in matrix power
Diffstat (limited to 'unsupported/Eigen/src/MatrixFunctions')
| -rw-r--r-- | unsupported/Eigen/src/MatrixFunctions/MatrixPower.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/unsupported/Eigen/src/MatrixFunctions/MatrixPower.h b/unsupported/Eigen/src/MatrixFunctions/MatrixPower.h index ee665c18e..1e5a59c55 100644 --- a/unsupported/Eigen/src/MatrixFunctions/MatrixPower.h +++ b/unsupported/Eigen/src/MatrixFunctions/MatrixPower.h @@ -299,7 +299,7 @@ MatrixPowerAtomic<MatrixType>::computeSuperDiag(const ComplexScalar& curr, const ComplexScalar logCurr = log(curr); ComplexScalar logPrev = log(prev); int unwindingNumber = ceil((numext::imag(logCurr - logPrev) - M_PI) / (2*M_PI)); - ComplexScalar w = numext::atanh2(curr - prev, curr + prev) + ComplexScalar(0, M_PI*unwindingNumber); + ComplexScalar w = numext::log1p((curr-prev)/prev)/RealScalar(2) + ComplexScalar(0, M_PI*unwindingNumber); return RealScalar(2) * exp(RealScalar(0.5) * p * (logCurr + logPrev)) * sinh(p * w) / (curr - prev); } @@ -311,7 +311,7 @@ MatrixPowerAtomic<MatrixType>::computeSuperDiag(RealScalar curr, RealScalar prev using std::log; using std::sinh; - RealScalar w = numext::atanh2(curr - prev, curr + prev); + RealScalar w = numext::log1p((curr-prev)/prev)/RealScalar(2); return 2 * exp(p * (log(curr) + log(prev)) / 2) * sinh(p * w) / (curr - prev); } |