GitHub-Proxy/eigen
1
0
Fork 0
mirror of https://gitlab.com/libeigen/eigen.git synced 2025-08-12 11:49:02 +08:00
Code Issues Packages Projects Releases Wiki Activity

bug #876: remove usage of atanh2 in matrix power

Browse Source
This commit is contained in:
Gael Guennebaud 2014-12-08 16:44:05 +01:00
parent 77294047d6
commit 5fc4ce6449
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
unsupported/Eigen/src/MatrixFunctions/MatrixPower.h
View File

@ -299,7 +299,7 @@ MatrixPowerAtomic<MatrixType>::computeSuperDiag(const ComplexScalar& curr, const
ComplexScalar logCurr = log(curr); ComplexScalar logCurr = log(curr);
ComplexScalar logPrev = log(prev); ComplexScalar logPrev = log(prev);
int unwindingNumber = ceil((numext::imag(logCurr - logPrev) - M_PI) / (2*M_PI)); 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); 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::log;
using std::sinh; 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); return 2 * exp(p * (log(curr) + log(prev)) / 2) * sinh(p * w) / (curr - prev);
} }