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add an optimized "apply in place a rotation in the plane",

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and make Jacobi and SelfAdjointEigenSolver use it
=> ~ x1.75 speedup for JacobiSVD and x2 for SelfAdjointEigenSolver
This commit is contained in:
Gael Guennebaud
2009-08-13 11:42:02 +02:00
parent 1d80f561ad
commit 1b257a7620
4 changed files with 136 additions and 27 deletions
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18
Eigen/src/Jacobi/Jacobi.h
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@@ -28,23 +28,17 @@
template<typename Derived>
void MatrixBase<Derived>::applyJacobiOnTheLeft(int p, int q, Scalar c, Scalar s)
{
for(int i = 0; i < cols(); ++i)
{
Scalar tmp = coeff(p,i);
coeffRef(p,i) = c * tmp - s * coeff(q,i);
coeffRef(q,i) = s * tmp + c * coeff(q,i);
}
RowXpr x(row(p));
RowXpr y(row(q));
ei_apply_rotation_in_the_plane(x, y, c, s);
}
template<typename Derived>
void MatrixBase<Derived>::applyJacobiOnTheRight(int p, int q, Scalar c, Scalar s)
{
for(int i = 0; i < rows(); ++i)
{
Scalar tmp = coeff(i,p);
coeffRef(i,p) = c * tmp - s * coeff(i,q);
coeffRef(i,q) = s * tmp + c * coeff(i,q);
}
ColXpr x(col(p));
ColXpr y(col(q));
ei_apply_rotation_in_the_plane(x, y, c, s);
}
template<typename Scalar>