diff options
Diffstat (limited to 'SRC/sstevx.f')
-rw-r--r-- | SRC/sstevx.f | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/SRC/sstevx.f b/SRC/sstevx.f index 215a6c30..42dd8d94 100644 --- a/SRC/sstevx.f +++ b/SRC/sstevx.f @@ -121,24 +121,20 @@ *> An approximate eigenvalue is accepted as converged *> when it is determined to lie in an interval [a,b] *> of width less than or equal to -*> \endverbatim -*> \verbatim +*> *> ABSTOL + EPS * max( |a|,|b| ) , -*> \endverbatim -*> \verbatim +*> *> where EPS is the machine precision. If ABSTOL is less *> than or equal to zero, then EPS*|T| will be used in *> its place, where |T| is the 1-norm of the tridiagonal *> matrix. -*> \endverbatim -*> \verbatim +*> *> Eigenvalues will be computed most accurately when ABSTOL is *> set to twice the underflow threshold 2*SLAMCH('S'), not zero. *> If this routine returns with INFO>0, indicating that some *> eigenvectors did not converge, try setting ABSTOL to *> 2*SLAMCH('S'). -*> \endverbatim -*> \verbatim +*> *> See "Computing Small Singular Values of Bidiagonal Matrices *> with Guaranteed High Relative Accuracy," by Demmel and *> Kahan, LAPACK Working Note #3. |