diff options
| -rw-r--r-- | SRC/dlarrv.f | 10 | ||||
| -rw-r--r-- | SRC/slarrv.f | 10 |
2 files changed, 16 insertions, 4 deletions
diff --git a/SRC/dlarrv.f b/SRC/dlarrv.f index 8006a75c..4e8d204b 100644 --- a/SRC/dlarrv.f +++ b/SRC/dlarrv.f @@ -68,8 +68,14 @@ *> \verbatim *> VU is DOUBLE PRECISION *> Upper bound of the interval that contains the desired -*> eigenvalues. VL < VU. Needed to compute gaps on the left or right -*> end of the extremal eigenvalues in the desired RANGE. +*> eigenvalues. VL < VU. +*> Note: VU is currently not used by this implmentation of DLARRV, VU is +*> passed to DLARRV because it could be used compute gaps on the right end +*> of the extremal eigenvalues. However, with not much initial accuracy in +*> LAMBDA and VU, the formula can lead to an overestimation of the right gap +*> and thus to inadequately early RQI 'convergence'. This is currently +*> prevented this by forcing a small right gap. And so it turns out that VU +*> is currently not used by this implementation of DLARRV. *> \endverbatim *> *> \param[in,out] D diff --git a/SRC/slarrv.f b/SRC/slarrv.f index 73bebb34..675aac3d 100644 --- a/SRC/slarrv.f +++ b/SRC/slarrv.f @@ -68,8 +68,14 @@ *> \verbatim *> VU is REAL *> Upper bound of the interval that contains the desired -*> eigenvalues. VL < VU. Needed to compute gaps on the left or right -*> end of the extremal eigenvalues in the desired RANGE. +*> eigenvalues. VL < VU. +*> Note: VU is currently not used by this implmentation of SLARRV, VU is +*> passed to SLARRV because it could be used compute gaps on the right end +*> of the extremal eigenvalues. However, with not much initial accuracy in +*> LAMBDA and VU, the formula can lead to an overestimation of the right gap +*> and thus to inadequately early RQI 'convergence'. This is currently +*> prevented this by forcing a small right gap. And so it turns out that VU +*> is currently not used by this implementation of SLARRV. *> \endverbatim *> *> \param[in,out] D |