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| author | langou <langou@users.noreply.github.com> | 2015-05-05 01:00:18 +0000 |
|---|---|---|
| committer | langou <langou@users.noreply.github.com> | 2015-05-05 01:00:18 +0000 |
| commit | c20d8cceca87568fb1aa1f26a0248b269e8c99d2 (patch) | |
| tree | 4fad85778f803ef52402b3e33f146d810ebd8957 /SRC/dstein.f | |
| parent | c2bb35e025810d6e7c23c74f2858227f338c97df (diff) | |
Bug fix from Osni Marques, Beresford Parlett and Jim Demmel.
This fixes bugs 032 and 056.
Edits in cstein.f, dstein.f, sstein.f and zstein.f
From Osni on Monday, May 4:
As we discussed in our last conference call, I am attaching a new version of
_STEIN, which fixes bugs 032 and 056. (The bugs were reported for DSTEIN, but
I have propagated the fix to the other versions.) Also, in the process of
testing the fix for those two bugs with more difficult cases, we stumbled upon
a matrix that led SSTEIN to return NaNs in the eigenvectors ... We fixed that
too and, in summary, these are the changes in _STEIN:
1) The assignment after the GO TO 60 needs to be GPIND = J1 (instead of GPIND =
B1).
2) In 'Normalize and scale the righthand side vector Pb' (after GO TO 100 or GO
TO 120) we have replaced _ASUM with I_AMAX.
Diffstat (limited to 'SRC/dstein.f')
| -rw-r--r-- | SRC/dstein.f | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/SRC/dstein.f b/SRC/dstein.f index 7cc372b2..ddc84fe2 100644 --- a/SRC/dstein.f +++ b/SRC/dstein.f @@ -297,7 +297,7 @@ BLKSIZ = BN - B1 + 1 IF( BLKSIZ.EQ.1 ) $ GO TO 60 - GPIND = B1 + GPIND = J1 * * Compute reorthogonalization criterion and stopping criterion. * @@ -370,9 +370,10 @@ * * Normalize and scale the righthand side vector Pb. * + JMAX = IDAMAX( BLKSIZ, WORK( INDRV1+1 ), 1 ) SCL = BLKSIZ*ONENRM*MAX( EPS, $ ABS( WORK( INDRV4+BLKSIZ ) ) ) / - $ DASUM( BLKSIZ, WORK( INDRV1+1 ), 1 ) + $ ABS( WORK( INDRV1+JMAX ) ) CALL DSCAL( BLKSIZ, SCL, WORK( INDRV1+1 ), 1 ) * * Solve the system LU = Pb. |