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[Lapack] Error in LAPACK auxiliary routine dlagv2


I would like to inform you about an error in the LAPACK auxiliary routine
dlagv2 (version dated 20 august 2009).

Specifically, the variable WI, which is used in the line 268 (close to the
end), is not initialized (with ZERO) in the cases "A can be deflated"
and "B is singular" (i.e., the code segments in the lines 138-144, 148-156,
and 158-167).

The corrected version is included in the attached archive.  Included is
also a further modified version (dlagv2_m), which makes slightly less
operations in the DROT calls.  It uses the value of the nonzero component
of the rotated vector, already computed by the preceding DLARTG call, and
does not compute the values which are then set to zero.  I made no tests
yet with dlagv2_m version.

Sincerely yours,
Vasile Sima

Dr. Vasile Sima,  SMIEEE
National Institute for Research & Development in Informatics
Bd. Maresal Al. Averescu, Nr. 8-10
011455, Bucharest 1,  Romania
Phone:   (+40)-21-316.07.65  (in Romania: 021-316.07.65)
Fax:     (+40)-21-316.10.30  (in Romania: 021-316.10.30)
E-mail:  vsima@Domain.Removed
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