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[Lapack] Fw: Question about dspevx error handling.



Another thing I noticed is that if DSTEIN returns with INFO>0,  the INFO
will be reset to ZERO by the call to dopmtr that follows.  Therefore, we
would never get the INFO>0 situation described in the prolog of DSPEVX.

Regards,
Phil DeMier
(demier@Domain.Removed)


----- Forwarded by Phil DeMier/Poughkeepsie/IBM on 03/19/2008 11:14 AM
-----
                                                                           
             Phil                                                          
             DeMier/Poughkeeps                                             
             ie/IBM                                                     To 
                                       lapack@Domain.Removed                   
             03/19/2008 10:47                                           cc 
             AM                                                            
                                                                   Subject 
                                       Question about dspevx error         
                                       handling.                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           



Greetings,
  The INFO parameter for dspevx only describes a failure with eigenvectors
failing to converge.

      INFO    (output) INTEGER
              = 0:  successful exit
              < 0:  if INFO = -i, the i-th argument had an illegal value
              > 0:  if INFO = i, then i eigenvectors failed to converge.
                    Their indices are stored in array IFAIL.

If DSTEBZ fails and JOBZ='N', then dspevx will return with INFO>0 but it
has nothing to do with an eigenvector converging failure.
Should INFO be set to zero after DSTEBZ returns?

Thanks and best regards,
Phil DeMier.
(demier@Domain.Removed)
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