Issues, related to generalized symmetric-definite banded eigenproblem (S|H)BGV/GVD

[dklyuchinskiy]

Hello!

Please take a look into presented checklist.

Checklist

• [x] Redundant space is added after the function name in XERBLA call. Related to (S|H)BGV source files only. I'd be willing to make a PR to solve this issue

     IF( INFO.NE.0 ) THEN
         CALL XERBLA( 'DGBSV ', -INFO )
         RETURN
      END IF

• [ ] Wrong documentation (or memory requirements) for minimal workspace required CHBGVD:

      IF( N.LE.1 ) THEN
         LWMIN = 1+N
         LRWMIN = 1+N
         LIWMIN = 1

but documentations says

          LRWORK is INTEGER
          The dimension of array RWORK.
          If N <= 1,               LRWORK >= 1.

Also in SSBGVD for N case

      ELSE
         liwmin = 1
         lwmin = 2*n
      END IF

but documentations says:

If JOBZ = 'N' and N > 1, LWORK >= 3*N.

• [ ] Problems from previous point are not caught due to missed error check in tests. This branch

1940     ELSE IF( LSAMEN( 3, C3, 'DSG' ) ) THEN

from TESTING/EIG/dchkee.F does not contain error check.

• [ ] Strange commented code in the same branch TESTING/EIG/dchkee.F

Should it be deleted or is there a plan for future implementation?

Best regards, Dmitry