[Octave-bug-tracker] [bug #55564] GESDD: vastly different singular values when vectors are also requested

[Rik]

Follow-up Comment #4, bug #55564 (project octave):

@Mike: Thanks.  I renamed the function to tst_svd on my platform.  Here is a
sample session which shows changing the backend SVD function to GESVD fixes
the issue.


octave:6> svd_driver ('gesdd')
octave:7> tst_svd (25)
octave:8> tst_svd (26)
error: called from
    assert at line 424 column 7
    tst_svd at line 6 column 3
error: ASSERT errors for:  assert (s1,s2,-10 * eps)

  Location  |  Observed  |  Expected  |  Reason
    (2)      6532088430.599 60796517600.6995   Rel err 0.89256 exceeds tol
2.2204e-15 by 0.9
    (3)           1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (4)           1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (5)           1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (6)           1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (7)           1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (8)           1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (9)           1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (10)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (11)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (12)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (13)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (14)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (15)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (16)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (17)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (18)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (19)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (20)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (21)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (22)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (23)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (24)          1       60796517600.6995   Rel err 1 exceeds tol 2.2204e-15
by 1
    (25)     0.66234006257608 60796517600.6995   Rel err 1 exceeds tol
2.2204e-15 by 1
    (26)     1.5308724083297e-10 2336599984.2757   Rel err 1 exceeds tol
2.2204e-15 by 1
octave:8> svd_driver ('gesvd')
octave:9> tst_svd (25)
octave:10> tst_svd (26)
octave:11> diary off




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