Re: boosting tolerances on gammainc BIST tests

[Rik]

On 02/05/2019 02:13 AM, address@hidden wrote:

Subject:

Re: Tested 5.0.91

From:

Mike Miller <address@hidden>

Date:

02/04/2019 08:32 PM

To:

Christian Himpe <address@hidden>

CC:

Colin Macdonald <address@hidden>, address@hidden

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Hi Christian,

On Tue, Feb 05, 2019 at 01:56:20 +0100, Christian Himpe wrote:

I compiled octave-5.0.91 on Ubuntu 18.04 with the self-compiled
library stack:

* OpenBLAS 0.3.5
* FlexiBLAS 2.0.0
* qrupdate 1.1.2
* SuiteSparse 5.4.0
* arpack-ng 3.7.0
* sundials 2.7.0

When you run the test suite are you using FlexiBLAS with OpenBLAS
selected? I assume so.

Is your Ubuntu system x86-64?

whereas the fails are in:

* plot/appearance/camlookat.m (1 FAIL)
* specfun/gammainc.m (3 FAILs)

In your fntests.log file, all 4 failures are because the difference is
slightly out of the test tolerance.

I think the gammainc.m test tolerances were chosen empirically, and they
have been increased in the past (https://savannah.gnu.org/bugs/?53437).

@Mike: No objection from me to relaxing the tolerances if the miss is only a further few eps.  If it is larger, maybe 10 eps, then it probably deserves a closer look.

Cc'ing Colin to comment on the camlookat.m test results and tolerances:

!!!!! test failed
ASSERT errors for:  assert (dir,dir2,-2 * eps)

  Location  |  Observed  |  Expected  |  Reason
    (2)        0.72803      0.72803      Rel err 4.5749e-16 exceeds tol 4.4409e-16 by 1e-17

@Christian: What OpenGL driver are you using?  Is this software rendering or a dedicated card?

If you switch back to OpenBLAS from FlexiBLAS do the errors go away?

Is the compiler gcc?  version?  Did you use any other configure options like '--disable-float-truncate', or was this a vanilla configure and build?

--Rik