Re: svds test failures

[Tatsuro MATSUOKA]

Hello

The results perhaps depend on the kind of blas.
Today I built OpenBLAS-a546694 and replace from altas-3.9.19 with 
OpenBLAS-a546694.

For 
%! randn ('state',42);      % Initialize to make normest function reproducible
%! rand ('state', 42)

give
warning: returning fewer singular values than requested
warning: try increasing the value of sigma
  ***** testif HAVE_UMFPACK
 [u2,s2,v2,flag] = svds(A,k,0,opts);
 s2 = diag(s2);
 assert(flag,!1);
 assert(s2, s(k:-1:1), 1e-10);
!!!!! test failed
assert (s2,s (k:-1:1),1e-10) expected
   38.060
   38.034
   38.034
   38.015
   38.015
   38.004
   38.004
but got
   38.034
   38.034
   38.015
   38.015
   38.004
   38.004
Dimensions don't match

The seed 42 gave no error for atlas-3.9.19.

****The results are 
    ATLAS OpenBLAS
35 OKOK
36 OK       OK
37 fail       OK
38 OK 
39 OK 
40 OK 
41 OK 
42 OK 
43 fail 
44 OK 
45 OK 
46 OK 
47 OK 
48 OK 
49 fail 
50 OK 
--- On Tue, 2011/8/9, Marco atzeri  wrote:

> On 8/9/2011 6:28 AM, Rik wrote:
> > On 08/08/2011 08:11 PM, Liam Groener wrote:
> >> On Aug 8, 2011, at 10:01 AM, Rik wrote:
> >>
> >>> 8/8/11
> >>>
> >>> Marco, Tatsuro,
> >>>
> >>> I've combined the list of initialization values which are acceptable for
> >>> Cygwin, MinGW, and Linux and it amounts to just [35, 40].
> >>>
> >>> Could someone with a MacOS system try those two values in svds.m?  Below
> >>> are the two lines to change.
> >>>
> >>> ------
> >>> %! randn ('state', 35);      % Initialize to make normest function 
> >>> reproducible
> >>> %! rand ('state', 35)
> >>> ------
> >>>
> >>> After each change run the following code
> >>>
> >>> for i = 1:300
> >>>   bm(i) = test ("svds");
> >>> endfor
> >>> sum (bm)
> >>>
> >>> If the sum is not 300 then neither of the values will work.
> >>>
> >>> --Rik
> >> I haven't seen any replies yet, so I tested on OS X 10.7, Octave 3.4.2. 
> >> Neither 35 nor 40 worked, 42 did.
> >
> > Well this is great.  Apparently there is no single value that works for all
> > platforms.  The value 42 did work for Linux, Mac, and MinGW, but not for
> > Cygwin.  I am going to revert to 42 since that works with the most
> > platforms and then it will need to be debugged why svds is failing on 
> > Cygwin.
> >
> > Thanks Liam for the test on Mac platforms.
> >
> > --Rik
> 
> Hi Rik,
> 
> 42 is fine. I will ignore the failure and put a note for myself.
> 
> As all the platform react differently changing the seed , we can assume 
> one of:
> 
> 1) cygwin doesn't like
>      http://en.wikipedia.org/wiki/The_Hitchhiker%27s_Guide_to_the_Galaxy
> 
> 2) Are rand/randn  producing different outcome on different platform ?
> 
> 3) This test is on the borderline and different rounding/libraries will 
> produce different outcome. Should we find a less critical matrix ?
> 
> I remember the test in the past was passing sometime with lapack and 
> always with atlas. But it was before the arpack merge in octave and with 
> previous gcc compiler. Eventually moving to gcc-4.5 the thing will 
> change again on cygwin
> 
> Regards
> Marco
>