Re: [Help-gsl] eigen test fails on 32-bit (x86) Linux

[Martin Jansche]

I'm not sure if GSL makes any guarantees about the direction of
eigenvectors. It looks like the test might pass if one only looks at the
magnitude of the values. Perhaps the test could be made robust against sign
changes by looking at absolute values.



On Mon, Aug 18, 2014 at 1:53 PM, address@hidden <
address@hidden> wrote:

> Hello,
>
> I noticed that eigen test fails on 32-bit Linux (x86) when compiled with
> -O3 flag:
>
> $ ./configure CFLAGS="-O3"
> $ make
> $ eigen/test
> FAIL: gen, direct eigenvalue(4) imag, random (-0.481216772353650846
> observed vs 0.481216772353650846 expected) [877968]
> FAIL: gen, direct eigenvalue(5) imag, random (0.481216772353650901 observed
> vs -0.481216772353650846 expected) [877970]
> FAIL: gen, direct eigenvalue(15) imag, random (6.85872455924790447 observed
> vs -6.85872455924790536 expected) [877990]
> FAIL: gen, direct eigenvalue(16) imag, random (-6.85872455924790536
> observed vs 6.85872455924790625 expected) [877992]
>
> I'm using GSL version 1.16, 32-bit Ubuntu 10.04 and GCC 4.4.3.
>
> Best regards,
> Victor
>