Re: [Bug-gsl] possible bug in GSL

[Brian Gough]

At Tue, 2 Feb 2010 10:14:12 -0500,
Gunjan Verma wrote:
>       I have found a potential bug in GSL, in the "infnan.c" file
> I am building GSL for an embedded system which does not have isnan
> nor IEEE comparisons, so both of those flags are 0 . As a result,
> based on the #if and #elif statements both being false, I believe
> that the function gsl_isnan does not get defined, because I am
> getting "undefined reference to gsl_isnan" being generated by svd.c
> when I try to use the svd .

Thanks for your email.  I can see how that might be a problem. 

From my side, it's not clear how to test for NaN if there is no isnan
function and IEEE comparisons do not work (i.e. if it's not possible
to test for NaN by checking if x!=x).

Is NaN actually supported on this platform and if so how would you
test for it?  

The SVD checks for NaNs to avoid getting into an infinite loop with
bad data.  If you only work with safe matrices it might not be
necessary.

-- 
Brian Gough

GNU Scientific Library -
http://www.gnu.org/software/gsl/