Brian Actually, I did not know what "IEEE" Comparisons were. I had to manually write the "configure.h" file since I could not build gsl on the system directly. As a result, I set that flag (and the isnan, which I surely did not have since I checked it on the target system ) to 0. I was able to build GSL but had problems with gsl_isnan not being defined at run time.
Subsequently, I did find that IEEE comparisons worked and set this flag to 1 in configure.h. Now all is well. I guess the end result of this is that I still feel there is a "logical" gap in that the GSL runtime assumes the presence of gsl_isnan , but there is a theoretical possibility at least, that it does not get defined at build time (if both flags are 0). I think the solution to close this gap would be to refuse to build GSL if both "have_isnan" and "have_ieee comparisons" are set to 0. Practically, I do understand that this is not really an issue . This is more for just logical correctness than anything else. Once again, thanks for your work on GSL and for your timely replies - it is truly a fantastic product! Gunjan On Tue, Feb 9, 2010 at 12:15 PM, Brian Gough <[email protected]> wrote: > 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/ > _______________________________________________ Bug-gsl mailing list [email protected] http://lists.gnu.org/mailman/listinfo/bug-gsl
