[Bug-gsl] sorting vectors with NANs

[Ben Klemens]

Dear GSL maintainers,

If there's an NAN in a vector, then gsl_sort_vector falls into an
infinite loop.

Run the program below as is, and it will never exit. If you comment out
the GSL_NAN line, then it exits in the blink of an eye.

I've tried this on two Linux boxes, both running Mandrake 10, one with
GSL 1.6 and one with GSL 1.5. Compiled with:
gcc -lgsl -lgslcblas bug_demo.c


Thanks,


BK


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#include <gsl/gsl_matrix.h>
#include <gsl/gsl_sort_vector.h>
#include <gsl/gsl_math.h>
 
int main(void){
gsl_vector      *v      = gsl_vector_calloc(3);
        gsl_vector_set(v, 0, GSL_NAN);
        gsl_vector_set(v, 1, 1);
        gsl_vector_set(v, 2, 2);
        gsl_sort_vector(v);
        return 0;
}

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ps. A bug report is probably not the place to put this, but I'm putting
together a stats library based on the GSL. If anybody's interested,
have a look at apophenia.info (which is still in the planning stage).