shuffle an array

double **select_subpool(Params *p, double **pool,int nrows,int nrows_sub)
{
    int positions[nrows];
    for(int i = 0 ; i < nrows ; ++i) positions[i] = i;

    // shuffle the vector
    //-------------------
    knuth_shuffle((void*)positions, nrows, p->rng, sizeof(int*));
    for (int i = 0 ; i < nrows ; ++i) printf("%d\t",positions[i]);
    printf("\n");
}

It's sizeof(int).

BTW if you name the file with a .c extension gist will add syntax highlighting.

The code from facilication.c (line 64) is also broken. It works simply because, in many cases, sizeof(double*) returns 8, just like sizeof(double), but it might not be true for all computers (the size of pointers vary).

Ok, I applied the method for a matrix shuffle (that's why I put the *).
I will removed the star in facilitation too.
Thanks