introduction matrix.c is_sparse() function error

[mennamorato]

Probably nobody is paying attention to this repo..i was going to try a pull request but its very old.
anyways... is_sparse does not work correctly because the formula is inverted, see here to fix it:

54 //if((matrix.cols * matrix.rows)/zero_elements >= sparse_threshold){ <-- BAD
55 if((zero_elements/(matrix.cols * matrix.rows)) >= sparse_threshold){
return 1;
}else{
return 0;
}

also to get rid of warnings about printf''ing pointers change the %d to %p here:
186 // Attempting to multiply m and n, should work
187 error = matrix_multiply(m,n,&p);
188 printf("&p: %p\n",&p);
189 printf("p: %p\n",p);

[lionleaf]

You're right, I didn't expect any pull requests on this. Nice find though!

It's an old repo with code I'm no longer using, but if you want to submit it as a pull request I'm happy to merge it