sort(array,size,num)
float *array;
{
	/* find num largest objects in array[], return as first[] 
	   num objects in array[], with original order. */
	int *order;
	order = (int *)malloc(num*sizeof(int));
	for(i=0,j=0; i<size; i++) {
		if(array[i] > array[order[j]]) {
			array[order[j++]] = array[i];