4 void c_minx(DCELL * result, DCELL * values, 
int n, 
const void *closure)
 
   12     for (i = 0; i < 
n; i++) {
 
void G_set_d_null_value(DCELL *dcellVals, int numVals)
 
void c_minx(DCELL *result, DCELL *values, int n, const void *closure)
 
int G_is_d_null_value(const DCELL *dcellVal)
Returns 1 if dcell is NULL, 0 otherwise. This will test if the value dcell is a NaN. Same test as in G_is_f_null_value().