some changes from visit at Austin

main.h

@@ -11,7 +11,7 @@
 #define ERROR(condition, msg, ...) if(condition){fprintf(stderr, msg, ##__VA_ARGS__); exit(1);}
 #define LOOP(i) for(int i = 0; i < 3; i++)
 
-#define NUM_GROUP_ELEMENTS 50000
+#define NUM_GROUP_ELEMENTS 10000
 
 typedef struct {
 	double x[3];