Algorithm 3: Environmental Selection

Input: Q , Z , z

Output: P

1: F N o n d o m i n a t e d s o r t ( Q )

2: Last front to be included: F l

3: C P i = 1 l F i

4: if | C P | = N then

5: return P C P

6: else

7: C P i = 1 l 1 F i

8: Points to be chosen from F l : K N | C P |

9: C P F l

10: Normalize objectives: C P F l min ( F l ) max ( F l ) min ( F l )

11: Associate each member s of C P a reference point: A R A s s o c i a t e ( C P , Z )

12: closest reference point: δ s o r t ( A R )

13: return P C P δ K

14: end if