def col_min.go

unified-nsga-iii@0.2.2.0 · normalization.bend:35

import Base
import unified-nsga-iii@0.2.2.0/individual.bend as Ind
import unified-nsga-iii@0.2.2.0/util.bend as Util

35# Column min/max are associative. Mid-split then vec_min / vec_max.
36def col_min.go(+fuel: Nat, pop: List<&2, Ind.Individual>) -> List<&2, F32>:
37  match fuel pop:
38    case 0n Nil{}:
39      Nil{}
40    case 0n ind <> xs:
41      Util.vec_min(Ind.objectives(ind), col_min.go(0n, xs))
42    case 1n+p Nil{}:
43      Nil{}
44    case 1n+p ind <> Nil{}:
45      Ind.objectives(ind)
46    case 1n+p h <> t:
47      +all = {h <> t : List<&2, Ind.Individual>}
48      +mid = Nat.div(Util.list_len(Ind.Individual, all), 2n)
49      lo hi = col_min.go(p, List.take(&2, Ind.Individual, all, mid)) col_min.go(p, List.drop(&2, Ind.Individual, all, mid))
50      Util.vec_min(lo, hi)