def MatT.matvec

bend-tensors@0.0.0.2 · bend_tensors.bend:901

import Base

901# m * v: MatT(r, c) times VecT(c) is VecT(r)
902def MatT.matvec(+r: Nat, +c: Nat, +m: MatT(r, c), +v: VecT(c)) -> VecT(r):
903  match r c:
904    case 0n 0n:
905      MatB{b} = m
906      VecL{x} = v
907      VecL{Blk.matvec(b, x)}
908    case 1n+p 0n:
909      MatR{t, b} = m
910      x y = MatT.matvec(p, 0n, t, v) MatT.matvec(p, 0n, b, v)
911      VecN{x, y}
912    case 0n 1n+q:
913      MatC{l, r2} = m
914      VecN{vl, vr} = v
915      x y = MatT.matvec(0n, q, l, vl) MatT.matvec(0n, q, r2, vr)
916      VecT.add(0n, x, y)
917    case 1n+p 1n+q:
918      MatQ{a, b, c2, d} = m
919      VecN{vl, vr} = v
920      p0 q0 p1 q1 = MatT.matvec(p, q, a, vl) MatT.matvec(p, q, b, vr) MatT.matvec(p, q, c2, vl) MatT.matvec(p, q, d, vr)
921      VecT.add2(p, p0, q0, p1, q1)