Models — Row by Column

dotc    ← {↑ (↓⍺) ∘.(⍺⍺{⍺⍺/⍺ ⍵⍵ ⍵}⍵⍵) ↓(¯1⌽⍳⍴⍴⍵)⍉⍵}
dotc1   ← {↑ (↓⍺) ∘.(⍺⍺{⍺⍺/⍺ ⍵⍵ ⍵}⍵⍵) ↓flip ⍵}
dotc2   ← {↑ (↓⍺) ∘.(⍺⍺/at ⍵⍵) ↓flip ⍵}
dotc3   ← {↑ ⍺ ∘.(⍺⍺/at ⍵⍵)compose↓ flip ⍵}

flip    ← {(¯1⌽⍳⍴⍴⍵)⍉⍵}
at      ← {⍺⍺(⍺ ⍵⍵ ⍵)}
compose ← {(⍵⍵ ⍺)⍺⍺(⍵⍵ ⍵)}