Experiment with matrix multiplication and dot product

matrix.ml

let transpose A = 
  let new_mat = Array.make_matrix (Array.length A.(0)) (Array.length A) 0 
  in
  for y = 0 to (Array.length A) - 1 do
    for x = 0 to (Array.length A) - 1 do
      new_mat.(y).(x) <- A.(x).(y)
    done
  done;
  new_mat
in
let dot_of_vecs a b = 
  let sum = ref 0 in 
  for n = 0 to (Array.length a) - 1 do
    sum := !sum + (a.(n) * b.(x))
  done; 
  !sum
in
let product_of A B =
  let init_mat = Array.make_matrix (Array.length A) (Array.length (transpose B)) 0 in
  for y = 0 to (Array.length (transpose B)) - 1 do
    for x = 0 to (Array.length A) - 1 do
      init_matrix.(x).(y) <- dot_of_vecs A.(x) (transpose B).(y)
    done
  done;
  init_mat
in
let some_product_of A B =
  if Array.length A <> Array.length B.(0) then None 
  else Some(product_of A B)
in
match some_product_of X X with
| Some sqrt_x -> true
| _ -> false