A general visualisation script for MNIST and CIFAR dataset

readme.md

VisualModule

Visualize image dataset. Currently support MNIST and CIFAR10. visualize_dataset takes 2 arguments:

1. imgs of type Dense.Ndarray.D.arr,
2. len, of type int, for showing lenxlen images sample from the imgs

visualModule.ml

#!/usr/bin/env owl

open Owl

let visualize_dataset x len  = 
  assert( len > 1 && len < 100 ); 
  let num = len * len in 
  let mats = Array.make num (Dense.Matrix.D.zeros 1 1) in

  for i = 0 to num - 1 do 
    let fig = Dense.Ndarray.D.get_slice_simple [[i];[];[]] x 
              |> Dense.Ndarray.D.squeeze
              |> Dense.Matrix.D.of_ndarray
    in 
    mats.(i) <- fig;
  done;

  let mats2 = Array.make len (Dense.Matrix.D.zeros 1 1) in
  for i = 0 to (len-1) do 
    let m = Array.sub mats (i*len) len 
            |> Dense.Matrix.D.concatenate ~axis:0 
    in
    mats2.(i) <- m 
  done;

  let img = Dense.Matrix.D.concatenate ~axis:1 mats2 in 
  Plot.image img

(*
let x, _, _ = Dataset.load_cifar_test_data () in 
let x = Dense.Ndarray.Generic.cast_s2d x 
        |> Dense.Ndarray.D.slice [[];[];[];[0]]
        |> Dense.Ndarray.D.squeeze
in 
visualize_dataset x 10
*)