var data1 = [
  [0,0,0],
  [0,1,1],
  [1,0,1],
  [1,1,0] 
]

print(ml.preprocess(data1,'io',{target:2}))

var data2 = {
  x: [
    [0,0],
    [0,1],
    [1,0],
    [1,1]
  ],
  y: [
    0,
    1,
    1,
    0
  ]
}

print(ml.preprocess(data2,'io',{}))

var data3 = [
  { a:0, b:0, y: 0 },
  { a:0, b:1, y: 1 },
  { a:1, b:0, y: 1 },
  { a:1, b:1, y: 0 },
]

print(ml.preprocess(data3,'io',{features:['a','b'],target:'y'}))