converttomultiarray.swift

func generateMultiArrayFrom(image: UIImage) -> MLMultiArray? {
  guard let data = try? MLMultiArray(shape: [8,8], dataType: .double) else {
    return nil
  }
        
  let hTileWidth = image.size.width / 8
  let vTileWidth = image.size.height / 8
        
  var xPos : CGFloat = 0
  var yPos : CGFloat = 0
        
  for rowIndex in 0...7 {
    for colIndex in 0...7 {
      //cut the image part at the certain coordinates
      let imageRect = CGRect(x: xPos, y: yPos, width: hTileWidth, height: vTileWidth)
      let cutImage = image.crop(rect: imageRect)
      let avgColor = cutImage.areaAverage()
      var grayscale: CGFloat = 0
      var alpha: CGFloat = 0
      
      avgColor.getWhite(&grayscale, alpha: &alpha)          
      xPos += hTileWidth
      
      let alphaAsNumber = NSNumber(integerLiteral: Int(alpha * 16.0))
      data[rowIndex*8 + colIndex] = alphaAsNumber
    }
    xPos = 0
    yPos += vTileWidth
  }
  return data
}