9/22 第二次讀書會（Chapter 2）現場提問 在 ["A First Look at a Neural Network"](https://github.com/fchollet/deep-learning-with-python-notebooks/blob/master/2.1-a-first-look-at-a-neural-network.ipynb) note book 中，為何要將所有的灰階像素除以 255？(code example 如下)？ ``` train_images = train_images.reshape((60000, 28 * 28)) train_images = train_images.astype('float32') / 255 test_images = test_images.reshape((10000, 28 * 28)) test_images = test_images.astype('float32') / 255 ```
9/22 第二次讀書會（Chapter 2）現場提問
在 "A First Look at a Neural Network" note book 中，為何要將所有的灰階像素除以 255？(code example 如下)？