Normalization in the mnist example

@lkins, @smth
why you guys said [-1,1]? From the document, I just see [0,1]
http://pytorch.org/docs/master/torchvision/transforms.html

class torchvision.transforms.ToTensor

Converts a PIL Image or numpy.ndarray (H x W x C) in the range [0, 255] to a torch.FloatTensor of shape (C x H x W) in the range [0.0, 1.0].

So if I do the normalization on each channel by myself, to convert [a,b] to [0,1], I don’t need transforms.ToTensor anymore, right?

But what if my data has a different range of each channel, such as x: -10 ~ 10, y: 1 -100, z: 20 -25 (actually they have some hidden correlation between each other), how to normalization? It doesn’t make sense to normalize them to the same range.