nn.InstanceNorm2d, how to decide the num_features parameter?

As the topic says, I don’t understand how to decide the num_features from the doc, is it a number which can be randomly picked?
Thank you.

it is the number of channels of your input to InstanceNorm2d.

If your input will be Tensor of size: 2 x 3 x 4 x 5 then num_features should be 3