I was reading http://pytorch.org/docs/master/nn.html#conv1d 657 to understand 1D convolutions and I was trying to understand when would the in_channels not equal to 1.
If we have say a 1D array of size 1 by D and we want to convolv it with a F=3 filters of size K=2 say and not skipping any value (i.e. stride=1), would the code be:
F,K=3,2
m = nn.Conv1d(1, F, K, stride=1)

I am just not sure when the in_channels would not be 1 for a 1D convolution. Furthermore, assuming it is possible for it to not be 1, does it mean when its not one? Is it not 1 when there are lots of 1D strips we are considering, say in a data set of size N (though not sure what that type of data set would mean…)