introduction to pytorch in [ ] torch flatten(astart_dim= in [ ] out[ ]tensor([[[ ][ ]][[ ][ ]]]in [ ] shape out[ ]torch size([ ]in [ ] torch flatten(astart_dim= in [ ] out[ ]tensor([[[[ ][ ]][[ ][ ]]][[[ ][ ]][[ ][ ]]]]in [ ] shape out[ ]torch size([ ]the gather method allows us to extract values from tensor along given dimension at given positions listing - illustrates extracting values from tensor using gather