[SciPy-Dev] Proposal: calling signal.lti object returns transfer function value

Juan Luis Cano juanlu001@gmail....
Tue Jul 16 09:49:57 CDT 2013

Hello all,

I've been trying the scipy.signal module lately for some easy things and 
I had an idea, but I thought it would be better to bring it up in the 
mailing list before filing a PR on GitHub.

My proposal is to implement the __call__ method on signal.lti objects so 
it returns the value on the transfer function.

I took the idea from the `bode` function. This line:

     y = numpy.polyval(sys.num, jw) / numpy.polyval(sys.den, jw)


could be moved to signal.lti.__call__, and then in `bode` write

     y = sys(jw)

The detail is trivial (so is the implementation) but I think it would be 
a useful thing. What do others think? Shall I open a pull request?

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