[SciPy-User] bug in signal.lsim2
Thu Jan 28 15:05:53 CST 2010
On Thu, Jan 28, 2010 at 3:39 PM, Ryan Krauss <email@example.com> wrote:
> I believe I have discovered a bug in signal.lsim2. I believe the
> short attached script illustrates the problem. I was trying to
> predict the response of a transfer function with a pure integrator:
> G = -------------
> to a finite width pulse. lsim2 seems to handle the step response just
> fine, but says that the pulse response is exactly 0.0 for the entire
> time of the simulation. Obviously, this isn't the right answer.
> I am running scipy 0.7.0 and numpy 1.2.1 on Ubuntu 9.04, but I also
> have the same problem on Windows running 0.7.1 and 1.4.0.
When I add a small noise
u2 = zeros(N) + 1e-14
u2[:50] = amp
u2[50:200] = amp
it seems to work.
This might be a tricky bug.
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