[SciPy-user] signal.lti

Stefan van der Walt stefan at sun.ac.za
Tue Sep 12 03:37:14 CDT 2006


On Tue, Sep 12, 2006 at 07:04:06AM +0200, Lars Friedrich wrote:
> > >I thought about this over the weekend.  I was wrong about the matrices
> > >not being correct.  The A matrix really is just 0.  So, passing in the
> > >numerator and denominator polynomials does correctly create a system,
> > >you just can't take its step response.
> 
> shouldn't signal.lsim2 be able to handle such systems? I tried the
> following:
> 
> #*************** start shell session
> from scipy import signal
> from numpy import *
> 
> sys1=signal.lti((1),(1,0))
> 
> signal.lsim2(sys1, ones(10), arange(10))
> 
> Traceback (most recent call last):
>   File "<input>", line 1, in ?
>   File "/usr/lib/python2.4/site-packages/scipy/signal/ltisys.py", line
> 333, in lsim2
>     ufunc = interpolate.linear_1d(T, U, axis=0, bounds_error=0,
> fill_value=0)
> AttributeError: 'module' object has no attribute 'linear_1d'
> #***************** end shell session

Should be fixed in SVN now.

Cheers
Stéfan


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