[SciPy-user] signal.lti

Lars Friedrich lfriedri at imtek.de
Tue Sep 12 00:04:06 CDT 2006


Hello,

> Ryan Krauss 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

What about this error? I get the same errror with
sys=signal.lti((1),(1,1)).

Thanks
Lars



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