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Re: pole/zero plot for TransferFunctionModel in the control system package?

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  • Subject: [mg125436] Re: pole/zero plot for TransferFunctionModel in the control system package?
  • From: Suba Thomas <subat at wolfram.com>
  • Date: Wed, 14 Mar 2012 00:35:31 -0500 (EST)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com

That is a good candidate for a Properties and Relations example.

If you just want the open-loop poles and open-loop zeros, RootLocusPlot 
could be made more efficient.

RootLocusPlot[
 k*((s^2 + 2*s + 4)/(s*(s + 4)*(s + 6)*(s^2 + 1.4*s + 1))), {k, 0, 1},
  Method -> "GenericSolve", PlotStyle -> None,
 PoleZeroMarkers -> {Automatic, None, Automatic}, PlotPoints -> 2,
 MaxRecursion -> 0, PlotRange -> All]

Suba Thomas
Wolfram Research


Bob Hanlon wrote:
> Using RootLocusPlot the open - loop poles, closed - loop poles, and
> open - loop zeros are marked using "\[FilledSmallCircle]", "*", and
> "\[SmallCircle]", respectively
>
> RootLocusPlot[k*((s^2 + 2*s + 4)/
>         (s*(s + 4)*(s + 6)*
>            (s^2 + 1.4*s + 1))),
>    {k, 0, 150}]
>
>
> Bob Hanlon
>
> On Mon, Mar 12, 2012 at 5:07 AM, Nasser M. Abbasi <nma at 12000.org> wrote:
>   
>> I was looking at the functions in the control systems, which
>> were added in V 8, and there seems to be a missing an important
>> plot function to generate automatically a map of the locations
>> of the poles and zeros for a transfer function (continuous or
>> discrete time).
>>
>> Unless I overlooked it, I hope this will be added in V 9.
>>
>> I know I can generate such a plot myself by some extra coding,
>> but I think a build-in function to do this would be a better solution
>> similar to all the other useful standard control systems plot functions
>> listed here
>>
>> http://reference.wolfram.com/mathematica/guide/ClassicalAnalysisAndDesign.html
>>
>> Another software has this function as standard in their control
>> systems toolbox and it is called pzmap (for googling and
>> reference to what this command do).
>>
>> thanks,
>> --Nasser
>>
>>
>>     
>
>
>
>   



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