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Thread Subject:
Graphing Step Response Error

Subject: Graphing Step Response Error

From: Adam Thompson

Date: 8 Feb, 2009 19:25:03

Message: 1 of 3

I'm trying to graph the step response of a control system, but when I go to plot it, I'm receiving this error:

??? Input argument "hFig" is undefined.

Here's my code:

--
H1 = tf(25, [1 3 25])
step(H1)
--

Thanks for the help!

Subject: Graphing Step Response Error

From: Joerg Buchholz

Date: 9 Feb, 2009 13:33:01

Message: 2 of 3

"Adam Thompson" <awthomp@clemson.edu> wrote in message <gmnbif$24l$1@fred.mathworks.com>...
> I'm trying to graph the step response of a control system, but when I go to plot it, I'm receiving this error:
>
> ??? Input argument "hFig" is undefined.
>
> Here's my code:
>
> --
> H1 = tf(25, [1 3 25])
> step(H1)
> --
>
> Thanks for the help!

The code is correct. I would quit and restart Matlab. If that does not help, I would reinstall Matlab.

Subject: Graphing Step Response Error

From: Steven Lord

Date: 10 Feb, 2009 18:11:28

Message: 3 of 3


"Adam Thompson" <awthomp@clemson.edu> wrote in message
news:gmnbif$24l$1@fred.mathworks.com...
> I'm trying to graph the step response of a control system, but when I go
> to plot it, I'm receiving this error:
>
> ??? Input argument "hFig" is undefined.

What's the full text (including the stack) of the error message? What code
(and what line of that code) is throwing this error?

> Here's my code:
>
> --
> H1 = tf(25, [1 3 25])
> step(H1)

Set a breakpoint on the line where you call STEP and step into the STEP
function using the debugger, to make sure that you're calling the correct
STEP function.

--
Steve Lord
slord@mathworks.com

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