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## Re: Derivative function

 From: A S Hodel Subject: Re: Derivative function Date: Wed, 19 Feb 2003 12:58:21 -0600

The octave controls toolbox is a part of Octave; the simulation language used in this lecture notes series is, unfortunately, not available for public use (export controlled). I originally used these notes in 6-month "short" course at Marshall Space Flight Center. The simulation language is a NASA - internal simulation tool that I used to obtain linearizations. This is the source of the syntax confusion. The MSFC simulation tool was used to obtain LTI dynamic models that were loaded into octave data structures
```(see functions tf2sys, ss2sys, zp2sys, etc.).

```
I've thought about writing a translator to convert a differential equations list (such as that in my examples) to Octave code (m-file or .oct file). I'm making some progress on some
```other areas, but it's also export controlled, so I can't put it out.

It would be great to have some simulink-like capability to:
```
(1) easily describe dynamic systems (in either block diagram or differential/difference
```     equation form, and
```
(2) obtain linearizations from these dynamic system descriptions. These linearizations
```   become the [a,b,c,d] matrices in the octave controls toolbox.

Wish lists: they're not just for Christmas anymore.

On Wednesday, February 19, 2003, at 12:45 PM, Henry F. Mollet wrote:

```
```I have just looked at the lecture notes by A. Scottedward Hodel on
```
Introductory Controls Using the Octave Control Systems Toolbox. The example of the damped mass-spring system on p. 19/20 is implemented, among other
```code with the following code line:
: pos-x'' = (1.0/mass) * (......... - pos_x) - alpha*pos_x'
Where pos_x and first and second derivative of pos_x appear.

```
Question: Is the Octave Control Systems Toolbox different from Octave and
```can it be considered a symbolic math package?

Question: if pos_x' is the derivative, how is it distinguished from the
```
complex conjugate transpose operator " ' "? (Transpose operator is " .' "
```
```
A. S. Hodel, Assoc. Prof, Dept. Elect & Comp Eng, Auburn University, AL 36849-5201 (334) 844-1854 200 Broun Hall address@hidden http://www.eng.auburn.edu/~scotte
```

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