16 replies to this topic

[LunaBlu]

Hello!!
I am a new member and i thought to start immediately with a difficult subject...
I would need a bode and nyquist plot for my casio cfx-9970G... i have looked for them everywhere and i found the bode plot of Rookie (rather, compliment to him!!).
I will try it soon but before that... i would like to know if someone could help me with the nyquist plot. I don't know where to find it, i would make it by myself but unfortunately... at the moment i would not able to do that and i have not much time to study basic programming... so... is there some good idea?? I have found a fantastic nyquist plot here:

http://www.ticalc.or.../345/34599.html

Unfortunately it is for TI model.... is there a way to translate it for CFX? I don't know much about this kind of programming but if someone can help me someway... i would be very grateful. Just a little suggestion could be a great help form me.
Thanks very much, bye bye.

P.S.: oh yes... the 3^ thing where "root locus" but ok... for now nyquist would be enough... Thanks again.

[Andy.Davies]

i cant remember if i have one, but check the AFX > Basic Section of My Site they should be all compatable with the CFX

[LunaBlu]

i cant remember if i have one, but check the AFX > Basic Section of My Site they should be all compatable with the CFX

<{POST_SNAPBACK}>

Hi! Thank you for your help.
Unfortunately i couldn't find a nyquist plot in your basic section... anyway i found other interesting applications so thanks very much.
About nyquist... i am starting thinking i will never find it...
I will keep waiting for some help... Thanks again, bye bye.

[R00KIE]

Nyquist plot can most probably be done for CFX, but only after looking into it more deeply is possible to know if it is really possible.
i've eard about it in classes but like most you learn at classes you never know how or were it can be applied until you need to use it, so i never paid much attention to it but i can take a look and i will post something when i have an answer

[LunaBlu]

[original post]
Hi Rookie!
Yes, you are correct, this kind of applications are not so used. Or better... they are used only for particular subjects, that is because i can find it nowhere...
Anyway, if you can find a solution or something useful... i would be very grateful!!
I will keep waiting for...
Thanks in advice for your help. Bye bye!!
[/original post]

Ehm... the "guest" above was me... sorry but i had forgotten to log in...
Bye bye!!

andy.davies: No worries, posts merged

Edited by Andy.Davies, 31 July 2005 - 01:25 PM.

[R00KIE]

Well i've been taking a look and fighting with it and i think it works well, it can be improved though, but this is more difficult than BODE PLOT, not the concept but coding a fast and efficient solution.
Try this, i will upload it to the file sharing when i finish the user interface (after getting some feedback too):
Nyquist plot
The CFX is a good calculator but when you want to do something cool like a game or more advanced math you hit a wall, so don't forget to read the readme.txt.
You will see debug info on the screen because it's just a "pre release candidate" there is no user interface to change the parameters that affect the program it's just the bare minimum so you (and anyone that cares) can see the end result, that should be just like that, the graph and the calculator's built in tracer, zoom, etc.
if you find any errors or have sugestion to improve the prog say so and i will see if it is feasable.

[LunaBlu]

Hi R00KIE!!!
I have no words, you are great, very compliment for the Nyquist plot!!
I tried it with your f-mem examples and i think it works well but... just a problem... i tried it with some functions of mine but i think it doesn't like them...
I mean... i tried with this one:

(S+1)/(Sx(S-2))

But it doesn't work... it says "Ma error".
I have also tried with this one:

(1+3S)x(1+5S)/(S^2x(1+S))

but again "Ma error".
The same with this one:

(S+1)^2/(S^2x(S-4))

Maybe i am doing something wrong... i don't know...
Anyway compliment again, really. I will keep trying it until it works perfectly.
Thanks for your help, bye bye!!

[R00KIE]

Well that is an half bug, i explain:
the plot starts at frequency=0, and with your functions you get zero at the denominator and because the CFX has no error trapping mecanism you get an error, i can fix this particular issue by changing the initial frequency value to something very small and close to zero but i would not solve the issue beause that can happen at any time, so most probably i will make what i didn't want to, make the user input the numerator and denominator separatetly and check for division by zero and adjust accordingly, i will do that and make a user interface, hopefuly only a very stange equation will cause problems then.

[LunaBlu]

Yes, you are correct, now i understand the problem.
Well... i hope your solution can fix it. And i hope to be never able to find very strange equations...
Ok, i will impatiently keep waiting... i really need this plot and your help is very great. Thanks again for everything!!
Bye bye!!

[R00KIE]

If you want a quick and dirty way to see the graphs (the first one at least) edit the main program and change the line 0->A to 1e-2->A, this will bypass the problem until i fix this issue.

[LunaBlu]

If you want a quick and dirty way to see the graphs (the first one at least) edit the main program and change the line 0->A to 1e-2->A, this will bypass the problem until i fix this issue.

Hi, i am here again!!
Just a quick reply to see if there are news about the nyquist plot.
Rather, i have tried "your quick and dirty way" to see the first graph and... it seems to work so... the solution should not be far.
Thanks again, bye bye!!

[R00KIE]

As i said it's quik and dirty, so the iteration process needs to be reworked and must take various situations into acount, i'm still trying to find the best way to deal with most of them.

[LunaBlu]

As i said it's quik and dirty, so the iteration process needs to be reworked and must take various situations into acount, i'm still trying to find the best way to deal with most of them.

Yes, i understand. Well, no problem, i will keep waiting for.
Thanks, bye bye!

[Overlord]

The program should work on the AFX except that you don't have colors on AFX, so you must change the lines

\S-Gph1 \DrawOn,\xyLine,\List 1,\List 2,1,\Dot,\Orange
\S-Gph2 \DrawOn,\xyLine,\List 1,\List 3,1,\Dot,\Blue
\S-Gph3 \DrawOn,\xyLine,\List 4,\List 5,1,\Dot,\Green

- remove the ,\(color) after 'Dot'
- change the three 'Dot' into one 'Dot', one 'Cross' and one 'Square'

i think the rest is ok

[leighkay]

Hey guys.

Just downloaded and trying to use Rookie's, what could be potentially awesome BODE program.

Only trouble is, im not exactly sure how to enter my Transfer function.

the TF is (S+3)/S(s+1)(s+2). I assume i have to enter it into Y1 equation, but im not sure how. I tried entering it like that listed to the left, but whenever i run i get: SYN ERROR.

Thanks heaps
Leigh
(cfx 9850GB+ is my calc)