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The root locus part of the Control Systems program in this forum does not work.
I wrote a little script that can generate the root locus of a system, with instructions on how to plot.
With thanks to members @ThomasA and @Tim Wessman for suggestions on how to properly plot it.
Here is the code:

Code:

// This is a script to find the root locus of system

// Arguments are num, den coefficients of polynomial

// Stepp is the size of the change in K

// Endd is the max value that K takes

// Example:  rls([1,3],[1,7,14,8,0],0.01,10)

// To use this program:

// In the Statistics 2var, symbolic

// Set independent varibale to L0

// Set dependent variable to L1

// Plot

EXPORT rls(num, den, stepp, endd)

BEGIN

LOCAL begg;

LOCAL xv:={};

LOCAL yv:={};

begg:=0.0001;

FOR K FROM begg TO endd STEP stepp DO

xv := concat(xv, RE(POLYROOT(poly2symb(den)+K*poly2symb(num))));

yv := concat(yv, IM(POLYROOT(poly2symb(den)+K*poly2symb(num))));

END;

L0:= xv;

L1 := yv;

END;

Inside CAS, point(proot(polynomial)) will display the list of roots of a polynomial. For several polynomials you can create an empty list l and run l:=concat(l,(proot(..)) inside the loop and run point(l) after the loop.

(11-29-2018 08:41 AM)parisse Wrote: [ -> ]Inside CAS, point(proot(polynomial)) will display the list of roots of a polynomial. For several polynomials you can create an empty list l and run l:=concat(l,(proot(..)) inside the loop and run point(l) after the loop.

That works better, thanks!

Code:

// This is a script to plot the root locus of a system

// Arguments are num, den coefficients of polynomial

// Stepp is the size of the change in K. If the script runs too slow, increase the stepp size. 

// Endd is the max value that K takes, if it is too slow to plot, decrease the max value. 

// Example:  rlscas([1,3],[1,7,14,8,0],0.01,10)

#cas

rlscas(num,den,stepp,endd):=

BEGIN

LOCAL K, begg, l:={};

begg:=0.001;

FOR K FROM begg TO endd STEP stepp DO

l := concat(l, proot(poly2symb(den)+K*poly2symb(num)));

END;

point(l);

END;

#end

It surprisingly works on the PC emulator but not on the physical calculator!!

Error: Execute evaluator not recursive

Take a look what I've got on the calc:

[Image: IMG-5685.jpg]

But in the emulator It runs nicely, I don't know why.

rushfan

parisse

rushfan

chandlerkc

chandlerkc