I am trying to find the dominant poles without using a for loop...

This is what I have so far, and it is driven by the fact my professor says he does not want to see overly similar code as the others in my class... But I dont know how to find the dominant poles from this without a for loop like so many of my classmates will have... Any Ideas?

num=[3 3];

den=[conv([1 0],[conv([1 4],[1 7])])]

Gs1=tf(num,den)

hold on

rlocus(Gs1)

GS1=zpk(Gs1)

%%

R=[-0.1:-0.3:-5.8];

I=i*[0.01:0.01:0.5];

[Re Im]=meshgrid(R,I);

p=Re+Im;

p_s=sort(p);

%% angle from double pole at zero

Theta=180-angle(p);

Ts=sort(Theta);

%% distances from -7 to possible poles on Re axis

P4=-7;

P4d=P4-real(p_s(1,1:20));

%% distances from -4 to possible poles on Re axis

P3=-4;

P3dA=P3-real(p_s(1,1:13));

P3dO=real(p_s(1,15:20))-P3;

P3d=[P3dA,0,P3dO];

%% distance from zero poles to prime pole possible

P1_2=real(p_s);

%% Angles from "dP" to -4

ThP3A=atan2(imag(p_s(1:50,1:13)),P3dA);

ThP3O=180-atan2(imag(p_s(1:50,15:20)),P3dO);

ThP390=90*ones(1,50)';

ThP3=[ThP3A,ThP390,ThP3O];

%% Angles from "dP" to -7

ThP4=180-atan2(imag(p),P4d);

%% Finding Angle Deficiencies

ANGDef=180-ThP4-ThP3-2*Ts;

AngN=ANGDef/2;

xprime=1./tan(180-AngN);

x=[0:-.3:-5.8];

a_val1=x+xprime

Answer 1

[Raunak Gupta]

Hi,

I don’t see any for loop in the code that is provided with the question, however if there is a for loop you can always write the code using array indexing so that you will be dealing vector in a matrix rather than going in a for loop. Array indexed code is also faster than the for loop one. You may find following article and documentation useful.

Matrix Indexing in MATLAB

Array Indexing