How can I call an array of letters into a for loop?

I would like to setup this for loop to output each interation of with the coorasponding part of my homework. I can do it all individually but that doesn't seem efficient. Every way I have tried outputs to cooresponding integer and not the actual character (a,b,c,d)

I would like it to read:

The open loop poles for part c are:

ans =

0

-10

-10

Closed loop system is stable for part c.

Gain Margin for part c is: 20.000000.

Phase Margin part c is: 78.689008.

Time delay Margin for part c is: 1.386851.

k = [200 100 100 80];

a = [1 1 0 1];

z = [1 0.1 1 1];

w = 10;

s = tf('s');

C = [65 66 67 68];

letters = char(C)

for i=1:4

L = k(i)/ ((s+a(i))*(s^2 + 2*z(i)*w*s + w^2));

[top, bottom] = tfdata(L);

fprintf('The open loop poles for part %f are:\n', letters(i))

roots(bottom{1})

marg = allmargin(L);

if marg.Stable == 1

fprintf('Closed loop system is stable for part %f.', letters(i))

fprintf('\n\n')

else

fprintf('The closed loop system is not stable for part%f.', letters(i))

fprintf('\n')

end

fprintf('Gain Margin for part %f is: %f.\n', letters(i) , marg.GainMargin)

fprintf('Phase Margin for part %f is: %f.\n', letters(i) , marg.PhaseMargin)

fprintf('Time delay Margin for part %f is: %f.\n\n', letters(i) , marg.DelayMargin)

end

Answer 1

[Paul]

If I understand the question ....

letters = 'ABCD';  % simpler
for ii = 1:4
fprintf('The open loop poles for part %s are:\n', letters(ii))  % use s not f as the format
end

The open loop poles for part A are:
The open loop poles for part B are:
The open loop poles for part C are:
The open loop poles for part D are:

[Patrick Scott]

You are amazing. Thank you very much!