Help on plot 3 roots for each variable and connecting them

I'm trying to plot the roots coming out of the this code but after I Run the code, no graph shows up. I know that for each variable K_p_no, there's 3 roots because the pol variable shows up in the Workspace with 3 roots in a single cell. How can I find the roots of the equation and plot them all in the same graph? If possible, also connect them. This is for a PID controller but without the ID, if it helps in any way.

clc; clear all; close all;
n = 10;
K_p_neg_inf = -1000;
K_p_pos_inf = 1000;
K_p_no = K_p_neg_inf:n:K_p_pos_inf;
for i=1:length(K_p_no);
    ChEq{i} = [K_p_no(i)*50 K_p_no(i)*100 1 K_p_no(i)*60]; %characteris eqn (K_p*50*s^2 + K_p*100*s + s^2 + K_p*60) of the T_s, set =0 to find the poles in the s-plane
    pol{i} = roots(ChEq{i}); %poles on s-plane
    
    plot(real(poles), imag(poles), 'rx')
    xlabel('Real Axis (seconds^-1)');
    ylabel('Imaginary Axis (seconds^-1)')
    grid on
end

Answer 1

[Star Strider]

See if this slightly edited version of your code does what you want:

n = 10;
K_p_neg_inf = -1000;
K_p_pos_inf = 1000;
K_p_no = K_p_neg_inf:n:K_p_pos_inf;

figure
hold on
for i=1:length(K_p_no);
    ChEq{i} = [K_p_no(i)*50 K_p_no(i)*100 1 K_p_no(i)*60]; %characteris eqn (K_p*50*s^2 + K_p*100*s + s^2 + K_p*60) of the T_s, set =0 to find the poles in the s-plane
    pol{i} = roots(ChEq{i}); %poles on s-plane
    
    plot(real(pol{i}), imag(pol{i}), 'rx')
    xlabel('Real Axis (seconds^-1)');
    ylabel('Imaginary Axis (seconds^-1)')
end
hold off
grid

.

[Franz Adam Magallanes]

It is what I'm looking for code-wise. The values are resulted are really really close to each other which makes the graph look like it only plotted one. The equation provided by my professor was incorrect.

Thanks for the coding help!

[Star Strider]

As always, my pleasure!