One program is not running after differentiation

Locate the problem and suggest for correction:

clear all; clc;

%%%%% parameter declaration %%%

g1 = 10^(-4);

g2 = 6;

g3 = 0.66;

g4 = 0.08;

dp = 0;

dc = 0;

d3 = 0;

d4 = 0;

rv = 2.5;

r1 = 12;

k02 = 200;

k04 = 0.01*k02;

c = 1;

% Main Part %

syms om rc real

f1 = om + dp - dc + 1i*g1;

f2 = om + dp + 1i*g2;

f3 = om + dp + d3 + 1i*g3;

f4 = om + dp + d3 + d4 + 1i*g4;

M = (f1*f2 - rc^2)*(f3*f4 - rv^2) - f1*f4*r1^2;

Fp = -((f3*f4 - rv^2)*f1*k02)/M;

Fm = -((M + (f1*f2 - rc^2)*rv^2)*k04)/(M*f4);

G = (f1^2*r1^2*rv^2*k02*k04)/M^2;

kp = (om/c) + 0.5*(Fp + Fm) + sqrt((0.5*(Fp + Fm))^2 + G);

% Define Grn as a function of rc by differentiating kp w.r.t. only om (not by rc) and putting om = 3

Grn = @(rc) double((1/c)*(real(diff(subs(kp, om, 3), om))));

% Define range of rc values

rc_values = linspace(0, 10, 100);

% Evaluate Grn for each rc value

Grn_values = arrayfun(Grn, rc_values);

% Plot Grn versus rc

plot(rc_values, Grn_values, 'LineWidth', 1.5, 'Color', 'r');

xlabel('rc');

ylabel('Grn');

title('Grn versus rc');

Answer 1

[Torsten]

clear all; clc;
%%%%% parameter declaration %%%
g1 = 10^(-4);
g2 = 6;
g3 = 0.66;
g4 = 0.08;
dp = 0;
dc = 0;
d3 = 0;
d4 = 0;
rv = 2.5;
r1 = 12;
k02 = 200;
k04 = 0.01*k02;
c = 1;
% Main Part %
syms om rc real
f1 = om + dp - dc + 1i*g1;
f2 = om + dp + 1i*g2;
f3 = om + dp + d3 + 1i*g3;
f4 = om + dp + d3 + d4 + 1i*g4;
M = (f1*f2 - rc^2)*(f3*f4 - rv^2) - f1*f4*r1^2;
Fp = -((f3*f4 - rv^2)*f1*k02)/M;
Fm = -((M + (f1*f2 - rc^2)*rv^2)*k04)/(M*f4);
G = (f1^2*r1^2*rv^2*k02*k04)/M^2;
kp = (om/c) + 0.5*(Fp + Fm) + sqrt((0.5*(Fp + Fm))^2 + G);
% Define Grn as a function of rc by differentiating kp w.r.t. only om (not by rc) and putting om = 3 
Grn = 1/c*real(subs(diff(kp,om),om,sym('3')));
fplot(Grn,[0 25],'LineWidth', 1.5, 'Color', 'r');
xlabel('rc')
ylabel('Grn')
title('Grn versus rc')

[Pradipta Panchadhyayee]

Thanks. It works.

[Pradipta Panchadhyayee]

Thank you again. It helps me a lot. Please see my other posts where I need help.