I couldn't understand the problem in it? and I did't know where I should put the "o" ?

clc
ti = 0;
tf = 1E-3;
tspan=[ti tf];
P = 1.27;
a = 0.1;
tc = 230E-6;
tp = 5.4E-9;
o = rand(1,5)*100E3;
k = 1E-3;
k1 = k;
k2 = k;
k3 = k;
k4 = k;
k5 = k;


f = @(t,y) [  
                            (P - y(1).*((abs(y(6)))^2 +1))./tc; 
                            (P - y(2).*((abs(y(7)))^2 +1))./tc; 
                            (P - y(3).*((abs(y(8)))^2 +1))./tc; 
                             (P - y(4).*((abs(y(9)))^2 +1))./tc; 
                              (P - y(5).*((abs(y(10)))^2 +1))./tc;

         (y(1)-a).*((y(6))./tp) + (k1./tp).*(y(7)).*cos(y(11)) + (k5./tp).*(y(10))*cos(y(15));
         (y(2)-a).*((y(7))./tp) + (k2./tp).*(y(8)).*cos(y(12)) + (k1./tp).*(y(6))*cos(y(11));
         (y(3)-a).*((y(8))./tp) + (k3./tp).*(y(9)).*cos(y(13)) + (k2./tp).*(y(7))*cos(y(12));
         (y(4)-a).*((y(9))./tp) + (k4./tp).*(y(10)).*cos(y(14)) + (k3./tp).*(y(8))*cos(y(13));
         (y(5)-a).*((y(10))./tp) + (k5./tp).*(y(9)).*cos(y(14)) +(k4./tp).* (y(6))*cos(y(15));

o(1,1) - (k1./tp).*(y(6)/y(7)).*(sin(y(11))) - (k1./tp).*(y(10)/y(6)).*(sin(y(11))) + (k2./tp).*(y(8)./y(7))*sin(y(12)) + (k5./tp).*(y(10)/y(6)).*sin(y(15));
 o(1,2) - (k2./tp).*(y(7)/y(8)).*(sin(y(12))) - (k2./tp).*(y(8)/y(7)).*(sin(y(12))) + (k3./tp).*(y(9)./y(8))*sin(y(13)) + (k1./tp).*(y(6)/y(7)).*sin(y(11));
o(1,3) - (k3./tp).*(y(8)/y(9)).*(sin(y(13))) - (k3./tp).*(y(9)/y(8)).*(sin(y(13))) + (k4./tp).*(y(10)./y(9))*sin(y(14)) + (k2./tp).*(y(7)/y(8)).*sin(y(12));
 o(1,4) - (k4./tp).*(y(9)/y(10)).*(sin(y(14))) - (k4./tp).*(y(10)/y(9)).*(sin(y(14))) + (k5./tp).*(y(6)./y(10))*sin(y(15)) + (k3./tp).*(y(8)/y(9)).*sin(y(13));
o(1,5) - (k5./tp).*(y(10)/y(6)).*(sin(y(15))) - (k5./tp).*(y(6)/y(10)).*(sin(y(15))) + (k1./tp).*(y(7)./y(6))*sin(y(11)) + (k4./tp).*(y(9)/y(10)).*sin(y(14));
                
                                    
                                      ];



[time,Y] = ode45(f,tspan./tp,[0; 0; 0; 0; 0; 1; 1; 1; 1; 1; 0.01; 0.01; 0.01; 0.01; 0.01],o);

Error using vertcat
Dimensions of arrays being concatenated are not consistent.

Error in solution (line 18)
f = @(t,y) [

Error in odearguments (line 92)
f0 = ode(t0,y0,args{:}); % ODE15I sets args{1} to yp0.

Error in ode45 (line 107)
odearguments(odeIsFuncHandle,odeTreatAsMFile, solver_name, ode, tspan, y0, options, varargin);

subplot 211
plot(time,Y(:,11));
xlabel('time')
ylabel('phase')


subplot 212
plot(time,Y(:,12));
xlabel('time')
ylabel('Amplitude')

[Ankit]

clc
ti = 0;
tf = 1E-3;
tspan=[ti tf];
P = 1.27;
a = 0.1;
tc = 230E-6;
tp = 5.4E-9;
o = rand(1,5)*100E3;
k = 1E-3;
k1 = k;
k2 = k;
k3 = k;
k4 = k;
k5 = k;


f = @(t,y) [
    (P - y(1).*((abs(y(6)))^2 +1))./tc;
    (P - y(2).*((abs(y(7)))^2 +1))./tc;
    (P - y(3).*((abs(y(8)))^2 +1))./tc;
    (P - y(4).*((abs(y(9)))^2 +1))./tc;
    (P - y(5).*((abs(y(10)))^2 +1))./tc;
    (y(1)-a).*((y(6))./tp) + (k1./tp).*(y(7)).*cos(y(11)) + (k5./tp).*(y(10))*cos(y(15));
    (y(2)-a).*((y(7))./tp) + (k2./tp).*(y(8)).*cos(y(12)) + (k1./tp).*(y(6))*cos(y(11));
    (y(3)-a).*((y(8))./tp) + (k3./tp).*(y(9)).*cos(y(13)) + (k2./tp).*(y(7))*cos(y(12));
    (y(4)-a).*((y(9))./tp) + (k4./tp).*(y(10)).*cos(y(14)) + (k3./tp).*(y(8))*cos(y(13));
    (y(5)-a).*((y(10))./tp) + (k5./tp).*(y(9)).*cos(y(14)) + (k4./tp).* (y(6))*cos(y(15));
    o(1,1) - (k1./tp).*(y(6)/y(7)).*(sin(y(11))) - (k1./tp).*(y(10)/y(6)).*(sin(y(11))) + (k2./tp).*(y(8)./y(7))*sin(y(12)) + (k5./tp).*(y(10)/y(6)).*sin(y(15));
    o(1,2) - (k2./tp).*(y(7)/y(8)).*(sin(y(12))) - (k2./tp).*(y(8)/y(7)).*(sin(y(12))) + (k3./tp).*(y(9)./y(8))*sin(y(13)) + (k1./tp).*(y(6)/y(7)).*sin(y(11));
    o(1,3) - (k3./tp).*(y(8)/y(9)).*(sin(y(13))) - (k3./tp).*(y(9)/y(8)).*(sin(y(13))) + (k4./tp).*(y(10)./y(9))*sin(y(14)) + (k2./tp).*(y(7)/y(8)).*sin(y(12));
    o(1,4) - (k4./tp).*(y(9)/y(10)).*(sin(y(14))) - (k4./tp).*(y(10)/y(9)).*(sin(y(14))) + (k5./tp).*(y(6)./y(10))*sin(y(15)) + (k3./tp).*(y(8)/y(9)).*sin(y(13));
    o(1,5) - (k5./tp).*(y(10)/y(6)).*(sin(y(15))) - (k5./tp).*(y(6)/y(10)).*(sin(y(15))) + (k1./tp).*(y(7)./y(6))*sin(y(11)) + (k4./tp).*(y(9)/y(10)).*sin(y(14));];
   
    
[time,Y] = ode45(f,tspan./tp,[0; 0; 0; 0; 0; 1; 1; 1; 1; 1; 0.01; 0.01; 0.01; 0.01; 0.01],o)

subplot 211
plot(time,Y(:,11));
xlabel('time')
ylabel('phase')


subplot 212
plot(time,Y(:,12));
xlabel('time')
ylabel('Amplitude')

Unfortunately your code is taking too much time to run.. I didnt check in details

But your Problem related to dimension is removed

Answer 1

[Sam Chak]

Hi @SAHIL SAHOO

I guess that is an error in your ode argument, things that are inside the brackets of ode45().

I believe 'o' stands for options in your case. Try something like this:

o = odeset('RelTol', 1e-2, 'AbsTol', 1e-5);
[time,Y] = ode45(f, tspan./tp, [0; 0; 0; 0; 0; 1; 1; 1; 1; 1; 0.01; 0.01; 0.01; 0.01; 0.01], o);

Also check out this:

https://www.mathworks.com/help/matlab/math/summary-of-ode-options.html