overplotting 6 graphs by changing into 3 graphs

 Two M-files one contains differential equations and another one to run and plot the graphs. since i am using ode solver, it has two files to run.

THERE ARE 4 MATLAB CODES WITH 4 SEPARATE MATLAB M-FLIES BUT 2 M-FILES TO PRODUCE 3 PLOTS AND ANOTHER 2 M-FILES TO PRODUCE ANOTHER 3 GRAPHS. BUT I WANT TO OVERPLOTS THESE 6 PLOTS INTO 3 PLOTS ONLY.

HERE ARE THE FIRST two M-files, ONE contains differential equations and another one CONTAINS plotting the graphs. since i am using ode solver, it has two files.

% Creating recent original 3 ode without scaling any parameters and c.

        function xprime= ns(t,x)

        I=1200; % light intensity

        %values of parameters
          k_f= 6.7*10.^7;
          k_d= 6.03*10.^8; 
          k_n=2.92*10.^9; 
          k_p=4.94*10.^9;
          alpha =1.14437*10.^-3;

          %Unknown parameters
          lambda_b= 0.0087;
          lambda_r =835; 
          gamma =2.74; 

          %Pool Values
          P_C= 3 * 10.^(11);
          P_Q= 2.87 * 10.^(10); 

       % initial conditions
        c=x(1);
        s=x(2);
        q=x(3);

        %Non-linear differential equations.
        % dc/dt= alpha*I + c(- k_f - k_d - k_n * s - k_p*(1-q))
        % ds/dt = lambda_b * c* P_C *(1-s)- lambda_r *(1-q)*s
        % dq/dt = (1-q)* k_p * c *(P_C / P_Q)- gamma * q

       xprime = zeros(3,1);    % a column vector

      xprime(1)= alpha*I + c*(- k_f - k_d - k_n * s - k_p*(1-q));
      xprime(2)= lambda_b *(1-s)*c* P_C  - lambda_r *(1-q)*s;
      xprime(3)=(1-q)*k_p* c*(P_C / P_Q)- gamma * q;

   % TO RUN the recent original odes with t= 0.2 *10^-9

        format bank
        close all; 
        clear all; 
        clc; 
      epison= 10.^-9;
        %time interval
        ti=0; 
        tf=0.2*epison; 
        tspan=[ti tf]; 

        x0=[0.25 0.02 0.98]; %initial conditions

        %time interval of [0 2] with initial condition vector [0.25 0.02 0.98] at time 0.
        options= odeset('RelTol',1e-9, 'AbsTol',[1e-9 1e-9 1e-9]);
        [t,x]= ode23s(@ns,tspan,x0,options); 
      dt = t(2:end)-t(1:end-1);  % number of time step size it is using

      %Plotting the graphs:
      plot(t(2:end), t(2:end)-t(1:end-1));   % plotting the time step size.
       title('Time steps for 3 recent original odes (c,s,q), time =0.2*10^-9 ');
      ylabel('t'), xlabel('t_n'); 

        figure 
        subplot(3,1,1), plot(t,x(:,1),'r'),grid on; 
        title('3 recent original odes, time =0.2*10^-9 '),ylabel('c'); 

        subplot(3,1,2), plot(t,x(:,2),'b'),grid on; 
        ylabel('s'); 

        subplot(3,1,3), plot(t,x(:,3),'g'),grid on; 
        ylabel('q');xlabel('Time')

Another separate two M-files which contains differential equations and another contains plotting the graphs. since i am using ode solver, it has two files.

% 3 Asymptotic expansion t=0.2*10^-9 which gives tau =0.2

        function xpr= no(t,x)
          epison= 10.^-9; 
        %values of parameters
          k_f= 6.7*10.^7;
          k_d= 6.03*10.^8; 
          k_n=2.92*10.^9; 
          k_p=4.94*10.^9;

          %Unknown parameters
          lambda_b= 0.0087;

          % scale parameters
          K_F= k_f *   epison;
          K_D= k_d *   epison; 
          K_N= k_n *   epison; 
          K_P= k_p *   epison;
          LAMBDA_B= lambda_b*  epison;

          %Pool Values
          P_C= 3 * 10.^(11);
          P_Q= 2.87 * 10.^(10); 

       % initial conditions
        c_0=x(1);
        s_0=x(2);
        q_0=x(3);

        %Non-linear differential equations.
        % dc_0/dtau=  c_0*(- K_F - K_D - K_N * s_0 - K_P*(1-q_0))
        % ds_0/dtau = Lambda_B * c* P_C *(1-s_0)
        % dq_0/dtau = (1-q_0)* K_P * c_0 *(P_C / P_Q)

        % dc_0/dt=  c_0*(- K_F - K_D - K_N * s_0 - K_P*(1-q_0))
        % ds_0/dt = Lambda_B * c_0* P_C *(1-s_0)
        % dq_0/dt = (1-q_0)* K_P * c_0 *(P_C / P_Q)

      xpr= zeros(3,1);

      xpr(1)=c_0*(- K_F - K_D - K_N * s_0 - K_P*(1-q_0));
      xpr(2)= LAMBDA_B * c_0*P_C *(1-s_0);
      xpr(3)= (K_P * c_0*P_C*(1-q_0)) / P_Q;

      % TO RUN 3 asymptotic expansion for c_0,s_0 and q_0

        format bank
        close all; 
        clear all; 
        clc; 
      epison= 10.^-9;

        %time interval
        ti=0; 
        tf=0.2*epison; 
        tspan=[ti tf]; 

        x0=[0.25 0.02 0.98]; %initial conditions

        %time interval of [0 2] with initial condition vector [0.25 0.02 0.98] at time 0.
        options= odeset('RelTol',1e-9, 'AbsTol',[1e-9 1e-9 1e-9]);
        [t,x]= ode23s(@no,tspan,x0,options); 
      dt = t(2:end)-t(1:end-1); % number of time step size it is using

      %Plotting the graphs:
        plot(t(2:end), t(2:end)-t(1:end-1));   % plotting the time step size.
         title('Time steps for 3 asymptotic expansions (c_0,s_0, q_0) at tau=0.2');
        ylabel('t'), xlabel('t_n'); 

        figure 
        subplot(3,1,1), plot(t,x(:,1),'r'),grid on; 
        title('3 asymptotic expansion when t=0.2*epsion, tau= t/epison, so tau=0.2'),ylabel('c_0'); 

        subplot(3,1,2), plot(t,x(:,2),'b'),grid on; 
        ylabel('s_0'); 

        subplot(3,1,3), plot(t,x(:,3),'g'),grid on; 
        ylabel('q_0');xlabel('Time')

There are 6 plots from these two separate m-files which contains 3 each graphs and there are different. Now i want to overplot 3 plots by combining 6 plots together into 3 plots. I mean one overplot containing c and c_0, another for s and s_0 and last one for q and q_0 and 3 in total. Time intervals of these 3 plots can be between 0 to 0.2*10-9. please help me. i will be very much grateful and thankful for your help.

Answer 1

[Aurele Turnes]

You can plot multiple lines into one subplot by using the hold on command and removing the call to figure. In your first MATLAB file, write:

% figure  % remove this line
subplot(3,1,1)
plot(t,x(:,1),'r');
grid on;
hold on;  % add this line
title('3 recent original odes, time =0.2*10^-9 ');
ylabel('c'); 
subplot(3,1,2)
plot(t,x(:,2),'b');
grid on;
hold on; % add this line
ylabel('s'); 
subplot(3,1,3)
plot(t,x(:,3),'g');
grid on;
hold on; % add this line
ylabel('q');
xlabel('Time');

and in your second MATLAB file:

% figure  % remove this line
subplot(3,1,1)
plot(t,x(:,1),'r');
grid on;
hold on; % add this line
title('3 asymptotic expansion when t=0.2*epsion, tau= t/epison, so tau=0.2');
ylabel('c_0'); 
subplot(3,1,2) 
plot(t,x(:,2),'b');
grid on;
hold on; % add this line
ylabel('s_0'); 
subplot(3,1,3)
plot(t,x(:,3),'g');
grid on;
hold on; % add this line
ylabel('q_0');
xlabel('Time');

By doing this, it should not matter which MATLAB file you execute first. However, note that only the title, x-label and y-label for the second MATLAB file you execute will show. I would suggest using the legend function instead. You may also want to use different colors, markers or linewidth for your second MATLAB file to distinguish the two curves. For instance:

subplot(3,1,1), plot(t,x(:,1),'-*r','Linewidth',2, 'DisplayName', 'c_0');
legend('show')

Refer to the documentation pages for legend and line properties to learn more about your options.