HOW TO OVERWRITTE PLOTS IN A FOR LOOP

I want to overwritte plots coming from other files in a FOR loopm, in order so that each plot generated is held and the next one in the loop is also in drawn in the plot. I also want that the legend changes for every loop. I write the code:

% calculates the acceleration of a vehicle using the two codes:
vehicle_2021_v_p
electric_drive_2021

close all
%wm: motor speed [rad/s]
wm=n*2*pi/60;


for i= 1: length (rt)
    %v_m: vehicle speed using speed discretization of motor [m/s]
    v_m=wm/rt(i)*rw;

    %f_m: tractive effort(i) using the speed discretization of the motor [N]
    f_m=t*rt(i)/rw;

    %ft: tractive effort(i) using vehicle speed discretization step dv [N]
    ft=interp1(v_m,f_m,v);
        
    	hold on
        figure 
        subplot(2,1,1)
        plot(vkph,ft, vkph, fl, 'linewidth',2)
        grid
        xlabel ('vehicle speed [km/h]')
        ylabel ('[N]')
        title ('FORCE')
        legend ('TRACTIVE EFFORT','LOAD')
        
        subplot(2,1,2)
        plot(vkph,ft.*v/1000, vkph, fl.*v/1000, 'linewidth',2)
        grid
        xlabel ('vehicle speed [km/h]')
        ylabel ('[kW]')
        title ('POWER')
        legend ('TRACTIVE EFFORT','LOAD')     
    %tl_v: load torque using vehicle speed sampling [Nm]
    tl_v=fl*rw/rt(i);

    %n_v: motor speed using vehicle speed sampling [rpm]
    n_v=v/rw*rt(i)*60/2/pi;

    %tl: load torque using motor speed sampling [Nm]
    tl=interp1(n_v,tl_v,n);
    
        figure 
        subplot(2,1,1)
        plot(n(:,i),t(:,i), n(:,i), tl(:,i), 'linewidth',2)
        grid
        xlabel ('motor speed [rpm]')
        ylabel ('[Nm]')
        title ('TORQUE')
        legend ('MOTOR','LOAD')

        subplot(2,1,2)
        plot(n,p/1000, n, tl.*n*2*pi/60/1000, 'linewidth',2)
        grid
        xlabel ('motor speed [rpm]')
        ylabel ('[kW]')
        title ('POWER')
        legend ('MOTOR','LOAD')


    %% ACCELERATION CALCULATION %%%
    %facc: acceleration force  [N]
    facc=ft-fl;

    %i_pos_acc: indexes of positive acceleration 
    i_pos_acc=find(facc>0);

    %i_max_speed: index of maximum speed
    i_max_speed=length(i_pos_acc);

    %v_max: top speed [km/h]
    v_max =v(i_max_speed)*3.6

    %acc: acceleration [m/s^2]
    acc=facc(i_pos_acc)/mg;

    %max_acc: maximum accelration [m/s^2]
    max_acc=max(acc);

    %g_max: maximum accelration [g]
    g_max=max_acc/9.81;

    %acc=dv/dt

    %dt: vector of delta time for each dv [s]
    dt=dv./acc;

    %time: acceleration time [s]
    time=cumsum(dt);


    %d_dst: delta distance [m]
    d_dst=v(i_pos_acc).*dt;

    %distance: total distance [m]
    distance=cumsum(d_dst);

        figure(i)
        subplot(3,1,1)
        plot(time, acc, 'linewidth',2)
        grid
        xlim([0 200])
        title('ACCELERATION')
        xlabel ('time [s]')
        ylabel ('[m/s^2]')

        subplot(3,1, 2)
        plot(time, v(i_pos_acc)*3.6, 'linewidth',2)
        grid
        xlim([0 200])
        title('SPEED')
        xlabel ('time [s]')
        ylabel ('[km/h]')

        subplot(3,1, 3)
        plot(time, distance, 'linewidth',2)
        grid
        xlim([0 200])
        title('DISTANCE')
        xlabel ('time [s]')
        ylabel ('[m]')
end

Answer 1

[Rishik Ramena]

Since you want to update the plot keeping the old data intact, add a pause after the plot and 'hold on' after the first plot. a sample code is provided for your reference.

figure; title('Plot loops');
A = rand(1,10);
B = rand(1,10);
N = length(A);
for idx=1:N
      plot(A(1:idx),B(1:idx), '*-');
      legend(['test' int2str(idx)]);
      hold on
      pause(2)
end
hold off