Deleting some parts of a figure

greeting guys! I got a code which result is a figure of output y with respect to t (time). I wanted to keep some part of this figure for example from time 5 till 9 and delete other parts. I wanted to know how to do that.

my code is as follows:

clc;
clear;
close all;
%% Initialization
T0=0 ;
Tf=20 ;
Ts=0.1 ;
t=T0:Ts:Tf ;
system=tf([1 1],[1 1 2]); % system=(s+1)/(s^2+s+2)
system_dis=c2d(system,Ts) ;
system_dis_ss=ss(system_dis) ;
Am=system_dis_ss.a;
Bm=system_dis_ss.b;
Cm=system_dis_ss.c;
n=size(Am,1); % Number of state variables
Om=zeros(1,n);
A=[Am,Om';Cm*Am,1];
B=[Bm ;Cm*Bm];
C=[Om 1];
p=10; % Prediction horizon
m=5; % Control horizon
Q=1;
R=1;
F=zeros(p,n+1);
for i=1:p
    F(i,:)=C*A^i;
end
PHI=zeros(p,m);
for i=1:p
    for j=1:i
        PHI(i,j)=C*A^(i-j)*B;
    end
end
PHI=PHI(:,1:m);
%% Main Loop
Nt=numel(t);
%W=ones(Nt,1); % Reference signal
W=[ones(floor(Nt/4),1);2*ones(floor(Nt/4),1);-ones(floor(Nt/4),1);zeros(floor(Nt/4+1),1)];
y=zeros(Nt,1);
du=zeros(Nt,1);
x=zeros(n+1,Nt); % (System state)+integral ===> n+1
Fval=zeros(Nt,1);
for i=1:Nt-1
    FreeResponse=F*x(:,i);
    dU=(PHI'*Q*PHI+R)\(PHI'*Q*(W(i)-FreeResponse))
    du(i)=dU(1); % Receding horizon
    x(:,i+1)=A*x(:,i)+B*du(i); % State variable update 
    y(i+1)=C*x(:,i+1); % Output update
end
%% Plot result
figure(1)
plot(t,y,'linewidth',2)

[Ankit]

you can limit your x-axes and y-axes using xlim and ylim

xlim: https://de.mathworks.com/help/matlab/ref/xlim.html

plot(t,y,'linewidth',2)
xlim([5 9]);

[Adam]

If you want to do this permanently why not just only plot the bits you want to keep in the first place?! You can use logical indexing into your t vector to give you a logical vector to apply to the y vector for only the times you want.

[Alex Mcaulley]

plot(t(5:9),y(5:9),'linewidth',2) %??

[Ali Esmaeilpour]

plot(t(5:9),y(5:9),'linewidth',2)

nope that's not right because I dont want to change "y". I just want to keep those parts from time 5 till 9.

[Ali Esmaeilpour]

If you want to do this permanently why not just only plot the bits you want to keep in the first place?!  You can use logical indexing into your t vector to give you a logical vector to apply to the y vector for only the times you want.

How to do that Adam???

[Sebastian Körner]

plot(t(5:9),y(5:9),'linewidth',2) %??

with that you dont change "y" at all, you just dont plot all of it

[Ali Esmaeilpour]

t is 1*201 and y is 201*1 so we can't simply have t(5:9) can we???

Answer 1

[Steven Lord]

timesInRange = (5 <= t) & (t <= 9);
plot(t(timesInRange), y(timesInRange))

Depending which of the endpoints you want to keep, you may need to use < instead of <= in one or both conditions.

For more information about how this works, see this documentation page and/or some of the blog posts that discuss "logical indexing".