Comparing two plots which are functions of time

I have two signals which are functions of time t, which when plotted gives the desired graphs.

I need to display that these plots are equal and hence, linear. How do I do this? I tried comparing the function handles I used, but they are not accurate.

Data I have used :-

t = -10:0.1:10

x1(t) = 2sin(2*pi*3t)

x2(t) = 3sin(2*pi*2t)

y(x) = t.*x

Answer 1

[VBBV]

 %if true
%if true
t = -10:0.1:10;
x1 = 2*sin(2*pi*3*t);
x2 = 3*sin(2*pi*2*t);
y11 = t.*(x1+x2);
plot(t,y11,'b'); figure; 
y1 = t.*x1+t.*x2;
plot(t,y1,'r')

[Krishnaraja Sagar]

This code plots the two graphs, but how do I check whether the graphs on the two plots are same or not?

The aim of this MATLAB app is to check whether a system is linear or not. If the plots are identical, I need to display 'Linear', otherwise display 'Non-Linear'. The plots are coming out accurately, but I just cannot do a comparison between the two graphs so that I can display text accordingly. I hope my question is clear.

Thank you.

[VBBV]

%if true
if abs(y11-y1) == 0
disp('linear');
else 
disp('Nonlinear')
end

[Krishnaraja Sagar]

This is the result I got after using the above code(Just changed to subplot for better visualization). Still doesn't work..

[VBBV]

What doesn't work ?

[Krishnaraja Sagar]

The required result text is 'linear', since both the graphs are identical

[VBBV]

if abs(round(y11)-round(y1)) == 0
disp('linear');
else 
disp('Nonlinear')
end

Use round function as above as the differences between two outputs are very very small.

You would get it linear as output

[Krishnaraja Sagar]

Thank you so much...!!

Have been stuck on this simple problem for a long time... :)

[VBBV]

welcome. Please accept the answer