How to find the difference between two graphs?

I have a graph shown in the figure below and now i have to find difference between two graphs, red line is drawn from some A= 59x2 matrix(taken from matlab Simulink) and blue line drawn from B= 149x2 matrix both drawn for same parameters and i don't have any idea how to find the difference between both the lines. So if anyone has any idea please help me with that.

code used is

figure();plot(simout.A.Time,simout.A.Data);
hold on;
plot(B(:,1),B(:,2));

Thanks in advance Agastya

Answer 1

[the cyclist]

The curves are pretty smooth, so you could use the interp1 command to create y values at common x points for the two curves, and then take the differences of those y values.

[Agastya]

Hi, Can you just tell me the code with interp1 for my case?

[the cyclist]

This should give the y values for your two series, at x values of 0, 0.01, 0.02, ... 1.00

xq = 0 : 0.01 : 1;

yqA = interp1(simout.A.Time,simout.A.Data,xq);
yqB = interp1(B(:,1),B(:,2),xq);

[Agastya]

Hi, Thank you very much

[Saraswatula Sai Pavan Sastry Sastry SOME]

Hello the cyclist, what if the x values aren't common?Then how to find the difference?

Answer 2

[Ahmet Cecen]

One way is to interpolate the 59x2 matrix to be 149x2. Check spectral interpolation using Fourier transforms. You might even be able to get away with imresize in your case.

[Agastya]

Hi, Can you just tell me the code with interp1 for my case?