Fitting data to a new set of frequency

I have two sets of data across two difference frequency points. I need to operate on these two data but since they have different length I'm unable to perform my operations. I'd like to define a unified set of frequency points and fit each of these two set of data to these new frequency points. Can someone please help me with the easiest method/function to do this?

For example, Data1 has frequency points at 1:0.33:34 and Data2 has frequency points 2:0.5:21 and I want to fit both data to frequency points 2:1:20. Thank you.

Answer 1

[Voss]

You can use interp1. Example follows:

% some made-up data defined on those frequency vectors
f1 = 1:0.33:34;
f2 = 2:0.5:21;
x1 = 0.25*sind(f1*2);
x2 = 0.2*cosd(f2*4);

% specified common frequency vector
f = 2:1:20;

% plot the original data
figure
plot(f1,x1,'-b',f2,x2,'-r')

% interpolate to common f
x1i = interp1(f1,x1,f);
x2i = interp1(f2,x2,f);

% plot interpolated values
hold on
plot(f,x1i,'bo',f,x2i,'ro')

% make a legend
legend('x1','x2','x1i','x2i')

[Mohammad Khorshidian]

This is exactly what I needed. Thank you so much.

[Voss]

You're welcome!