Recovering precise points on a graph

Hello everyone,

I have several matlab graphs representing FFT of different signals, I try to recover only some frequencies and amplitudes

in order to arrange them in a table. with the uitable function.

I thought that by using the following line of code :

dat = {(fft_3(10000)), fft_3(30000) ,fft_3(90000), fft_3(200000), fft_3(400000)};

This would work. but the value of the amplitudes, has strictly nothing to do with those I can find in my graph

Answer 1

[Sulaymon Eshkabilov]

You may try using graphical input with ginput(), e.g:

[x, y] = ginput(5);  % Five freq. values, viz mag and f values will be picked up.