discrete Fourier transform maximum value

Hi, guys, I have question bout DFT problems I'm trying to find the maximum absolute value of DFT. The original signal is sin wave with 2KHz. Sampling frequencies are 10KHz. N=100 samples of this signal are transformed using the DFT, yielding 100 samples in frequency domain: X0, X1,…,XN-1. And, wondering which samples have maximum absolute values?

Answer 1

[Star Strider]

Use the Signal Processing Toolbox findpeaks function. It will return the maximum value and the associated frequency.

Otherwise, use the max function with 2 outputs. The second output is the index of the maximum value. Use that with your frequency vector to find the maximum value.

[Soomin Yang]

Really thanks for your help :) Is there any other way to find without using MATLAB? I mean just calculate or estimate by hands.

[Star Strider]

My pleasure.

If you are calculating it by hand, plot it and then just look at the plot to see where the maximum is!