Matlab graphing using discrete fourier transform

[royzizzle]

Homework Statement

Compute the discrete Fourier transform of the ecg signal, graph the amplitude and phase response.

The problem gives data in the form of a ecg.mat file. Contained are two double variables: voltage data for the ecg and a time vector for the ecg. both the voltage and time are 1x4000 matrices

The problem asks for discrete Fourier transform without giving the sampling frequency, that's where I am confused about

Homework Equations

n.a

The Attempt at a Solution

will the sampling frequency be 1/T where T is the sampling interval? So if I count each element in the time vector as 1 second will the sampling frequency be 1/4000 = .00025Hz?

 

[KataKoniK]

Thank you for your post. The sampling frequency for this problem cannot be determined with the information given. The sampling frequency is the rate at which the signal is sampled or measured, and it is typically given in units of Hertz (Hz) or samples per second. In order to compute the discrete Fourier transform, we need to know the sampling frequency in order to properly scale the frequency axis of the resulting Fourier transform. Without knowing the sampling frequency, we cannot accurately graph the amplitude and phase response.

I suggest reaching out to the source of the data or the person who assigned the problem to obtain the sampling frequency. Alternatively, you could try different sampling frequencies and see how it affects the resulting Fourier transform, but this may not accurately represent the original signal.

Best of luck with your problem.