How to transform y1(t) to Y1(S) in frequency domain.

By using of Fast Fourier Transform (FFT) in MATLAB,I want to transform y1(t) to Y1(S) in frequency domain.

How can I do that?

I have the y1(t) in workspace as .mat data.

I've attached a .JPG file.

Thank you so much

Answer 1

[Image Analyst]

Did you try

Y1 = fft(y1);

???

[vahid torabi]

I want to plot Y1 ; how about the horizontal axis?