How to plot fft in MATLAB from the given x and y values in text format using rectangular windowing?

Hello,

I am new in MATLAB. I am having a data base which contains 2048 , x values correspond to y values in txt format. for example

x y

1 89

2 98

. .

. .

. .

2048 96

I just want to ask a question how to plot fft of these values using rectangular windowing? Please suggest the MATLAB code of this. I will be highly obliged of you because it is very important for my project.

[Dishant Arora]

Rectangular window is like no window at all. So, you can plot fft using:

stem(abs(fft(y)))

[Sanjay Saxena]

Thanks Dishant for your valuable answer. Actually when i am plotting fft as you said, than i am not be able to see peaks of fft. If i am plotting fft with another software(SW 340) than i can exactly locate peaks. Please short out this problem.

[Dishant Arora]

Are you getting multiple peaks?? It might happen due un-coherent sampling. You must know what are spectral leakage and scalloping losses.