Converting LSF to Frequency Domain

I have a Line Spread Function (LSF), which is plotted against pixel positions in (um). This is a sample of that data:

position = [-1.780405 -1.186936 -0.593468 0 0.593468 1.186936 1.780405 2.373873]; %x-axis position(um)
LSF = [48.172258 48.866131 46.863226 49.217079 46.385073 40.899024 39.912261 37.784698 ]; %y-axis signal LSF
plot(x,y)
xlabel('Pixel Position (um)')
ylabel('LSF')

I have 251 positions and 251 LSF, but here I am showing 8 elements of each only.

I want to convert LSF signal to frequency domain and plot it against frequency (ω) instead of pixel position. Can someone help me out with this? Any hints are appreciated.