Interplay of fft, ifft, fftshift, and ifftshift in MATLAB

This file clarifies assumptions about the position of origin in computation of DFT

This script was used to publish a post by the same title:
http://www.mshalin.com/blog/?p=467, where I tried to clarify the assumptions made in computation of DFT (by FFT algorithm). These assumptions have important consequences. This script takes the example of obtaining real and even Fourier/inverse Fourier transform from a real and even function.