circularly shifts the elements of the matrix z so that
the first row corresponds to the center row of that result,
and the first column of z corresponds to the center column
of the result.
If z is a vector and the result of a
one dimensional discrete transform
or if it is a matrix and the result of a
two dimension discrete transform,
fftshift shifts the zero frequency to the center of the grid.
If you enter
z = 1 :: 4
O-Matrix will reply
In O-Matrix mode,
the routine dft
performs the discrete transform
and the routine fft
does this shifting automatically.
is the discrete transform.