ifftshift function

Inverse zero-frequency shift

Rearranges a zero-frequency-shifted Fourier transform back to the original.

ifftshift(x, MARGIN = 2)

Arguments

• x: input data, specified as a vector or matrix.
• MARGIN: dimension to operate along, 1 = row, 2 = columns (default). Specifying MARGIN = c(1, 2) centers along both rows and columns. Ignored when x is a vector.

Returns

back-transformed vector or matrix.

Details

Undo the action of the fftshift function. For even length x, fftshift is its own inverse, but not for odd length input.

Examples

Xeven <- 1:6
res <- fftshift(fftshift(Xeven))

Xodd <- 1:7
res <- fftshift(fftshift(Xodd))
res <- ifftshift(fftshift(Xodd))

See Also

fftshift

Author(s)

Vincent Cautaerts, vincent@comf5.comm.eng.osaka-u.ac.jp ,

adapted by John W. Eaton.

Conversion to R by Geert van Boxtel, G.J.M.vanBoxtel@gmail.com .