gsignal (version 0.3-1)

ifftshift: Inverse zero-frequency shift

Description

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

Usage

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.

Value

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.

See Also

fftshift

Examples

# NOT RUN {
Xeven <- 1:6
res <- fftshift(fftshift(Xeven))

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

# }