|MATLAB Function Reference|
Multidimensional inverse discrete Fourier transform
Y = ifftn(X)
returns the n-dimensional inverse discrete Fourier transform (DFT) of
X, computed with a multidimensional fast Fourier transform (FFT) algorithm. The result
Y is the same size as
X to see whether it is conjugate symmetric. If so, the computation is faster and the output is real. An
X is conjugate symmetric if
for each element of
Y = ifftn(X,siz)
X with zeros, or truncates
X, to create a multidimensional array of size
siz before performing the inverse transform. The size of the result
y = ifftn(..., 'symmetric') causes
ifftn to treat
X as conjugate symmetric. This option is useful when
X is not exactly conjugate symmetric, merely because of round-off error.
y = ifftn(..., 'nonsymmetric') is the same as calling
ifftn(...) without the argument
X within roundoff error.
ifftn(X) is equivalent to
This computes in-place the one-dimensional inverse DFT along each dimension of
The execution time for i
fftn depends on the length of the transform. It is fastest for powers of two. It is almost as fast for lengths that have only small prime factors. It is typically several times slower for lengths that are prime or which have large prime factors.
You might be able to increase the speed of |
Data Type Support
ifftn supports inputs of data types
single. If you call
ifftn with the syntax
y = ifftn(X, ...), the output
y has the same data type as the input
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