fft()

Performs the discrete Fourier transform

Syntax
y = fft(x, length)

Arguments

Name	Description	Range	Type	Required
x	data to be transformed	(-∞, ∞)	integer, real, complex	yes
length	length of the transform	[1, ∞)	integer	yes

Examples

fft([1, 1, 1, 1])
returns [4+0i, 0+0i]
fft([1, 0, 0, 0]
returns [1+0i, 1+0i]
fft(1, 4)
returns [1+0i, 1+0i]

Defined in

Built in

See Also

fs(), ts()

Notes/Equations

The fft() function uses a high-speed radix-2 fast Fourier transform when the length of x is a power of two. fft(x, n) performs an n-point discrete Fourier transform, truncating x if length(x) > n and padding x with zeros if length(x) < n.
fft() uses a real transform if x is real and a complex transform if x is complex. If the length of x is not a power of two, then a mixed radix algorithm based on the prime factors of the length of x is used.
The fft() function is designed to work with uniformly spaced waveforms. If a non-uniform waveform is input, then the output spectrum will be incorrect. For non-uniformly spaced data, use the fs() function.