ILMathfft Method (InArrayDouble, NullableUInt32)

public static RetArray<complex> fft(
	InArray<double> A,
	Nullable<uint> dim = null
)

Public Shared Function fft ( 
	A As InArray(Of Double),
	Optional dim As Nullable(Of UInteger) = Nothing
) As RetArray(Of complex)

Dim A As InArray(Of Double)
Dim dim As Nullable(Of UInteger)
Dim returnValue As RetArray(Of complex)

returnValue = ILMath.fft(A, dim)

Parameters

A

Type: ILNumericsInArrayDouble
Real input data array.

dim (Optional)

Type: SystemNullableUInt32
[Optional] The working dimension. Default: (null) first non-singleton dimension of A or dimension #0.

Return Value

The output array returned will be complex hermitian. I.e. the real part being even and the imaginary part being odd symmetrical.

The forward fourier transform and the inverse fourier transform of a given data array A are mathematically equivalent. It's only a scaling factor which is needed to make sure, A equals ifft(fft(A)). That scaling is introduced in the inverse transform.

The transformation is computed by use of the native library which currently is set up for your processor and OS version. The underlying library is automatically selected by ILNumerics at startup and accessed via the static member ILMath.FFT. See the online documentation for more details in how to tune/configure and select dedicated native libraries. Currently supported libraries are: Intel MKL (included), AMD ACML and FFTW3 (prepared, optional modules, not included due to licensing conflicts).

[ILNumerics Computing Engine]

Reference