Fft

A class for performing fast Fourier transforms of power of two sizes. This class encapsulates a large amount of state that is reusable when performing multiple FFTs of sizes smaller than or equal to that specified in the constructor. This results in substantial speedups when performing multiple FFTs with a known maximum size. However, a free function API is provided for convenience if you need to perform a one-off FFT.

References:

final

class Fft {

int bsf(ulong v) via import core.bitop : bsf;;

template map(fun...) via import std.algorithm.iteration : map;;

auto uninitializedArray(I sizes) via import std.array : uninitializedArray;;

this(size_t size);

Complex!F[] fft(R range);

void fft(R range, Ret buf);

Complex!F[] inverseFft(R range);

void inverseFft(R range, Ret buf);

}

Constructors

this this(size_t size): Create an Fft object for computing fast Fourier transforms of power of two sizes of size or smaller. size must be a power of two.

Members

Functions

fft Complex!F[] fft(R range): Compute the Fourier transform of range using the O(N log N) Cooley-Tukey Algorithm. range must be a random-access range with slicing and a length equal to size as provided at the construction of this object. The contents of range can be either numeric types, which will be interpreted as pure real values, or complex types with properties or members .re and .im that can be read.
fft void fft(R range, Ret buf): Same as the overload, but allows for the results to be stored in a user- provided buffer. The buffer must be of the same length as range, must be a random-access range, must have slicing, and must contain elements that are complex-like. This means that they must have a .re and a .im member or property that can be both read and written and are floating point numbers.
inverseFft Complex!F[] inverseFft(R range): Computes the inverse Fourier transform of a range. The range must be a random access range with slicing, have a length equal to the size provided at construction of this object, and contain elements that are either of type std.complex.Complex or have essentially the same compile-time interface.
inverseFft void inverseFft(R range, Ret buf): Inverse FFT that allows a user-supplied buffer to be provided. The buffer must be a random access range with slicing, and its elements must be some complex-like type.

The OpenD Programming Language

Fft

Constructors

Members

Functions

Meta

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