► |  | Math Library

1 | Constants and Elementary Functions
2 | Flonums
3 | Special Functions
4 | Number Theory
5 | Arbitrary-Precision Floating-Point Numbers (Bigfloats)
6 | Arrays
7 | Matrices and Linear Algebra
8 | Statistics Functions
9 | Probability Distributions
10 | Stuff That Doesn’t Belong Anywhere Else

▼ | 6 | Arrays

6.1 | Quick Start
6.2 | Definitions
6.3 | Broadcasting
6.4 | Slicing
6.5 | Nonstrict Arrays
6.6 | Types, Predicates and Accessors
6.7 | Construction
6.8 | Conversion
6.9 | Comprehensions and Sequences
6.10 | Pointwise Operations
6.11 | Indexing and Slicing
6.12 | Transformations
6.13 | Folds, Reductions and Expansions
6.14 | Other Array Operations
6.15 | Subtypes
6.16 | Strictness

► | 6.14 | Other Array Operations

6.14.1 | Fast Fourier Transform

On this page:

6.14.1`` Fast Fourier Transform
array-axis-fft
array-axis-inverse-fft
array-fft
array-inverse-fft

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#### 6.14`` Other Array Operations

##### 6.14.1`` Fast Fourier Transform

> > > Wikipedia: Discrete Fourier Transform

> > procedure

> > (array-axis-fft arr k) → (Array Float-Complex)

> arr : (Array Number)
> k : Integer

Performs a discrete Fourier transform on axis k of arr. The length of k must be an integer power of two. (See power-of-two?.) The scaling convention is determined by the parameter dft-convention, which defaults to the convention used in signal processing.

The transform is done in parallel using max-math-threads threads.

> > procedure

> > (array-axis-inverse-fft arr k) → (Array Float-Complex)

> arr : (Array Number)
> k : Integer

The inverse of array-axis-fft, performed by parameterizing the forward transform on (dft-inverse-convention).

> > procedure

> > (array-fft arr) → FCArray

> arr : (Array Number)

Performs a discrete Fourier transform on each axis of arr using array-axis-fft.

> > procedure

> > (array-inverse-fft arr) → FCArray

> arr : (Array Number)

The inverse of array-fft, performed by parameterizing the forward transform on (dft-inverse-convention).
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