Matrix Gallery

A collection of functions to generate various types of feedback matrices. More...

Functions
std::vector< float >	sfFDN::GenerateMatrix (uint32_t mat_size, ScalarMatrixType type, uint32_t seed=0, std::optional< float > arg=std::nullopt)
	Generates a square matrix of size mat_size x mat_size based on the specified type.
std::vector< float >	sfFDN::NestedAllpassMatrix (uint32_t mat_size, uint32_t seed=0, std::span< float > input_gains=std::span< float >(), std::span< float > output_gains=std::span< float >())
	Generates a nested allpass matrix of size mat_size x mat_size as described in [1].

Detailed Description

A collection of functions to generate various types of feedback matrices.

Function Documentation

GenerateMatrix()

std::vector< float > sfFDN::GenerateMatrix	(	uint32_t	mat_size,
		ScalarMatrixType	type,
		uint32_t	seed = 0,
		std::optional< float >	arg = std::nullopt )

Generates a square matrix of size mat_size x mat_size based on the specified type.

Parameters

mat_size	The size of the matrix (number of rows and columns).
type	The type of matrix to generate.
seed	Seed for random number generation (used for Random and RandomHouseholder types).
arg	Optional argument for certain matrix types.

Returns

A flat vector containing the matrix elements in col-major order.

For the VariableDiffusion type, the optional argument 'arg' specifies the sparsity level (0 <= arg <= 1).

Adapted from the implementation in the FDNTB toolbox by S. J. Schlecht: https://github.com/SebastianJiroSchlecht/fdnToolbox/blob/master/Generate/fdnMatrixGallery.m

NestedAllpassMatrix()

std::vector< float > sfFDN::NestedAllpassMatrix	(	uint32_t	mat_size,
		uint32_t	seed = 0,
		std::span< float >	input_gains = std::span< float >(),
		std::span< float >	output_gains = std::span< float >() )

Generates a nested allpass matrix of size mat_size x mat_size as described in [1].

Parameters

mat_size	The size of the matrix (number of rows and columns). Must be a power of two.
seed	Seed for random number generation.
input_gains	[Optional|Out]: input gains for the allpass filters.
output_gains	[Optional|Out]: output gains for the allpass filters.

Returns

A flat vector containing the matrix elements in col-major order.

Note

[1] William G. Gardner; A real‐time multichannel room simulator. J. Acoust. Soc. Am. 1 October 1992; 92 (4_Supplement): 2395. https://doi.org/10.1121/1.404752