PolynomialFract32

Overview

Sample-by-sample polynomial nonlinearity

Discussion

Polynomial nonlinearity, computed on a sample by sample basis. The module implements the following equation:

$y[n]=x[n]^{N-1}c[0]+x[n]^{N-2}c[1]+...+x[n]c[N-2] + c[N-1]$

where y is the output, x is the input, and c is the array of polynomial coefficients.

Type Definition

CODE

typedef struct _ModulePolynomialFract32
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 numCoeffs;                              // Number of coefficients in the polynomial
    INT32 postShift;                              // Number of bits to shift
    FLOAT32* coeffs;                              // Coefficient array in descending order. X^(N-1)*C[0] + X^(N-2)*C[1]+ ...
    fract32* coeffsFract32;                       // Coefficient array in descending order. X^(N-1)*C[0] + X^(N-2)*C[1]+ ...
} ModulePolynomialFract32Class;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
numCoeffs	int	const	0	3	Unrestricted
postShift	int	derived	1	1	Unrestricted
coeffs	float*	parameter	0	[3 x 1]	Unrestricted
coeffsFract32	fract32*	derived	0	[3 x 1]	Unrestricted

Pins

Input Pins

Name: in

Description: audio input

Data type: fract32

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: audio output

Data type: fract32

MATLAB Usage

File Name: polynomial_fract32_module.m

CODE

 M=polynomial_fract32_module(NAME, NUMCOEFFS)
 Creates a sample-by-sample polynomial nonlinearity for us in the Audio
 Weaver environment.  The module has a single multi-channel input pin.
 Arguments:
    NAME - name of the module.
    NUMCOEFFS - number of coefficients in the polynomial.
 The order of the polynomial (the highest power of x) is NUMCOEFFS-1.
 The polynomial coefficients use the same ordering as the MATLAB
 polyval function.