Overview

pdf of data

Discussion

The PDF module builds a histogram of incoming data and allows you to freeze the histogram with an input pin. It also provides optional smoothing as well as an optional reset pin. A histogram is a graphical representation showing a visual impression of the distribution of data values. A histogram is essentially a table in which each entry represents the number of times that the input sample values fell in a particular range.

Unlike the Histogram module, the PDF module calculates the bin spacing based on the higherBinEdge and lowerBinEdge variables ((higherBinEdge - lowerBinEdge) / numBins). Set these variables to change the bin spacing of your PDF module’s histogram.

Connect an audio signal that you wish to analyze by wiring into input pin 1.

Conenct a BooleanSource module to the freeze pin and toggle to freeze the histogram in its current state.

(OPTIONAL) Enable the reset pin in the Arguments tab. Connect a BooleanSource module to the optional reset pin to clear the histogram data.

Type Definition

typedef struct _ModulePDF
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 numBins;                                // Number of bins
    INT32 controllableResetPin;                   // Controlling Reset Pin
    FLOAT32 lowerBinEdge;                         // Specifies the lowest bin in the histogram
    FLOAT32 higherBinEdge;                        // Specifies the highest bin in the histogram
    FLOAT32 smoothingTime;                        // The smoothing time of the PDF in ms
    FLOAT32 alpha;                                // Forgetting factor
    FLOAT32 binSpacing;                           // BinSpacing
    INT32 reset;                                  // Boolean parameter to reset the pdf.
    FLOAT32* binCenter;                           // indices
    FLOAT32* previousOut;                         // previous output.
    INT32* hist;                                  // init hist.
} ModulePDFClass;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
numBins	int	const	0	32	Unrestricted
controllableResetPin	int	const	0	1	Unrestricted
lowerBinEdge	float	parameter	0	-1	Unrestricted
higherBinEdge	float	parameter	0	1	Unrestricted
smoothingTime	float	parameter	0	1000	0:10000
alpha	float	derived	0	0.0006664	Unrestricted
binSpacing	float	derived	0	0.0625	Unrestricted
reset	int	parameter	0	0	0:1
binCenter	float*	derived	0	[32 x 1]	Unrestricted
previousOut	float*	state	0	[32 x 1]	Unrestricted
hist	int*	state	0	[32 x 1]	Unrestricted

Pins

Input Pins

Name: in

Description: Audio input

Data type: float

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Name: freeze

Description: input freeze

Data type: int

Channel range: 1

Block size range: 1

Sample rate range: Unrestricted

Complex support: Real

Name: reset

Description: input reset

Data type: int

Channel range: 1

Block size range: 1

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: Audio output

Data type: float

MATLAB Usage

File Name: pdf_module.m