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IIRFiltering

LabWindows/CVI

IIRFiltering

Advanced Analysis Library Only

AnalysisLibErrType IIRFiltering (double xArray[], ssize_t numberOfXElements, double aCoefficientArray[], double y1[], int numberOfACoefficients, double bCoefficientArray[], double x1[], int numberOfBCoefficients, double yArray[]);

Purpose

Filters the input sequence using the IIR filter specified by reverse coefficients aCoefficientArray and forward coefficients bCoefficientArray using the following formula:

The reverse and forward coefficients are obtained by respective IIR coefficient functions, such as Bw_Coef.

Parameters

Input
Name Type Description
xArray double [] Array containing the raw data to filter.
numberOfXElements ssize_t Number of points in both bCoefficientArray and xConditionsArray.
aCoefficientArray double [] Array that contains the reverse coefficients for the IIR filtering operation.
yConditionsArray double [] Array that contains the initial conditions, or states. The size of this array must be at least numberACoefficients – 1.

On output, yConditionsArray contains the final conditions for the next iterations.
numberOfACoefficients int Number of coefficients in both aCoefficientArray and yConditionsArray.
bCoefficientArray double [] Array that contains the forward coefficients for the IIR filtering operation.
xConditionsArray double [] Array that contains the initial conditions, or states. The size of this array must be at least bCoefficientArray – 1.

On output, xConditionsArray contains the final conditions for the next iterations.
numberOfBCoefficients int Number of coefficients in both bCoefficientArray and xConditionsArray.
Output
Name Type Description
yArray double [] The output of the IIR filtering operation. The size of this array must be at least numberXElements.

Return Value

Name Type Description
status AnalysisLibErrType A value that specifies the type of error that occurred. Refer to analysis.h for definitions of these constants.

Additional Information

Library: Advanced Analysis Library

Include file: analysis.h

LabWindows/CVI compatibility: LabWindows/CVI 3.1 and later