Admin Production ni-theme
Current Publication

InvCh_LPF

LabWindows/CVI

InvCh_LPF

Advanced Analysis Library Only

AnalysisLibErrType InvCh_LPF (double inputArray[], ssize_t numberOfElements, double samplingFrequency, double cutoffFrequency, double stopBandAttendb, int order, double outputArray[]);

Purpose

Filters the input array using an inverse Chebyshev lowpass digital filter. InvCh_LPF can perform the operation in place; that is, the input and output arrays can be the same.

Example Code

/* Generate a random signal and filter it using a fifth-order lowpass inverse Chebyshev filter. */
double x[256], y[256], fs, fc, atten;
ssize_t n;
int order;
n = 256;
fs = 1000.0;
fc = 200.0;
atten = 40.0;
order = 5;
Uniform (n, 17, x);
InvCh_LPF (x, n, fs, fc, atten, order, y);

Parameters

Input
Name Type Description
inputArray double [] Array containing the raw data to filter.
numberOfElements ssize_t Number of elements in both the input and output array.
samplingFrequency double The frequency in Hertz at which you want to sample inputArray. This value must be greater than 0.
cutoffFrequency double Cutoff frequency in Hertz. This value must be 0 < cutoffFrequency < 0.5 * samplingFrequency.
stopBandAtten_db double Stop band attenuation in decibels. This value must be greater than 0.

Default Value: 40.0 db.
order int Filter order. This value must be greater than 0.

Default Value: 5.
Output
Name Type Description
outputArray double [] Filtered data.

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