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CxBssl_LPF

LabWindows/CVI

CxBssl_LPF

Advanced Analysis Library Only

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

Purpose

Filters the complex input array using a Bessel lowpass digital filter. CxBssl_LPF can perform the operation in place; that is, the input and output arrays can be the same.

Example Code

/* Generate a random complex signal and filter it using a fifth-order lowpass Bessel filter. */
NIComplexNumber x[256];
double input[256];
double fs, fc;
ssize_t n;
int order;
int status;
int i;

n = 256;
fs = 1000.0;
fc = 200.0;
order = 5;
WhiteNoise (n, 1, 17, input);
for(i = 0; i < n; i++){

x[i].real = input[i];
x[i].imaginary = input[i];

}
status = CxBssl_LPF (x, n, fs, fc, order, NULL);

Parameters

Input
Name Type Description
inputArray NIComplexNumber [] 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 of the filter in Hertz. This value must be 0 < cutoffFrequency < 0.5 * samplingFrequency. This value must be 0 < cutoffFrequency < 0.5 * samplingFrequency.
order int Filter order. This value must be greater than 0.

Default Value: 5.
Output
Name Type Description
outputArray NIComplexNumber [] 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 2012 and later