# WindFIR_Filter

Advanced Analysis Library Only

AnalysisLibErrType WindFIR_Filter (int filterType, double samplingFrequency, double lowerCutoffFreq, double upperCutoffFreq, int numberOfCoefficients, int windowType, double windowParameter, double coefficients[]);

## Purpose

Generates windowed FIR filter coefficients. This function computes only FIR coefficients. You can call a convolution function on the computed coefficients and the signal to perform actual data filtering.

## Parameters

Input
Name | Type | Description
filterType | integer | The type of filter. filterType must be one of the following values: LOWPASS (0) HIGHPASS (1) BANDPASS (2) BANDSTOP (3)
samplingFrequency | double-precision | Sampling frequency, in Hz.
lowerCutoffFreq | double-precision | The cutoff frequency for LOWPASS or HIGHPASS filters, or the low cutoff frequency for BANDPASS or BANDSTOP filters, in Hz.
upperCutoffFreq | double-precision | The high cutoff frequency for BANDPASS or BANDSTOP filters. This parameter is not referenced if filterType is LOWPASS or HIGHPASS.
numberOfCoefficients | integer | The total number of FIR filter coefficients.
windowType | integer | The type of window to apply. windowType must be one of the following values: RECTANGLE (0) HANNING (1) HAMMING (2) BLKHARRIS (3) EXBLKMAN (4) BLKMAN (5) FLATTOP (6) BH4TERM (7) BH7TERM (8) LOWSIDELB (9) BLKMANNUTTALL (11) TRIANGLE (30) KAISER (60) DOLCHEBYSHEV (61) GAUSSIAN (62)
windowParameter | double-precision | The window parameter. This parameter is referenced only if windowType is one of the following values: KAISER: para is beta. GAUSSIAN: para is the standard deviation. If para < 0, the function uses 0.2 for para instead. DOLCHEBYSHEV: para is the ratio of the mainlobe to the sidelobe, in dB. If para < 0, the function uses 60dB for para instead.
Output
Name | Type | Description
coefficients | double-precision array | The computed windowed FIR coefficients.

## 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.