Digital Filtering

Use digital filtering to remove unwanted parts of a digital signal such as noise. LabWindows/CVI provides both finite impulse response (FIR) and infinite impulse response (IIR) filters.

The LabWindows/CVI Advanced Analysis Library includes the following digital filtering functions:

Function Description
AllocIIRFilterPtr Allocates and initializes the filter information structure, which is used with the IIR cascade filter coefficient design calls.
Bessel_CascadeCoef Generates the set of cascade form filter coefficients to implement an IIR filter as specified by the Bessel filter model.
Bessel_Coef Generates the set of filter coefficients to implement an IIR filter as specified by the Bessel filter model.
Bw_BPF Filters the input array using a Butterworth bandpass digital filter.
Bw_BSF Filters the input array using a Butterworth bandstop digital filter.
Bw_CascadeCoef Generates the set of cascade form filter coefficients to implement an IIR filter as specified by the Butterworth filter model.
Bw_Coef Generates the set of filter coefficients to implement an IIR filter as specified by the Butterworth filter model.
Bw_HPF Filters the input array using a Butterworth highpass digital filter.
Bw_LPF Filters the input array using a Butterworth lowpass digital filter.
CascadeToDirectCoef Converts from cascade IIR coefficients to direct-form IIR coefficients.
Ch_BPF Filters the input array using a Chebyshev bandpass digital filter.
Ch_BSF Filters the input array using a Chebyshev bandstop digital filter.
Ch_CascadeCoef Generates the set of cascade form filter coefficients to implement an IIR filter as specified by the Chebyshev filter model.
Ch_Coef Generates the set of filter coefficients to implement an IIR filter as specified by the Chebyshev filter model.
Ch_HPF Filters the input array using a Chebyshev highpass digital filter.
Ch_LPF Filters the input array using a Chebyshev lowpass digital filter.
Elp_BPF Filters the input array using an elliptic bandpass digital filter.
Elp_BSF Filters the input array using an elliptic bandstop digital filter.
Elp_CascadeCoef Generates the set of cascade form filter coefficients to implement an IIR filter as specified by the elliptic (or Cauer) filter model.
Elp_Coef Generates the set of filter coefficients to implement an IIR filter as specified by the elliptic (or Cauer) filter model.
Elp_HPF Filters the input array using an elliptic highpass digital filter.
Elp_LPF Filters the input array using an elliptic lowpass digital filter.
Equi_Ripple Designs a multiband FIR linear phase filter, a differentiator, or a Hilbert Transform using the Parks-McClellan algorithm.
EquiRpl_BPF Designs an optimal bandpass FIR linear phase filter using the Parks-McClellan algorithm.
EquiRpl_BSF Designs a bandstop FIR linear phase filter using the Parks-McClellan algorithm.
EquiRpl_HPF Designs an optimal highpass FIR linear phase filter using the Parks-McClellan algorithm.
EquiRpl_LPF Designs an optimal lowpass FIR linear phase filter using the Parks-McClellan algorithm.
FIR_Coef Generates a set of FIR filter coefficients based on the window design method.
FreeIIRFilterPtr Frees the IIR cascade filter structure and all internal arrays.
IIRCascadeFiltering Filters the input sequence using the specified cascade IIR filter.
IIRFiltering Filters the input sequence using the specified IIR filter.
InvCh_BPF Filters the input array using an inverse Chebyshev bandpass digital filter.
InvCh_BSF Filters the input array using an inverse Chebyshev bandstop digital filter.
InvCh_CascadeCoef Generates the set of cascade form filter coefficients to implement an IIR filter as specified by the inverse Chebyshev filter model.
InvCh_Coef Generates the set of filter coefficients to implement an IIR filter as specified by the inverse Chebyshev filter model.
InvCh_HPF Filters the input array using an inverse Chebyshev highpass digital filter.
InvCh_LPF Filters the input array using an inverse Chebyshev lowpass digital filter.
Ksr_BPF Designs a digital bandpass FIR linear phase filter using a Kaiser window.
Ksr_BSF Designs a digital bandstop FIR linear phase filter using a Kaiser window.
Ksr_HPF Designs a digital highpass FIR linear phase filter using a Kaiser window.
Ksr_LPF Designs a digital lowpass FIR linear phase filter using a Kaiser window.
ResetIIRFilter Resets the internal filter state information to zero before the next cascade IIR filtering operation.
WindFIR_Filter Generates windowed FIR filter coefficients.