coeffs

Filter coefficients

Syntax

s = coeffs(sysobj)

s = coeffs(sysobj,'Arithmetic',arithType)

Description

s = coeffs(sysobj) returns the coefficients of filter System object™, sysobj, in the structure s.

s = coeffs(sysobj,'Arithmetic',arithType) returns filter coefficients for the filter System object sysobj with the arithmetic specified in arithType.

Examples

Coefficients of an FIR Halfband Interpolator

FIRHalfbandInterp = dsp.FIRHalfbandInterpolator('Specification',...
    'Filter order and transition width','FilterOrder',26);
C = coeffs(FIRHalfbandInterp);
C.Numerator

ans = 1×27

    0.0525         0   -0.0379         0    0.0537         0   -0.0771         0    0.1172         0   -0.2060         0    0.6345    1.0000    0.6345         0   -0.2060         0    0.1172         0   -0.0771         0    0.0537         0   -0.0379         0    0.0525

% Impulse response of the filter
fvtool(FIRHalfbandInterp,'impulse')

Input Arguments

sysobj — Input filter

filter System object

Input filter, specified as as one of the following filter System objects:

• dsp.AllpassFilter

• dsp.AllpoleFilter

• dsp.BiquadFilter

• dsp.CICCompensationDecimator

• dsp.CICCompensationInterpolator

• dsp.CoupledAllpassFilter

• dsp.FilterCascade

• dsp.FIRDecimator

• dsp.FIRFilter

• dsp.FIRHalfbandDecimator

• dsp.FIRHalfbandInterpolator

• dsp.FIRInterpolator

• dsp.FIRRateConverter

• dsp.FourthOrderSectionFilter

• dsp.HighpassFilter

• dsp.IIRFilter

• dsp.IIRHalfbandDecimator

• dsp.IIRHalfbandInterpolator

• dsp.LowpassFilter

• dsp.NotchPeakFilter

• dsp.VariableBandwidthFIRFilter

• dsp.VariableBandwidthIIRFilter

arithType — Arithmetic type

'double' (default) | 'single' | 'Fixed'

Specify the arithmetic used during analysis. When the arithmetic input is not specified and the filter System object is unlocked, the analysis tool assumes a double-precision filter. The 'Arithmetic' property set to 'Fixed' applies only to filter System objects with fixed-point properties.

Output Arguments

s — Structure

struct

Structure with a single field, Numerator, containing filter coefficients.