digitalFilter class

Digital filter

Description

• Use designfilt in the form d = designfilt(resp,Name,Value) to design a digital filter, d, with response type resp. Specify the filter further using a set of Name,Value pairs.

• Use designfilt in the form designfilt(d) to edit an existing filter, d.

  Note

  This is the only way to edit a digitalFilter object. Its properties are otherwise read-only.

• Use filter in the form dataOut = filter(d,dataIn) to filter a signal with a digitalFilter, d. The input can be a double- or single-precision vector. It can also be a matrix with as many columns as there are input channels.

• Use fvtool to visualize a digitalFilter, d.

• The following functions take digitalFilter objects as input.

Filtering and Analysis Functions

Filtering

Function	Description
fftfilt	Filters a signal with a digitalFilter using an FFT-based overlap-add method
filter	Filters a signal using a digitalFilter
filtfilt	Performs zero-phase filtering of a signal with a digitalFilter

Filter Analysis

Function	Description
double	Casts the coefficients of a digitalFilter to double precision
filt2block	Generates a Simulink® filter block corresponding to a digitalFilter
filtord	Returns the filter order of a digitalFilter
firtype	Returns the type (1, 2, 3, or 4) of an FIR digitalFilter
freqz	Returns or plots the frequency response of a digitalFilter
fvtool	Opens the Filter Visualization Tool and displays the magnitude response of a digitalFilter
grpdelay	Returns or plots the group delay response of a digitalFilter
impz	Returns or plots the impulse response of a digitalFilter
impzlength	Returns the length of the impulse response of a digitalFilter, whether actual (for FIR filters) or effective (for IIR filters)
info	Returns a character array with information about a digitalFilter
isallpass	Returns true if a digitalFilter is allpass
isdouble	Returns true if the coefficients of a digitalFilter are double precision
isfir	Returns true if a digitalFilter has a finite impulse response
islinphase	Returns true if a digitalFilter has linear phase
ismaxphase	Returns true if a digitalFilter is maximum phase
isminphase	Returns true if a digitalFilter is minimum phase
issingle	Returns true if the coefficients of a digitalFilter are single precision
isstable	Returns true if a digitalFilter is stable
phasedelay	Returns or plots the phase delay response of a digitalFilter
phasez	Returns or plots the (unwrapped) phase response of a digitalFilter
single	Casts the coefficients of a digitalFilter to single precision
ss	Returns the state-space representation of a digitalFilter
stepz	Returns or plots the step response of a digitalFilter
tf	Returns the transfer function representation of a digitalFilter
zerophase	Returns or plots the zero-phase response of a digitalFilter
zpk	Returns the zero-pole-gain representation of a digitalFilter
zplane	Displays the poles and zeros of the transfer function represented by a digitalFilter