y = filter(b,a,x)
[y,zf] = filter(b,a,x)
y = filter(b,a,x,zi)
filter
filters a data sequence using a digital filter. The filter realization is the transposed direct form II structure, which can handle both FIR and IIR filters [1].
y = filter(b,a,x)
filters the data in vector x
with the filter described by numerator coefficient vector b
and denominator coefficient vector a
to create the filtered data vector y
. If a(1) ~= 1
, filter
normalizes the filter coefficients by a(1)
. If a(1) = 0
, filter
returns an error.
[y,zf] = filter(b,a,x)
returns the final state values in vector zf
.
y = filter(b,a,x,zi)
specifies initial state conditions in vector zi
.
The size of the initial/final condition vector is max(size(a),size(b))
.
filter
works for both real and complex inputs.
filter
is implemented as a transposed direct form II structure,where n-1 is the filter order.
The operation of filter
at sample m is given by the time domain difference equations
The input-output description of this filtering operation in the z-transform domain is a rational transfer function,
filter2
filtic
in the Signal Processing Toolbox
(c) Copyright 1994 by The MathWorks, Inc.