dfilt.cascade
Cascade of discrete-time filters
Syntax
hd = dfilt.cascade(filterobject1,filterobject2,...)
Description
hd = dfilt.cascade(filterobject1,filterobject2,...) returns
a discrete-time filter object hd of type cascade,
which is a serial interconnection of two or more filter objects filterobject1, filterobject2,
and so on. dfilt.cascade accepts any combination
of dfilt objects (discrete time filters) to cascade,
as well as Farrow filter objects.
You can use the standard notation to cascade one or more filters:
cascade(hd1,hd2,...)
where hd1, hd2, and so
on can be mixed types, such as dfilt objects and
other filtering objects.
hd1, hd2, and so on can
be fixed-point filters. All filters in the cascade must be the same
arithmetic format — double, single,
or fixed. hd, the filter object
returned, inherits the format of the cascaded filters.
Examples
Cascade a lowpass filter and a highpass filter to produce a bandpass filter.
[b1,a1]=butter(8,0.6); % Lowpass [b2,a2]=butter(8,0.4,'high'); % Highpass h1=dfilt.df2t(b1,a1); h2=dfilt.df2t(b2,a2); hcas=dfilt.cascade(h1,h2); % Bandpass with passband 0.4-0.6 % View stage 1 with hcas.Stage(1)