hd = dfilt.allpass(c)
hd = dfilt.allpass(c) constructs
an allpass filter with the minimum number of multipliers from the
elements in vector
c. To be valid,
contain one, two, three, or four real elements. The number of elements
c determines the order of the filter. For example,
two elements creates a second-order filter and
four elements creates a fourth-order filter.
The transfer function for the allpass filter is defined by
given the coefficients in
To construct a cascade of allpass filter objects, use
For more information about creating cascades of allpass filters, refer
The following table provides a list of all the properties associated
with an allpass
Contains the coefficients for the allpass filter object
Describes the signal flow for the filter object, including all of the active elements that perform operations during filtering — gains, delays, sums, products, and input/output.
Specifies whether to reset the filter states and memory
before each filtering operation. Lets you decide whether your filter
retains states from previous filtering runs.
This property contains the filter states before, during,
and after filter operations. States act as filter memory between filtering
runs or sessions. They also provide linkage between the sections of
a multisection filter, such as a cascade filter. For details, refer
This example constructs and displays the information about a second-order allpass filter that uses the minimum number of multipliers.
c = [1.5, 0.7]; % Create a second-order dfilt object. hd = dfilt.allpass(c);