Initial conditions for transposed direct-form II filter implementation
If any of the input arguments y
, x
,
b
, or a
is not a vector (that is, if any argument
is a scalar or array), filtic
gives the following error message:
Requires vector inputs.
filtic
performs a reverse difference equation to obtain the delay
states z
. Elements of x
beyond x(n-1)
and elements of y
beyond y(m-1)
are unnecessary so
filtic
ignores them.
The transposed direct-form II structure is shown in the following illustration.
n – 1 is the filter order.
[1] Oppenheim, A.V., and R.W. Schafer, Discrete-Time Signal Processing, Prentice-Hall, 1989, pp. 296, 301-302.