filtic

(/tools/hpmatlab/toolbox/signal/filtic.m)

Function Synopsis

vinit = filtic( b, a, ypast, xpast )

Help text

FILTIC	Make initial conditions for 'filter' function.
	Z = filtic( B, A, Y, X ) converts past input X and output Y
	into initial conditions for the state variables Z needed in the
       TRANSPOSED DIRECT FORM II filter structure.
	The vectors of past inputs & outputs are stored with more recent
	values first, i.e.
          X = [ x[-1] x[-2] x[-3] ... x[-nb] ... ]
          Y = [ y[-1] y[-2] y[-3] ... y[-na] ... ]
	where nb = length(B)-1 and na = length(A)-1.  Short input vectors
	X and Y are zeropadded to length nb and na respectively.  If X
	or Y are longer than nb or na, the values beyond those lengths
	are irrelevant to the filter's initial conditions and are ignored.

	Z = filtic( B, A, Y ) assumes that X = 0 in the past.

	See also FILTER

Cross-Reference Information

end            /tools/hpmatlab/toolbox/matlab/lang/end.m
error          /tools/hpmatlab/toolbox/matlab/lang/error.m
filter         /tools/hpmatlab/toolbox/matlab/datafun/filter.m
if             /tools/hpmatlab/toolbox/matlab/lang/if.m
length         /tools/hpmatlab/toolbox/matlab/general/length.m
max            /tools/hpmatlab/toolbox/matlab/datafun/max.m
nargin         /tools/hpmatlab/toolbox/matlab/elmat/nargin.m
return         /tools/hpmatlab/toolbox/matlab/lang/return.m
size           /tools/hpmatlab/toolbox/matlab/general/size.m
sum            /tools/hpmatlab/toolbox/matlab/datafun/sum.m
zeros          /tools/hpmatlab/toolbox/matlab/elmat/zeros.m