Apply lag operator polynomial to filter time series
[
Y
,times
]
= filter(A
,X
)
[Y
,times
]
= filter(A
,X
,'Initial',X0
)
Given a lag operator polynomial A(L), [
applies A(L) to
time series data X(t). This is equivalent to applying
a linear filter to X(t), producing the filtered
output series Y(t) = A(L)X(t).Y
,times
]
= filter(A
,X
)
[
applies A(L) to
time series data X(t) with specified presample
values of the input time series X(t).Y
,times
]
= filter(A
,X
,'Initial',X0
)

Lag operator polynomial object, as produced by 



Presample values of the input time series X(t).
If 

Filtered input time series, Y(t) = A(L)X(t). 

Vector of relative time indices the same length as 
Filtering is limited to single paths, so matrix data are assumed to be a single path of a multidimensional process, and 3D data (multiple paths of a multidimensional process) are not allowed.