\HeaderA{diffinv}{Discrete Integration: Inverse of Differencing}{diffinv}
\methaliasA{diffinv.default}{diffinv}{diffinv.default}
\methaliasA{diffinv.ts}{diffinv}{diffinv.ts}
\keyword{ts}{diffinv}
\begin{Description}\relax
Computes the inverse function of the lagged differences function
\code{\LinkA{diff}{diff}}.
\end{Description}
\begin{Usage}
\begin{verbatim}
diffinv(x, ...)

## Default S3 method:
diffinv(x, lag = 1, differences = 1, xi, ...)
## S3 method for class 'ts':
diffinv(x, lag = 1, differences = 1, xi, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x}] a numeric vector, matrix, or time series.
\item[\code{lag}] a scalar lag parameter.
\item[\code{differences}] an integer representing the order of the
difference.
\item[\code{xi}] a numeric vector, matrix, or time series containing the
initial values for the integrals.  If missing, zeros are used.
\item[\code{...}] arguments passed to or from other methods.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
\code{diffinv} is a generic function with methods for class \code{"ts"}
and \code{default} for vectors and matrices.

Missing values are not handled.
\end{Details}
\begin{Value}
A numeric vector, matrix, or time series (the latter for the
\code{"ts"} method) representing the discrete integral of \code{x}.
\end{Value}
\begin{Author}\relax
A. Trapletti
\end{Author}
\begin{SeeAlso}\relax
\code{\LinkA{diff}{diff}}
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
s <- 1:10
d <- diff(s)
diffinv(d, xi = 1)
\end{ExampleCode}
\end{Examples}

