

    \filetitle{trend}{Estimate a time trend}{tseries/trend}

	\paragraph{Syntax}

\begin{verbatim}
X = trend(X,range)
\end{verbatim}

\paragraph{Input arguments}

\begin{itemize}
\item
  \texttt{X} {[} tseries {]} - Input time series.
\item
  \texttt{Range} {[} tseries {]} - Range for which the trend will be
  computed.
\end{itemize}

\paragraph{Output arguments}

\begin{itemize}
\itemsep1pt\parskip0pt\parsep0pt
\item
  \texttt{X} {[} tseries {]} - Output trend time series.
\end{itemize}

\paragraph{Options}

\begin{itemize}
\item
  \texttt{'break='} {[} numeric \textbar{} \emph{empty} {]} - Vector of
  breaking points at which the trend may change its slope.
\item
  \texttt{'connect='} {[} \emph{\texttt{true}} \textbar{} \texttt{false}
  {]} - Calculate the trend by connecting the first and the last
  observations.
\item
  \texttt{'diff='} {[} \texttt{true} \textbar{} \emph{\texttt{false}}
  {]} - Estimate the trend on differenced data.
\item
  \texttt{'log='} {[} \texttt{true} \textbar{} \emph{\texttt{false}} {]}
  - Logarithmise the input data, de-logarithmise the output data.
\item
  \texttt{'season='} {[} \texttt{true} \textbar{} \emph{\texttt{false}}
  \textbar{} \texttt{2} \textbar{} \texttt{4} \textbar{} \texttt{6}
  \textbar{} \texttt{12} {]} - Include deterministic seasonal factors in
  the trend.
\end{itemize}

\paragraph{Description}

\paragraph{Example}


