\HeaderA{aRTlayer-getSetMetric}{Set Metrics}{aRTlayer.Rdash.getSetMetric}
\aliasA{difference}{aRTlayer-getSetMetric}{difference}
\aliasA{getSetMetric}{aRTlayer-getSetMetric}{getSetMetric}
\aliasA{getSetMetric,aRTlayer-method}{aRTlayer-getSetMetric}{getSetMetric,aRTlayer.Rdash.method}
\aliasA{intersection}{aRTlayer-getSetMetric}{intersection}
\aliasA{union}{aRTlayer-getSetMetric}{union}
\aliasA{xor}{aRTlayer-getSetMetric}{xor}
\keyword{connection}{aRTlayer-getSetMetric}
\begin{Description}\relax
Return the result of a metric evolving set operations (union, intersection, difference and xor).
\end{Description}
\begin{Usage}
\begin{verbatim}
## S4 method for signature 'aRTlayer':
getSetMetric(object, metric, ids=c("1","2","3"))
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{object}] Object of class \code{aRTlayer}.
\item[\code{metric}] A set metric among:
\item[\code{ids}] The ids which to be used in the operation. Metrics \code{difference} and \code{xor}
use only two ids.
\end{ldescription}
\end{Arguments}
\begin{Author}\relax
Pedro Ribeiro de Andrade Neto
\end{Author}
\begin{SeeAlso}\relax
See \code{aRTlayer-class} to the description of this class.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
## Not run: 
## difference between two geometries
getSetMetric(layer, "difference", ids=c("1", "2"))

## union of all geometries of the layer
getSetMetric(layer, "union", ids=getGeometry(layer)$id)
## End(Not run)
\end{ExampleCode}
\end{Examples}

