warpArea.Rd

```
\name{warpArea}
\alias{warpArea}
\title{Compute Warping Path Area}
\description{
Compute the area between the warping function and the
diagonal (no-warping) path, in unit steps.
}
\usage{
warpArea(d)
}
\arguments{
\item{d}{an object of class \code{dtw}}
}
\value{
The area, not normalized by path length or else.
}
\details{
Above- and below- diagonal unit areas all count \emph{plus} one (they
do not cancel with each other). The "diagonal" goes from one corner to
the other of the possibly rectangular cost matrix, therefore having a
slope of \code{M/N}, not 1, as in \code{\link{slantedBandWindow}}.
The computation is approximate: points having multiple correspondences
are averaged, and points without a match are interpolated. Therefore,
the area can be fractionary.
}
\note{ There could be alternative definitions to the area, including
considering the envelope of the path. }
\examples{
ds<-dtw(1:4,1:8);
plot(ds);lines(seq(1,8,len=4),col="red");
warpArea(ds)
## Result: 6
## index 2 is 2 while diag is 3.3 (+1.3)
## 3 3 5.7 (+2.7)
## 4 4:8 (avg to 6) 8 (+2 )
## --------
## 6
}
\author{Toni Giorgino}
\concept{Warping Function Area}
\keyword{ts}
```