\name{Match}
\alias{Match}
%- Also NEED an '\alias' for EACH other topic documented here.
\title{Value Matching}
\description{
  'Match' returns a vector of the positions of (first) matches of
  its first argument in its second.

  Second must be an element of class segSet (or a numeric matrix with
  2 columns) ordered and without overlapping segments (function
  or.segSet is designed for this purpose).
}
\usage{
Match(x, a)
}

\arguments{
  \item{x}{a vector of positions}
  \item{a}{an element of class segSet}
}

\value{
  a vector of same size a x. Values are indices corresponding to element
  'a', 0 when no segment found.
}

\note{This can be used for a texture, when we know only regions,
  described by set of segments.}

\author{Antoine Lucas}

\examples{
a = matrix(c(1,30,40,50,60,70,80,110),ncol=2,byrow=TRUE)
a = or.segSet(a)

## show a:
a

Match(1:40,a)

## texture sample:
b  = matrix(c(15,18, 28,45,
                   1,10, 15,20, 25,40,
                   17,23, 35,38,100,105,
                   110,120),ncol=2,byrow=TRUE)
b = or.segSet(b)

texture = ( Match(1:120,a)>0 ) + ( Match(1:120,b)>0 )*2

## change numbers to colors

texture <- as.factor(texture)
levels(texture) <- c("red","blue","green","yellow")
texture <- as.character(texture)

plot(1:120,rep(1,120),col=as.character(texture))



}
\keyword{utilities}