\name{append.psp}
\alias{append.psp}
\title{Combine Two Line Segment Patterns}
\description{
  Combine two line segment patterns into a single pattern.
}
\usage{
  append.psp(A, B)
}
\arguments{
  \item{A,B}{
    Line segment patterns (objects of class \code{"psp"}).
  }
}
\value{
  Another line segment pattern (object of class \code{"psp"}).
}
\details{
  This function is used to superimpose two line segment patterns
  \code{A} and \code{B}.
  
  The two patterns must have \bold{identical} windows. If one
  pattern has marks, then the other must also have marks
  of the same type.

  (To combine two point patterns, see \code{superimpose}).
}
\seealso{
  \code{\link{psp}},
  \code{\link{as.psp}},
  \code{\link{superimpose}},
}
\examples{
  X <- psp(runif(20), runif(20), runif(20), runif(20),  window=owin())
  Y <- psp(runif(5), runif(5), runif(5), runif(5),  window=owin())
  append.psp(X,Y)
}
\author{Adrian Baddeley
  \email{adrian@maths.uwa.edu.au}
  \url{http://www.maths.uwa.edu.au/~adrian/}
  and Rolf Turner
  \email{r.turner@auckland.ac.nz}
}
\keyword{spatial}
\keyword{manip}