\name{getxy.probeseq}
\alias{getxy.probeseq}
%- Also NEED an '\alias' for EACH other topic documented here.
\title{ A function to get the XY coordinates from a probes sequences
  data frame}
\description{
 A function to get the XY coordinates from a probes sequences \code{data.frame}
}
\usage{
getxy.probeseq(ppset.id = NULL, probeseq = NULL, i.row = NULL,
xy.offset = NULL, x.colname = "x", y.colname = "y")
}
%- maybe also 'usage' for other objects documented here.
\arguments{
  \item{ppset.id}{ The probe sets of interest (a vector of mode \code{character}. }
  \item{probeseq}{ The probe sequence \code{data.frame} (see details). }
  \item{i.row}{ Row indexes in the \code{data.frame} (see details). }
  \item{xy.offset}{ Offset for the xy coordinates. if \code{NULL}, uses
    the default offset stored as an option for the affy package. }
  \item{x.colname, y.colname}{ The probe sequence packages have seen the
    names for the columns in their \code{data.frame}. This parameters
    exists to let us follow these changes.}
}
\details{
  The \code{data.frame} passed as argument \code{probeseq} is expected
  to have (at least) the following columns: \code{Probe.X},
  \code{Probe.Y} and \code{Probe.Set.Name}. When the argument
  \code{ppset.id} is not null, the probe sets
}
\value{
A \code{matrix} of two columns. The first column contains x coordinates,
while the second column contains y coordinates.
}
\author{ Laurent }

\section{Warning }{
  The parameter \code{xy.offset.one} is here for historical
  reasons. This should not be touched, the option in the affy
  package should be modified if one wishes to modify this.
  
  This function should not be confused with the methods \code{index2xy}
  and similar. Here the the XY coordinate come from a \code{data.frame}
  that stores information about an arbitrary number probes on the
  chip. (See the `probe sequence' data packages on Bioconductor, and the
  package \code{Biostrings}).
  
  The methods \code{index2xy} are meant to interact with instances of
  class \code{AffyBatch}.
}

%\seealso{ ~~objects to See Also as \code{\link{~~fun~~}}, ~~~ }
\examples{
##---- Should be DIRECTLY executable !! ----
}
\keyword{ manip }