########################################################################/**
 # @RdocFunction cdfOrderBy
 #
 # @title "Orders the fields according to the value of another field in the same CDF group"
 #
 # \description{
 #  @get "title".
 #
 #  This @function is design to be used with @see "applyCdfGroups"
 #  on an Affymetrix Mapping (SNP) CDF @list structure.
 # }
 #
 # @synopsis
 #
 # \arguments{
 #  \item{groups}{A @list of groups.}
 #  \item{field}{The field whose values are used to order the other fields.}
 #  \item{...}{Optional arguments passed @see "base::order".}
 # }
 #
 # \value{
 #  Returns a @list structure of groups.
 # }
 #
 # \seealso{
 #  @see "cdfOrderColumnsBy".
 #  @see "applyCdfGroups".
 # }
 #

 # @author "HB"

 #
 # @keyword programming
 # @keyword internal
 #**/#######################################################################
 cdfOrderBy <- function(groups, field, ...) {
   lapply(groups, function(group) {
     o <- order(.subset2(group, field), ...);
     lapply(group, FUN=.subset, o);
   })
 }
 
 ############################################################################
 # HISTORY:
 # 2006-04-20
 # o Created.
 ############################################################################