\name{hwgcodENSEMBL}
\alias{hwgcodENSEMBL}
\alias{hwgcodENSEMBL2PROBE}
\title{Map Ensembl gene accession numbers with Entrez Gene identifiers}  
\description{ 
  hwgcodENSEMBL is an R object that contains mappings between 
  Entrez Gene identifiers and Ensembl gene accession numbers.    
}
\details{
  This object is a simple mapping of Entrez Gene identifiers
  \url{http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=gene} to Ensembl
  gene Accession Numbers.

  Mappings were based on data provided by BOTH of these sources:
  \url{http://www.ensembl.org/biomart/martview/}
  \url{ftp://ftp.ncbi.nlm.nih.gov/gene/DATA}

  This mapping is a combination of NCBI to ensembl IDs from BOTH NCBI
  and ensembl.  Users who wish to only use mappings from NCBI are
  encouraged to see the ncbi2ensembl table in the appropriate organism
  package.  Users who wish to only use mappings from ensembl are
  encouraged to see the ensembl2ncbi table which is also found in the
  appropriate organism packages.  These mappings are based upon the ensembl
  table which is contains data from BOTH of these sources in an effort
  to maximize the chances that you will find a match.

  Mappings were based on data provided by: Entrez Gene  
  ftp://ftp.ncbi.nlm.nih.gov/gene/DATA  
  With a date stamp from the source of: 2012-Mar7
}

\examples{
    x <- hwgcodENSEMBL
    # Get the entrez gene IDs that are mapped to an Ensembl ID
    mapped_genes <- mappedkeys(x)
    # Convert to a list
    xx <- as.list(x[mapped_genes])
    if(length(xx) > 0) {
      # Get the Ensembl gene IDs for the first five genes
      xx[1:5]
      # Get the first one
      xx[[1]]
    }
    #For the reverse map ENSEMBL2PROBE:
    # Convert to a list
    xx <- as.list(hwgcodENSEMBL2PROBE)
    if(length(xx) > 0){
       # Gets the entrez gene IDs for the first five Ensembl IDs
       xx[1:5]
       # Get the first one
       xx[[1]]
    }
}
\keyword{datasets}