\HeaderA{probesByLL}{A function that does reverse the mappings between probe ids and
the corresponding values}{probesByLL}
\keyword{manip}{probesByLL}
\begin{Description}\relax
This  function takes the name of a platform specific annotation data
package (e. g. "hgu95av2") and a character string for the name of an
environment stored in the data directory and returns a list of vectors of
character string with values of the environment as the names of the lists of
vectors and probe ids corresponding to the values of the environment
as values.
\end{Description}
\begin{Usage}
\begin{verbatim}
probesByLL(baseName, what = "ENTREZID")
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{baseName}] \code{baseName} a character string for the name of
platform specific annotation data package
\item[\code{what}] \code{what} a character string for the name of the
environment object, which is the last part of an environment name
excluding the package name
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
Each platform specific annotation data package has mappings between
probe ids to other values. This function does
reverse mappings by grouping probe ids under unique values of a given
environmentand returns the mappings as a list.

Values for the environment object for which the reverse mappings are
sought must be vectors.
\end{Details}
\begin{Value}
This function returns a list of vectors of character strings with
unique values of an environment as the names and probe ids
corresponding to the values as values.
\end{Value}
\begin{Author}\relax
Jianhua Zhang
\end{Author}
\begin{Examples}
\begin{ExampleCode}
    if(require("hgu95av2")){
        tt <- probesByLL("hgu95av2", "ENTREZID")
        tt[1:4]
    }
\end{ExampleCode}
\end{Examples}