new function to choose p2

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/correg@295 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
more features

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/correg@296 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
changing default value

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/correg@297 edb9625f-4e0d-4859-8d74-9fd3b1da38cb