Create new variables
An embedded and charset-unspecified text was scrubbed... Name: not available URL: <https://stat.ethz.ch/pipermail/r-sig-teaching/attachments/20120320/a188f1fd/attachment.pl>
An embedded and charset-unspecified text was scrubbed... Name: not available URL: <https://stat.ethz.ch/pipermail/r-sig-teaching/attachments/20120320/a188f1fd/attachment.pl>