[R] Time data

Hello fellow R-users, I have a data set that includes times in the hh:mm format. I am uncertain how to tell R that it is time data. Currently when I try to calculate a mean with this time subset, I get an error message: > mean(mar2011stats$TT) [1] NA Warning message: In mean.default(mar2011stats$

Re: [R] Survival statistics--displaying multiple plots

hours now, and getting nowhere. I wish I were able to repay in some way. Thank you! Greg -Original Message- From: Marc Schwartz [mailto:[EMAIL PROTECTED] Sent: Thursday, May 03, 2007 12:18 AM To: Gregory Pierce Cc: [EMAIL PROTECTED] Subject: Re: [R] Survival statistics--displaying multi