Thank you guys. But I tried the commands and I still get: > aml1<-aml[aml$group==1,] > aml1 [1] time status x <0 rows> (or 0-length row.names) > esf.fit <- survfit(Surv(aml1$weeks,status) ~ 1) Error in Surv(aml1$weeks, status) : Time variable is not numeric In addition: Warning message: is.na() applied to non-(list or vector) in: is.na(time)
which still looks confusing. Or are they should be applied in s-plus instead of R? Thanks a lot! Linda -----Original Message----- From: Marc Schwartz [mailto:[EMAIL PROTECTED] Sent: Friday, January 20, 2006 4:49 PM To: Thomas Lumley Cc: Linda Lei; R-help@stat.math.ethz.ch Subject: Re: [R] command in survival package On Fri, 2006-01-20 at 15:27 -0800, Thomas Lumley wrote: > On Fri, 20 Jan 2006, Linda Lei wrote: > > > Hi there, > > > > > > > > I have a question about one command sentence when I follow the example > > in the book of "Survival analysis in S": > > > > > aml1<-aml[aml$group==1] > > If this is really what the book says you should probably complain to the > author. However, if it says > aml1<-aml[aml$group==1,] > then you show type that instead. > > It is hard to be sure, because you don't say where the `aml' data set > comes from. It can't be the one in the survival package as this doesn't > have a variable called "group" > > > > > Thus, I couldn't keep going on the next command: > > > > esf.fit<-survfit(Surv(aml1,status)~1). > > > > This looks implausible as well. I would have expected something like > esf.fit<-survfit(Surv(time,status)~1, data=aml1) Correct on both accounts Thomas. The text in the book on page 26 appears as Linda posted. However, there is an errata document here: http://www.crcpress.com/e_products/downloads/download.asp?cat_no=C4088 which shows the corrected text as: aml1 <- aml[aml$group==1,] # Maintained group only esf.fit <- survfit(Surv(aml1$weeks,status) ~ 1) HTH, Marc Schwartz ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
