Have a look at ?lines ?points ?plot - the option add, add=TRUE You will have to specify proper limits on both axes, otherwise you may only see parts of the graphs. Some functions in the survival library also allow stratified analyses in which case the plots account for different strata.
Petr Gregory Pierce napsal(a): > I should clarify. I can generate plots for each category individually but > not for all three on the same chart. > > Greg > > -----Original Message----- > From: Gregory Pierce [mailto:[EMAIL PROTECTED] > Sent: Wednesday, May 02, 2007 10:21 PM > To: '[email protected]' > Subject: Survival statistics--displaying multiple plots > > Hello all! > > I am once again analyzing patient survival data with chronic liver disease. > > The severity of the liver disease is given by a number which is continuously > variable. I have referred to this number as "meld"--model for end stage > liver disease--which is the result of a mathematical calculation on > underlying laboratory values. So, for example, I can generate a Kaplan-Meier > plot of patients undergoing a TIPS procedure with the following: > >> plot(survfit(Surv(days,status==1),subset(tips,meld<10)) > > where "tips" is my data set, "days" is the number of days alive, and meld is > the meld score. > > What I would like to do is display the survival graphs of patients with > meld<10, 10<meld<20, and meld>20. I am unsure about how to go about this. > > Any suggestions would be appreciated. > > Greg > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Petr Klasterecky Dept. of Probability and Statistics Charles University in Prague Czech Republic ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
