Hello, I want to test if the Weibull distribution is appropriate for the failure time. When trying to reproduce an example from MASS (the book, Ch. 13.2), I type
library(survival) library(MASS) leuk.wei <- survreg( Surv(time)~ag+log(wbc),data=leuk) ntimes <- leuk$time*exp(-leuk.wei$linear.predictors) plot(survfit(Surv(ntimes)),log=T) and get (almost) the same graph as in the book (which means that the distribution is close to exponential). On the other hand, if I want to test for the Weibull distribution, the recommended command > plot(survfit(Surv(ntimes)),fun="cloglog") ends in an error message: Error in rep.default(2, n2 - 1) : invalid number of copies in rep() In addition: Warning message: 2 x values <= 0 omitted from logarithmic plot in: xy.coords(x, y, xlabel, ylabel, log) I'd appreciate any hints, Rem ______________________________________________ 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
