Dear R-helpers: I am trying to fit a multivariate Cox proportional hazards model, modelling survival outcome as a function of treatment and receptor status. The data look like below:
# structure of the data str(sample.data) List of 4 $ survobj : Surv [1:129, 1:2] 0.8925+ 1.8836+ 2.1191+ 5.3744+ 1.6099+ 5.2567 0.2081+ 0.2108+ 0.2683+ 0.4873+ ... ..- attr(*, "dimnames")=List of 2 .. ..$ : NULL .. ..$ : chr [1:2] "time" "status" ..- attr(*, "type")= chr "right" $ therapy : Factor w/ 2 levels "treatment1","treatment2": 1 1 1 1 1 1 1 2 2 1 ... $ ReceptorA: Factor w/ 2 levels "0","1": 1 2 2 2 1 2 2 2 2 1 ... $ ReceptorB: Factor w/ 2 levels "0","1": 1 2 1 1 2 1 1 1 1 1 ... But when I tried to fit a multivariate Cox proportional model, I got the following error. I'm not quite what that means. Any help would be much appreciated! # perform multivariate Cox proportional hazards model coxph(sample.data$survobj ~ sample.data$therapy + sample.data$ReceptorA + sample.data$ReceptorB) Error in fitter(X, Y, strats, offset, init, control, weights = weights, : NA/NaN/Inf in foreign function call (arg 6) In addition: Warning message: In fitter(X, Y, strats, offset, init, control, weights = weights, : Ran out of iterations and did not converge Best regards, Cindy -- output of sessionInfo(): sessionInfo() R version 2.15.2 (2012-10-26) Platform: x86_64-unknown-linux-gnu (64-bit) locale: [1] C attached base packages: [1] grid splines stats graphics grDevices datasets utils [8] methods base other attached packages: [1] MASS_7.3-23 [2] hexbin_1.26.1 [3] cluster_1.14.3 [4] latticeExtra_0.6-24 [5] RColorBrewer_1.0-5 [6] lattice_0.20-13 [7] survival_2.37-2 loaded via a namespace (and not attached): [1] tools_2.15.2 ______________________________________________ R-help@r-project.org 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.
