Hello guys this problem was never answered and I happened to come across the same problem , kindly help. This is a simple R program that I have been trying to run. I keep running into the "singular matrix" error. I end up with no sensible results. Can anyone suggest any changes or a way around this?
I am a total rookie when working with R. Thanks, Rasika > library(survival) Loading required package: splines > args(coxph) function (formula, data, weights, subset, na.action, init, control, method = c("efron", "breslow", "exact"), singular.ok = TRUE, robust = FALSE, model = FALSE, x = FALSE, y = TRUE, tt, ...) NULL > test1<-read.table("S:/FISHDO/03_Phase_I_Field_Work/Data_6_28_2011/Working Folder/R_files/4SondesJuly24.csv", header=T, sep=",") > sondes<-coxph(Surv(Start, Stop, Depart)~DOLoomis + DOI55 + DODamen, data=test1) Warning messages: 1: In fitter(X, Y, strats, offset, init, control, weights = weights, : Loglik converged before variable 1,2 ; beta may be infinite. 2: In coxph(Surv(Start, Stop, Depart) ~ DOLoomis + DOI55 + DODamen, : X matrix deemed to be singular; variable 3 > summary(sondes) Call: coxph(formula = Surv(Start, Stop, Depart) ~ DOLoomis + DOI55 + DODamen, data = test1) n= 1737, number of events= 58 (1 observation deleted due to missingness) coef exp(coef) se(coef) z Pr(>|z|) DOLoomis -2.152e+00 1.163e-01 1.161e+05 0 1 DOI55 4.560e-01 1.578e+00 3.755e+04 0 1 DODamen NA NA 0.000e+00 NA NA exp(coef) exp(-coef) lower .95 upper .95 DOLoomis 0.1163 8.5995 0 Inf DOI55 1.5777 0.6338 0 Inf DODamen NA NA NA NA Concordance= 0.5 (se = 0 ) Rsquare= 0 (max possible= 0.01 ) Likelihood ratio test= 0 on 2 df, p=1 Wald test = 0 on 2 df, p=1 Score (logrank) test = 0 on 2 df, p=1 [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.