R Under development (unstable) (2025-07-22 r88445 ucrt) -- "Unsuffered Consequences" Copyright (C) 2025 The R Foundation for Statistical Computing Platform: x86_64-w64-mingw32/x64 R is free software and comes with ABSOLUTELY NO WARRANTY. You are welcome to redistribute it under certain conditions. Type 'license()' or 'licence()' for distribution details. R is a collaborative project with many contributors. Type 'contributors()' for more information and 'citation()' on how to cite R or R packages in publications. Type 'demo()' for some demos, 'help()' for on-line help, or 'help.start()' for an HTML browser interface to help. Type 'q()' to quit R. > library(parfm) Loading required package: survival Loading required package: optimx > data(insem) > head(insem) Cowid Time Status Herd Ureum Protein Parity Heifer 1 1 82 1 1 3.12 3.22 6 0 2 2 80 1 1 6.60 3.02 5 0 3 3 152 1 1 3.97 2.74 5 0 4 4 287 1 1 4.04 3.00 4 1 5 5 236 1 1 3.33 3.30 4 0 6 6 83 1 1 3.19 3.50 4 0 > > insem$TimeMonths <- insem$Time * 12 / 365.25 > > set.seed(1) > insem <- insem[sample(1:nrow(insem), 150),] > parfm(Surv(TimeMonths, Status)~Heifer, cluster="Herd", data=insem, + dist="weibull", frailty="gamma") Frailty distribution: gamma Baseline hazard distribution: Weibull Loglikelihood: -328.14 ESTIMATE SE p-val theta 0.420 0.163 rho 1.698 0.143 lambda 0.114 0.025 Heifer -0.061 0.216 0.778 --- Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 Kendall's Tau: 0.173 > > proc.time() user system elapsed 5.50 0.54 6.03