2010/2/18 Philipp Rappold <philipp.rapp...@gmail.com>: > Dear all, > > does anyone know how I can extract specific p-values for covariates from an > aftreg object? After fitting a model with aftreg I can find all different > variables by using str(), but there's no place where p-values are kept. The > odd thing is that print() displays them correctly. > > EXAMPLE: > >> testdata > start stop censor groupvar var1 var2 > 1 0 1 0 1 0.91663902 0.0847912 > 2 1 2 0 1 0.60470753 0.6487798 > 3 2 3 0 1 0.09599891 0.2195178 > 4 3 4 1 1 0.86384189 0.6667897 > 5 0 1 0 2 0.07747445 0.8782836 > 6 1 2 0 2 0.44608030 0.2218685 > 7 2 3 1 2 0.77317152 0.3813840 > > >> fit1 <- aftreg(Surv(start, stop, censor)~var1, data=testdata) > > >> fit1 > Call: > aftreg(formula = Surv(start, stop, censor) ~ var1, data = testdata) > > Covariate W.mean Coef Exp(Coef) se(Coef) Wald p > var1 0.540 0.150 1.162 0.770 0.845 > > log(scale) 1.358 3.890 0.260 0.000 > log(shape) 2.015 7.502 0.781 0.010 > > Events 2 > Total time at risk 7 > Max. log. likelihood -1.4026 > LR test statistic 0.05 > Degrees of freedom 1 > Overall p-value 0.816436 > WALD P IS DISPLAYED CORRECTLY. > > > Any help is highly appreciated, I'm going nuts here ;)
print.aftreg calculates the p-values like this: pchisq(x$coef^2 / diag(x$var), 1, lower.tail = FALSE) where x is the output from 'aftreg'. You could try the same. Thanks > Philipp > > ______________________________________________ > 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. > -- Göran Broström ______________________________________________ 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.