[R] use of "rcorr.cens" with binary response?

[Tom Vanwalleghem]

Dear R-helpers,

I recently switched from SAS to R, in order to model the occurrence of
rare events through logistic regression.
Is there a package available in R to calculate the Goodman-Kruskal
Gamma?
After searching a bit I found a function "rcorr.cens" which should do
the job, but it is not clear to me how to define the input vectors? Is
"x" a vector with the fitted probabilities and "s" a vector containing
the observed response variable? Or does anybody know an alternative?

Any help would be greatly appreciated,
Thanks,
Tom
--
Tom Vanwalleghem
Physical and Regional Geography, K.U.Leuven
Redingenstraat 16
B-3000 LEUVEN
+32(0)16/326414