Dear R-help,
This is an example in the {Hmisc} manual under rcorr.cens function:
> set.seed(1)
> x <- round(rnorm(200))
> y <- rnorm(200)
> round(rcorr.cens(x, y, outx=F),4)
C Index Dxy S.D. n missing
uncensored Relevant Pairs Concordant Uncertain
0.4831 -0.0338 0.0462 200.0000 0.0000
200.0000 39800.0000 19228.0000 0.0000
That S.D. confuses me!!
It is obviously not the standard deviation of x or y.. but there is only one
realization of the c-index or Dxy for this sample dataset, where does the
variation come from..?? if I use the conventional formula for calculating
the standard deviation of proportions: sqrt((C Index)*(1-C Index)/n), I get
0.0353 instead of 0.0462..
Any advice is appreciated.
Vikki
--
View this message in context:
http://r.789695.n4.nabble.com/which-does-the-S-D-returned-by-Hmisc-rcorr-cens-measure-tp3329609p3329609.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
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.
