difference between 2 ecdfs
In article <0FF736F1E306A446A88FD41FDDDC10AF1C77B0 at BWPW05.f2.enterprise>,
<Erwann.Rogard at sanofi-aventis.com> wrote:
hi,
a) i have something like:
ecdfgrp1<-ecdf(subset(mydata,TMT_GRP==1)$Y);
ecdfgrp2<-ecdf(subset(mydata,TMT_GRP==2)$Y);
how can i plot the difference between these 2 step functions?
i could begin with ecdfrefl<-function(x){ecdfgrp2(x)-ecdfgrp1(x);} ...
what next?
#not tested ...mydata not provided ecrange<-range(mydata$Y) plot(ecdfrefl(seq(from=ecrange[1],to=ecrange[2],by=0.2))
b) if i have a vector with repeated numeric values how can i get the subset without repeated values .e.g (0,4,0,2,2) ----> (0,4,2) ?
?unique
ttt<-c(1,3,5,5,5,7) unique(ttt)
[1] 1 3 5 7
David Winsemius