Dear R-Experts,
I am trying to get the bootstrapped confidence intervals of R-squared
(Nagelkerke) for an ordinal logistic regression. Something is going wrong at
the end of my script. Many thanks for your help.
Here is my reproducible example.
install.packages("rms")
library(rms)
x=c(1,2,3,2,3,1,2,3,3,3,2,2,1,2,1,2,3,2,1,2)
y=c("math","eco","eco","lit","lit","eco","eco","math","math","lit","lit","math","eco","eco","math","lit","lit","math","eco","math")
Dataset<-data.frame(x,y)
h <- orm(x ~ y)
h
# Bootstrap 95% CI for R-Squared
library(boot)
# function to obtain R-Squared from the data
rsq <- function(formula, data, indices) {
d <- data[indices,] # allows boot to select sample
fit <- orm(x ~ y, data=data[indices,])
return((fit)$r.square)
}
# bootstrapping with 1000 replications
results <- boot(data=Dataset, statistic=rsq, R=1000, formula=x ~ y)
# view results
results
plot(results)
# get 95% confidence interval
boot.ci(results, type="bca")
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
