Hi Duncan, Hi David, Many thanks, ok for the first error but David when you say "The second error is the misspelling . Remove the space". Where do I have to remove the space ?
Best, Sacha Le samedi 21 mars 2020 à 18:14:30 UTC+1, David Winsemius <dwinsem...@comcast.net> a écrit : On 3/21/20 9:35 AM, varin sacha via R-help wrote: > Dear R-experts, > > Here below my R code giving an error message that I don't understand. If > somebody can help me to fix it, it would be highly appreciated. > > # # # # # # # # # # # # # # # # # # # # # # # # > install.packages( "robustbase",dependencies=TRUE ) > install.packages( "boot",dependencies=TRUE ) > library(boot) > library(robustbase) > > n<-500 > b<-runif(n, 0, 5) > z <- rnorm(n, 2, 3) > a <- runif(n, 0, 5) > df<-data.frame(b,z,a) > > y_model<- 0.1*b - 0.5 * z - a + 10 > y_obs <- y_model +c( rnorm(n*0.9, 0, 0.1), rnorm(n*0.1, 0, 0.5) ) Two errors: First, you need to have the y_obs vector in the df dataframe if you later reference it as a column. > > # function to obtain MSE > MSE <- function(data, indices, formula) { > d <- data[indices, ] # allows boot to select sample > fit <- lmrob(formula, data = d) > ypred <- predict(fit) > mean((d[["y_obs "]] - ypred)^2) The second error is the misspelling . Remove the space > } > > # Make the results reproducible > set.seed(1234) > > # bootstrapping with 500 replications > results <- boot(data = df, statistic = MSE, > R = 500, formula = y_obs ~ b+z+a) > > boot.ci(results, type="bca") Now get: > boot.ci(results, type="bca") BOOTSTRAP CONFIDENCE INTERVAL CALCULATIONS Based on 500 bootstrap replicates CALL : boot.ci(boot.out = results, type = "bca") Intervals : Level BCa 95% ( 0.0237, 0.0460 ) Calculations and Intervals on Original Scale Some BCa intervals may be unstable -- David. > # # # # # # # # # # # # # # # # # # # # # # # # # > > ______________________________________________ > 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. ______________________________________________ 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.