Correction:

In MSE

modmat <- model.matrix(as.formula(formula), data = d)

doesn't need as.formula, it should be

modmat <- model.matrix(formula, data = d)


Sorry,

rui Barradas

Às 09:59 de 22/03/20, Rui Barradas escreveu:
Hello,

1. There is no need to install package 'boot', it's a base package.
2. The question.

The problem is that FastTau returns an object of class "list" and there is no 'predict' method for lists, you will have to define your own.
This is easy, it's just a matrix multiply.
And you are not calling FastTau correctly, see the function documentation and the new MSE function below.



MSE <- function(data, indices, formula){
   predfun <- function(object, model){
     beta <- object[["beta"]]
     as.vector(model %*% beta)
   }
   d <- data[indices, ] # allows boot to select sample
   modmat <- model.matrix(as.formula(formula), data = d)
   fit <- FastTau(x = modmat, y = d[["y_obs"]])
   ypred <- predfun(fit, modmat)
   mean((d[["y_obs"]]-ypred)^2)
}

# Make the results reproducible
set.seed(1234)
# bootstrapping with 10 replications
results <- boot(data = df, statistic = MSE,
                 R = 10, formula = ~b+z+a)

type <- c("norm","basic", "stud", "perc", "bca")
boot.ci(results, type = type[-5])


Hope this helps,

Rui Barradas

Às 23:14 de 21/03/20, varin sacha via R-help escreveu:
Dear R-helpers,

Another problem with FastTau function from the RobPer packages. Any solution to solve my problem would be highly appreciated.


# # # # # # # # # # # # # # # # # # # # # # # #
install.packages( "boot",dependencies=TRUE )
install.packages( "RobPer",dependencies=TRUE  )

library(boot)
library(RobPer)

n<-200
b<-runif(n, 0, 5)
z <- rnorm(n, 2, 3)
a <- runif(n, 0, 5)

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) )
df<-data.frame(b,z,a,y_obs)

  # function to obtain MSE
  MSE <- function(data, indices, formula){
     d <- data[indices, ] # allows boot to select sample
     fit <- FastTau(formula, data = d)
     ypred <- predict(fit)
    mean((d[["y_obs"]]-ypred)^2)
  }
# Make the results reproducible
  set.seed(1234)
  # bootstrapping with 600 replications
  results <- boot(data = df, statistic = MSE,
                   R = 600, formula = model.matrix(~b+z+a))
str(results)

boot.ci(results, type="bca" )
# # # # # # # # # # # # # # # # # # # # # # # # #

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______________________________________________
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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.

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