[R] Arguments in functions

[Prew, Paul]

Hello,  I'm not much of a programmer, and am trying to understand the workings of the function below called "RStatFctn" within this bootstrap procedure.  

RStatFctn is defined to have two arguments: "x", intended to be a data vector; and "d" intended to be an index (or so it looks to me).
Later, "rnormdat" is created to be the data vector.   However, when RStatFctn is called within the bootstrap function, I don't see where "rnormdat" is explicitly passed to RStatFctn as the data vector "x".  And I don't see where any values are ever passed to the index variable "d", or where any index is ever referenced or used in conjunction with RStatFctn.

Any help you can offer is appreciated.

Thanks, Paul

library(boot)

RStatFctn <- function(x,d) {return(mean(x[d]))}

b.basic = matrix(data=NA, nrow=1000, ncol=2) b.normal = matrix(data=NA, nrow=1000, ncol=2) b.percent =matrix(data=NA, nrow=1000, ncol=2) b.bca =matrix(data=NA, nrow=1000, ncol=2)

for(i in 1:1000){
rnormdat = rnorm(30,0,1)
b <- boot(rnormdat, RStatFctn, R = 1000) b.ci=boot.ci(b, conf =0.95,type=c("basic","norm","perc","bca"))
b.basic[i,] = b.ci$basic[,4:5]
b.normal[i,] = b.ci$normal[,2:3]
b.percent[i,] = b.ci$percent[,4:5]
b.bca[i,] = b.ci$bca[,4:5]
} 

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