R/qindbt.sub.R

In musto101/wilcox_R: What the package does (short line)

qindbt.sub <-
function(isub,x,y,qval){
#
#  Perform regression using x[isub] to predict y[isub]
#  isub is a vector of length n,
#  a bootstrap sample from the sequence of integers
#  1, 2, 3, ..., n
#
#  This function is used by other functions when computing
#  bootstrap estimates.
#
#  regfun is some regression method already stored in R
#  It is assumed that regfun$coef contains the  intercept and slope
#  estimates produced by regfun.  The regression methods written for
#  this  book, plus regression functions in R, have this property.
#
#  x is assumed to be a matrix containing values of the predictors.
#
xmat<-matrix(x[isub,],nrow(x),ncol(x))
regboot<-NA
for(i in 1:length(qval)){
regboot[i]<-qreg(xmat,y[isub],qval[i])$coef[2]
}
regboot
}