R/qhomtsub.R

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

qhomtsub <-
function(isub,x,y,qval){
#
#  Perform quantile 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))
temp<-qplotreg(xmat,y[isub],qval=qval,plotit=FALSE)
regboot<-temp[1,2]-temp[2,2]
regboot
}