R/loc_max.r

In npbr: Nonparametric Boundary Regression

loc_max <- function(xtab, ytab, x, h, type = "one-stage"){
  # verification
  stopifnot(type%in%c("one-stage","two-stage"))
 
  # initialisation
  nx = length(x)
  res = matrix(0,1,nx)

  for(j in 1:nx){
  ztab = ytab * as.numeric(abs(xtab-x[j])<=h)
  res[j] = max(ztab)
  }

 if(type=="two-stage"){ 
   for(j in 1:nx)
    res[j] <- dea_est(xtab, ifelse(abs(xtab-x[j])<=h, res[j], ytab), x[j], type = "dea")
  }
 return(res)
}