R/resdepth.sub.R

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

resdepth.sub <-
function(x,res)
{
##########################################################################
# This function computes the regression depth of a regression line based
# on its residuals. The fit could be, for example, a nonparmatric
# regression or smooth.
#
# The algorithm is based on a simple modification of
#
#           Rousseeuw, P.J. and Hubert, M. (1996),
#           Regression Depth, Technical report, University of Antwerp
#
##########################################################################
        if(!is.vector(x)) stop("x should be vectors")
        n <- length(x)
        if(n < 2)
                stop("you need at least two observations")
flag=is.na(res)
x=x[!flag]
res[!flag]
xord=order(x)
x=x[xord]
res=res[xord]
        posres <- res >= 0
        negres <- res <= 0
        lplus <- cumsum(posres)
        rplus <- lplus[n] - lplus
        lmin <- cumsum(negres)
        rmin <- lmin[n] - lmin
        depth <- pmin(lplus + rmin, rplus + lmin)
        min(depth)
}