wilcox_R: What the package does (short line)

ecor <-
function(x,y,pcor=FALSE,regfun=tsreg,corfun=pbcor,outkeep=FALSE,outfun=outmgvf){
#
# Estimate the explanatory correlation between x and y
#
# It is assumed that x is a vector or a matrix having one column only
xx<-elimna(cbind(x,y)) # Remove rows with missing values
x<-xx[,1]
y<-xx[,2]
x<-as.matrix(x)
if(ncol(x) > 1)stop("x must be a vector or matrix with one column")
flag<-rep(T,nrow(x))
if(!outkeep){
temp<-outfun(cbind(x,y))$out.id
flag[temp]<-F
}
coef<-regfun(x,y)$coef
ip<-ncol(x)+1
yhat<-x %*% coef[2:ip] + coef[1]
if(pcor)epow2<-cor(yhat[flag],y[flag])^2
if(!pcor)epow2<-corfun(yhat[flag],y[flag])$cor^2
ecor<-sqrt(epow2)*sign(coef[2])
ecor
}