R/qsmcobs.R

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

qsmcobs <-
function(x,y,qval=.5,xlab="X",ylab="Y",FIT=TRUE,pc=".",plotit=TRUE,
xout=FALSE,outfun=out,q=NULL,lambda=0,...){
#
# Plots smooths of quantile regression lines using R package cobs
#
# qval is the quantile
#  qsmcobs(x,y,qval=c(.2,.5,.8)) will plot three smooths corresponding to
#  the .2, .5 and .8 quantile regression lines.
#
# FIT=T, uses the values returned by predict
# FIT=F, determines predicted Y for each X and plots the results
library(cobs)
if(!is.null(q))qval=q
x=as.matrix(x)
if(xout){
flag<-outfun(x,...)$keep
x<-x[flag,]
y<-y[flag]
}
yhat=NULL
res=NULL
if(plotit)plot(x,y,xlab=xlab,ylab=ylab,pch=pc)
if(FIT){
for(j in 1:length(qval)){
if(plotit)lines(predict(cobs(x,y,tau=qval[j],lambda=lambda,print.mesg=FALSE,print.warn=FALSE)))
}}
if(!FIT){
for(j in 1:length(qval)){
temp=cobs(x,y,tau=qval[j],print.mesg=FALSE,print.warn=FALSE,lambda=lambda)
xord=order(x)
if(plotit)lines(x[xord],temp$fitted[xord])
}
if(length(qval)==1){
yhat=temp$fitted
#res=y-yhat
  # yhat is only for the unique x values. If x has,say,
#  three tied values = 6, then
#  yhat contains only one predicted value for x=6, not three yhat values
#  all equal to the predicted value at x=6 
}
}
list(yhat=yhat)
}