wilcox_R: What the package does (short line)

reg2g.p2plot <-
function(x1,y1,x2,y2,xout=FALSE,outfun=out,xlab="Var 1",ylab="Var 2",zlab="Var 3",regfun=tsreg,COLOR=TRUE,STAND=TRUE,
tick.marks=TRUE,type="p",pr=TRUE,...){
#
# Create a 3D plot of points and plot regression surface for two groups.
#
#  Assumes that the package scatterplot3d has been installed.
#  If not, use the command install.packages("scatterplot3d")
#  assuming you are connected to the web.
#
# The regression method used is specified with the argument
#  regfun.
#
#  type="p", points will be plotted. Use type="n" to get only regression planes plotted
#
x1=as.matrix(x1)
x2=as.matrix(x2)
if(ncol(x1)!=2)stop("Argument x1 must be stored in a matrix with 2 columns.")
if(ncol(x2)!=2)stop("Argument x2 must be stored in a matrix with 2 columns.")
xy1<-elimna(cbind(x1,y1))
xy2<-elimna(cbind(x2,y2))
if(xout){
if(!STAND)flag1=outfun(xy1[,1:2],plotit=FALSE,...)$keep
if(STAND)flag1=outpro(xy1[,1:2],plotit=FALSE,STAND=TRUE,...)$keep
if(!STAND)flag2=outfun(xy2[,1:2],plotit=FALSE,...)$keep
if(STAND)flag2=outpro(xy2[,1:2],plotit=FALSE,STAND=TRUE,...)$keep
xy1=xy1[flag1,]
xy2=xy2[flag2,]
}
x1=xy1[,1:2]
x2=xy2[,1:2]
y1=xy1[,3]
y2=xy2[,3]
library(scatterplot3d)
temp<-scatterplot3d(rbind(xy1,xy2),xlab=xlab,ylab=ylab,zlab=zlab,tick.marks=tick.marks,type=type)
vals1<-regfun(x1,y1,...)$coef
vals2<-regfun(x2,y2,...)$coef
if(COLOR){
if(pr)print("First group is blue")
temp$plane(vals1,col="blue")
temp$plane(vals2,col="red")
}
if(!COLOR){
temp$plane(vals1)
temp$plane(vals2)
}
list(coef.group.1=vals1,coef.group.2=vals2)
}