diff --git a/NAMESPACE b/NAMESPACE
index ced143cedaa370ee87b2c33d21141f99d89862a8..776c53ed63afff0ae1e87245f60010a574a16a6b 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,6 +1,7 @@
# Generated by roxygen2 (4.1.1): do not edit by hand
export(biasBox)
+export(loessGui)
export(polyGui)
export(subsetDropAll)
export(twoStripCombined)
diff --git a/R/loessGui.R b/R/loessGui.R
new file mode 100644
index 0000000000000000000000000000000000000000..2ec9d051e374c38de1a06045f5770021eda15804
--- /dev/null
+++ b/R/loessGui.R
@@ -0,0 +1,218 @@
+#' @title Loess regression GUI
+#'
+#' @name loessGui
+#'
+#' @description This function opens an interface to control the settings
+#' of a loess regression:
+#' \itemize{
+#' \item degree choose the local polynomial degree with a radio
+#' selector;
+#' \item span set the span value that controls the degree of
+#' smoothing;
+#' \item center move the x value to be predicted;
+#' }
+#'
+#' The elements of the interface change a plot that shows the observed
+#' values and the corresponding fitted curve superimposed with
+#' confidence bands (for the fitted values). It assumes that
+#' \code{gWidgets} and \code{gWidgetstcltk} packages are available.
+#'
+#' @param x,y independent and dependent (numeric) regression variables.
+#'
+#' @param data an optional \code{data.frame}.
+#'
+#' @param er stands for extend range. It is used to extend the plotting
+#' range by a fraction on both sides and directions. Default is
+#' 0.05. See \link[grDevices]{extendrange}.
+#'
+#' @return None is returned by the function, only a GUI is opened.
+#'
+#' @import gWidgets gWidgetstcltk
+#'
+#' @author Walmes Zeviani, \email{walmes@@ufpr.br}
+#'
+#' @export
+#' @examples
+#' \donttest{
+#'
+#' library(gWidgets)
+#' library(gWidgetstcltk)
+#'
+#' loessGui(x=area, y=peri, data=rock, er=0.3)
+#' loessGui(x=speed, y=dist, data=cars, er=0.3)
+#' loessGui(x=eruptions, y=waiting, data=faithful, er=0.3)
+#'
+#' }
+loessGui <- function(x, y, data, er=0.05){
+ ##
+ ##-------------------------------------------
+ ## Loading the required packages.
+ ##
+ if (!requireNamespace("gWidgets", quietly=TRUE)){
+ stop("`gWidgets` needed for this function to work. Please install it.",
+ call.=FALSE)
+ }
+ if (!requireNamespace("gWidgetstcltk", quietly=TRUE)){
+ stop("`gWidgetstcltk` needed for this function to work. Please install it.",
+ call.=FALSE)
+ }
+ options(guiToolkit="tcltk")
+ ##
+ ##-------------------------------------------
+ ## Auxiliary variables not controled by the GUI.
+ ##
+ xlab <- deparse(substitute(x))
+ ylab <- deparse(substitute(y))
+ if(!missing(data)){
+ da <- eval(data, envir=parent.frame())
+ x <- da[, deparse(substitute(x))]
+ y <- da[, deparse(substitute(y))]
+ }
+ xl <- range(x)
+ nx <- length(x)
+ erx <- extendrange(xl, f=er)
+ ery <- extendrange(y, f=er)
+ newdata <- data.frame(x=seq(erx[1], erx[2], length.out=200))
+ ##
+ ##-------------------------------------------
+ ## Functions to annotate in the plot upper margin.
+ ##
+ annotations <- function(m0, y){
+ mtext(side=3, adj=0, line=1.5,
+ text=sprintf("H trace: %0.2f", m0$trace.hat))
+ mtext(side=3, adj=0, line=0.5,
+ text=sprintf("Equivalent num. param.: %0.2f", m0$enp))
+ r2 <- 100*cor(fitted(m0), y)^2
+ mtext(side=3, adj=1, line=1.5,
+ text=sprintf("R^2: %0.2f", r2))
+ }
+ ##
+ ##-------------------------------------------
+ ## Functions to adjust 0 order, 1 and 2 local polynomial regression
+ ## model.
+ ##
+ f0 <- function(w, xl){
+ y.pred <- sum(w*y)/sum(w)
+ segments(xl[1], y.pred, xl[2], y.pred, col=2)
+ }
+ f1 <- function(w, xl){
+ m <- lm(y~poly(x, degree=1), weights=w)
+ y.pred <- predict(m, newdata=list(x=xl))
+ segments(xl[1], y.pred[1], xl[2], y.pred[2], col=2)
+ }
+ f2 <- function(w, xl){
+ m <- lm(y~poly(x, degree=2), weights=w)
+ x.pred <- seq(xl[1], xl[2], length.out=20)
+ y.pred <- predict(m, newdata=list(x=x.pred))
+ lines(x.pred, y.pred, col=2)
+ }
+ ##
+ ##-------------------------------------------
+ ## Reactive function.
+ ##
+ draw.loess <- function(...){
+ ##
+ ##-------------------------------------------
+ ## Fit loess regression.
+ ##
+ m0 <- loess(formula=y~x,
+ span=svalue(SPAN),
+ degree=as.integer(svalue(DEGREE)),
+ family="gaussian")
+ ##
+ ##-------------------------------------------
+ ## Predicted values with confidence bands.
+ ##
+ pred <- predict(m0, newdata=newdata, se=TRUE)
+ pred$me <- pred$se.fit*1.96
+ pred$ci <- sweep(x=cbind(fit=0, lwr=-pred$me, upr=pred$me),
+ MARGIN=1, STATS=pred$fit, FUN="+")
+ ##
+ ##-------------------------------------------
+ ## Weights to be used in local polynomial.
+ ##
+ x0 <- svalue(XCENTER)
+ sp <- svalue(SPAN)
+ a <- abs(x-x0)
+ if (sp < 1){
+ q <- as.integer(sp*nx)
+ d <- sort(a)[q]
+ } else {
+ q <- nx
+ d <- max(abs(a))*sqrt(sp)
+ }
+ s <- a <= d
+ w <- rep(0, nx)
+ w[s] <- (1-(a[s]/d)^3)^3
+ ##
+ ##-------------------------------------------
+ ## Scatter plot, point size proportional to weight.
+ ##
+ i <- as.integer(s)
+ plot(x, y,
+ pch=2*(!s)+1, cex=i*3*w+1,
+ xlim=erx, ylim=ery)
+ ##
+ ##-------------------------------------------
+ ## Local polynomial.
+ ##
+ xl[1] <- ifelse(x0 - d>xl[1], x0-d, xl[1])
+ xl[2] <- ifelse(x0 + d<xl[2], x0+d, xl[2])
+ matlines(x=newdata$x, y=pred$ci, lty=c(1,2,2), col=1)
+ abline(v=c(x0, xl), lty=c(2,3,3))
+ annotations(m0, y)
+ mtext(side=3, adj=1, line=0.5,
+ text=sprintf("Number of obs. used/total: %i/%i",
+ sum(s), nx))
+ ## NOTE: usar action aqui!
+ ## xl <- c(min(c(xl[1], x0)), max(c(x0, xl[2])))
+ do.call(what=paste0("f", svalue(DEGREE)),
+ args=list(w=w, xl=xl))
+ }
+ ##
+ ##-------------------------------------------
+ ## Building the GUI.
+ ##
+ WDW <- gwindow(title="LOESS regression", visible=FALSE)
+ GG <- ggroup(container=WDW, expand=TRUE, horizontal=FALSE)
+ GF_DG <- gframe(text="Local polynomial degree:", container=GG)
+ DEGREE <- gradio(items=0:2, selected=2L, horizontal=TRUE,
+ handler=draw.loess,
+ container=GF_DG)
+ GF_XC <- gframe(text="Predicted point:", expand=TRUE, container=GG)
+ XCENTER <- gslider(from=erx[1], to=erx[2],
+ value=mean(erx),
+ length.out=51,
+ handler=draw.loess,
+ expand=TRUE,
+ container=GF_XC)
+ XCLABEL <- glabel(text=sprintf("%0.2f", svalue(XCENTER)),
+ container=GF_XC)
+ addHandlerChanged(XCENTER,
+ action=XCLABEL,
+ handler=function(h, ...){
+ svalue(h$action) <-
+ sprintf("%0.2f", svalue(h$obj))
+ })
+ GF_SP <- gframe(text="Span:", expand=TRUE,container=GG)
+ SPAN <- gslider(from=0, to=1.5,
+ value=0.75, by=0.05,
+ handler=draw.loess,
+ expand=TRUE,
+ container=GF_SP)
+ SPLABEL <- glabel(text=sprintf("%0.2f", svalue(SPAN)),
+ container=GF_SP)
+ addHandlerChanged(SPAN,
+ action=SPLABEL,
+ handler=function(h, ...){
+ svalue(h$action) <-
+ sprintf("%0.2f", svalue(h$obj))
+ })
+ ##-------------------------------------------
+ ## Initializing.
+ svalue(SPAN) <- 0.75
+ svalue(DEGREE) <- 1L
+ svalue(XCENTER) <- mean(erx)
+ do.call(what=draw.loess, args=list(NA))
+ visible(WDW) <- TRUE
+}
diff --git a/man/loessGui.Rd b/man/loessGui.Rd
new file mode 100644
index 0000000000000000000000000000000000000000..6c5ad1404e9efeed995a7de4eb7c4a52d76d0162
--- /dev/null
+++ b/man/loessGui.Rd
@@ -0,0 +1,52 @@
+% Generated by roxygen2 (4.1.1): do not edit by hand
+% Please edit documentation in R/loessGui.R
+\name{loessGui}
+\alias{loessGui}
+\title{Loess regression GUI}
+\usage{
+loessGui(x, y, data, er = 0.05)
+}
+\arguments{
+\item{x,y}{independent and dependent (numeric) regression variables.}
+
+\item{data}{an optional \code{data.frame}.}
+
+\item{er}{stands for extend range. It is used to extend the plotting
+range by a fraction on both sides and directions. Default is
+0.05. See \link[grDevices]{extendrange}.}
+}
+\value{
+None is returned by the function, only a GUI is opened.
+}
+\description{
+This function opens an interface to control the settings
+of a loess regression:
+\itemize{
+ \item degree choose the local polynomial degree with a radio
+selector;
+ \item span set the span value that controls the degree of
+smoothing;
+ \item center move the x value to be predicted;
+}
+
+The elements of the interface change a plot that shows the observed
+values and the corresponding fitted curve superimposed with
+confidence bands (for the fitted values). It assumes that
+\code{gWidgets} and \code{gWidgetstcltk} packages are available.
+}
+\examples{
+\donttest{
+
+library(gWidgets)
+library(gWidgetstcltk)
+
+loessGui(x=area, y=peri, data=rock, er=0.3)
+loessGui(x=speed, y=dist, data=cars, er=0.3)
+loessGui(x=eruptions, y=waiting, data=faithful, er=0.3)
+
+}
+}
+\author{
+Walmes Zeviani, \email{walmes@ufpr.br}
+}
+