diff --git a/R/legTools.R b/R/legTools.R
index f062b1ccfbc8bc65fdea38a960de9382b9de6c0e..963ddcc7185899a55a9d08ef76291ceefa5010c2 100644
--- a/R/legTools.R
+++ b/R/legTools.R
@@ -528,48 +528,105 @@ NULL
#'
#' library(lattice)
#' library(latticeExtra)
-#'
+#'
#' data(kornYield)
#' str(kornYield)
-#'
+#'
#' xyplot(yield~N|P, groups=K,
#' data=kornYield, type=c("p", "a"),
#' ylab=expression(Yield~(ton~ha^{-1})),
#' xlab="Nutrient level")
-#'
+#'
#' xyplot(yield~N, groups=interaction(P, K),
#' data=kornYield, type=c("p", "a"),
#' auto.key=list(columns=2),
#' ylab=expression(Yield~(ton~ha^{-1})),
#' xlab="Nutrient level")
-#'
+#'
#' m0 <- lm(yield~block+(N+P+K)^3, data=kornYield)
#' par(mfrow=c(2,2)); plot(m0); layout(1)
#' anova(m0)
-#'
+#'
#' m1 <- update(m0, .~block+N+K)
#' par(mfrow=c(2,2)); plot(m1); layout(1)
-#'
+#'
#' anova(m0, m1)
#' anova(m1)
-#'
+#'
#' summary(m1)
-#'
+#'
#' pred <- expand.grid(block="1",
#' N=seq(-1, 1, by=0.1),
#' K=seq(-1, 1, by=0.1))
#' pred$mu <- predict(m1, newdata=pred)
-#'
+#'
#' wireframe(mu~N+K, data=pred,
#' scales=list(arrows=FALSE),
#' zlab=list(expression(Yield~(ton~ha^{-1})), rot=90),
#' drape=TRUE, cuts=20,
#' col.regions=colorRampPalette(
#' color=brewer.pal(n=11, name="Spectral"))(21))
-#'
+#'
#' levelplot(mu~N+K, data=pred, aspect=1,
#' main=expression(Yield~(ton~ha^{-1})),
#' col.regions=colorRampPalette(
#' color=brewer.pal(n=11, name="Spectral")))
#'
NULL
+
+#' @name vinasseFert
+#'
+#' @title Fertilization with vinasse and mineral
+#'
+#' @description These data are from an \eqn{2^2} factorial experiment
+#' studing the effect of fertilizaton with vinasse (organic font)
+#' and complete mineral fertilization.
+#'
+#' \itemize{
+#' \item \code{block} a factor with 4 levels.
+#' \item \code{mineral} low (-1) and high (+1) levels of mineral
+#' fertilization.
+#' \item \code{vinasse} low (-1) and high (+1) levels of fetilization
+#' with vinasse.
+#' \item \code{y} some response variable. The text book doesn't give
+#' any information.
+#' }
+#'
+#' @docType data
+#'
+#' @keywords datasets
+#'
+#' @usage data(vinasseFert)
+#'
+#' @format a \code{data.frame} with 16 records and 4 variables.
+#'
+#' @source Frederico, P. (2009). Curso de Estatística Experimental (15th
+#' ed.). Piracicaba, São Paulo: FEALQ. (page 119)
+#'
+#' @examples
+#'
+#' library(lattice)
+#' library(latticeExtra)
+#'
+#' data(vinasseFert)
+#' str(vinasseFert)
+#'
+#' xyplot(y~vinasse, groups=mineral,
+#' auto.key=list(title="Mineral", columns=2),
+#' data=vinasseFert, type=c("p", "a"),
+#' ylab="y",
+#' xlab="Vinasse level")
+#'
+#' m0 <- lm(y~block+(vinasse+mineral)^2, data=vinasseFert)
+#' par(mfrow=c(2,2)); plot(m0); layout(1)
+#' anova(m0)
+#'
+#' m1 <- update(m0, .~block+vinasse)
+#' par(mfrow=c(2,2)); plot(m1); layout(1)
+#'
+#' anova(m0, m1)
+#' anova(m1)
+#'
+#' summary(m1)
+#'
+NULL
diff --git a/data-raw/vinasseFert.R b/data-raw/vinasseFert.R
new file mode 100644
index 0000000000000000000000000000000000000000..be78f45e285e2a4c57869c6660cded7523392a86
--- /dev/null
+++ b/data-raw/vinasseFert.R
@@ -0,0 +1,45 @@
+##----------------------------------------------------------------------
+## Data generation.
+
+vinasseFert <- expand.grid(block=gl(4, 1), mineral=c(-1, 1),
+ vinasse=c(-1, 1), KEEP.OUT.ATTRS=FALSE)
+
+vinasseFert$y <- c(0.020, 0.630, 0.110, 0.115, 0.020, 2.005, 0.700,
+ 1.120, 3.040, 4.760, 5.860, 5.520, 5.150, 4.770,
+ 3.960, 5.230)
+
+str(vinasseFert)
+
+save(vinasseFert, file="../data/vinasseFert.RData")
+
+##----------------------------------------------------------------------
+## Examples.
+
+library(lattice)
+library(latticeExtra)
+
+data(vinasseFert)
+str(vinasseFert)
+
+xyplot(y~vinasse, groups=mineral,
+ auto.key=list(title="Mineral", columns=2),
+ data=vinasseFert, type=c("p", "a"),
+ ylab="y",
+ xlab="Vinasse level")
+
+m0 <- lm(y~block+(vinasse+mineral)^2, data=vinasseFert)
+par(mfrow=c(2,2)); plot(m0); layout(1)
+anova(m0)
+
+m1 <- update(m0, .~block+vinasse)
+par(mfrow=c(2,2)); plot(m1); layout(1)
+
+anova(m0, m1)
+anova(m1)
+
+summary(m1)
+
+rm(list=ls())
+load("../data/vinasseFert.RData")
+ls()
+str(vinasseFert)
diff --git a/data/vinasseFert.RData b/data/vinasseFert.RData
new file mode 100644
index 0000000000000000000000000000000000000000..68936a5086a615fd434fb664c2fe78942a8ab486
Binary files /dev/null and b/data/vinasseFert.RData differ
diff --git a/man/vinasseFert.Rd b/man/vinasseFert.Rd
new file mode 100644
index 0000000000000000000000000000000000000000..981cc37232a997c214223a387b0cb266ea5386a4
--- /dev/null
+++ b/man/vinasseFert.Rd
@@ -0,0 +1,56 @@
+% Generated by roxygen2 (4.1.1): do not edit by hand
+% Please edit documentation in R/legTools.R
+\docType{data}
+\name{vinasseFert}
+\alias{vinasseFert}
+\title{Fertilization with vinasse and mineral}
+\format{a \code{data.frame} with 16 records and 4 variables.}
+\source{
+Frederico, P. (2009). Curso de Estatística Experimental (15th
+ ed.). Piracicaba, São Paulo: FEALQ. (page 119)
+}
+\usage{
+data(vinasseFert)
+}
+\description{
+These data are from an \eqn{2^2} factorial experiment
+ studing the effect of fertilizaton with vinasse (organic font)
+ and complete mineral fertilization.
+
+\itemize{
+ \item \code{block} a factor with 4 levels.
+ \item \code{mineral} low (-1) and high (+1) levels of mineral
+ fertilization.
+ \item \code{vinasse} low (-1) and high (+1) levels of fetilization
+ with vinasse.
+ \item \code{y} some response variable. The text book doesn't give
+ any information.
+}
+}
+\examples{
+library(lattice)
+library(latticeExtra)
+
+data(vinasseFert)
+str(vinasseFert)
+
+xyplot(y~vinasse, groups=mineral,
+ auto.key=list(title="Mineral", columns=2),
+ data=vinasseFert, type=c("p", "a"),
+ ylab="y",
+ xlab="Vinasse level")
+
+m0 <- lm(y~block+(vinasse+mineral)^2, data=vinasseFert)
+par(mfrow=c(2,2)); plot(m0); layout(1)
+anova(m0)
+
+m1 <- update(m0, .~block+vinasse)
+par(mfrow=c(2,2)); plot(m1); layout(1)
+
+anova(m0, m1)
+anova(m1)
+
+summary(m1)
+}
+\keyword{datasets}
+