#' @title Example 7.2 from Generalized Linear Mixed Models: Modern Concepts, Methods and Applications by Walter W. Stroup (p-219)
#' @name Exam7.2
#' @docType data
#' @keywords datasets
#' @description Exam7.2 explains multifactor models with some factors qualitative and some quantitative(Equal slopes ANCOVA)
#' @author \enumerate{
#' \item Muhammad Yaseen (\email{myaseen208@@gmail.com})
#' \item Adeela Munawar (\email{adeela.uaf@@gmail.com})
#' }
#' @references \enumerate{
#' \item Stroup, W. W. (2012).
#' \emph{Generalized Linear Mixed Models: Modern Concepts, Methods and Applications}.
#' CRC Press.
#' }
#' @seealso
#' \code{\link{DataSet7.2}}
#'
#' @import lsmeans car ggplot2
#'
#' @examples
library(lsmeans)
library(car)
library(ggplot2)
data(DataSet7.2)
DataSet7.2$trt <- factor( x = DataSet7.2$trt )
##----ANCOVA(Equal slope Model)
Exam7.2fm1 <-
aov(
formula = y ~ trt*x
, data = DataSet7.2
)
car::Anova( mod = Exam7.2fm1 , type="III")
##---ANCOVA(without interaction because of non significant slope effect)
Exam7.2fm2 <-
aov(
formula = y ~ trt + x
, data = DataSet7.2
)
car::Anova(mod = Exam7.2fm2 , type="III")
##---Ls means for 2nd model
( Lsm7.2 <-
lsmeans::lsmeans(
object = Exam7.2fm2
, specs = ~trt
# , ...
)
)
##---Anova without covariate
Exam7.2fm3 <-
aov(
formula = y ~ trt
, data = DataSet7.2
)
car::Anova( mod = Exam7.2fm3,type="III")
##---Ls means for 3rd model
( Lsm7.2 <-
lsmeans::lsmeans(
object = Exam7.2fm3
, specs = ~trt
# , ...
)
)
##---Box Plot of Covariate by treatment
Plot <-
ggplot(
data = DataSet7.2
, mapping = aes(x= factor(trt), y=x)
) +
geom_boxplot(width=0.5) +
coord_flip() +
geom_point() +
stat_summary(
fun.y = "mean"
, geom = "point"
, shape = 23
, size = 2
, fill = "red"
) +
theme_bw() +
ggtitle("Covariate by treatment Box Plot") +
xlab("Treatment")
print(Plot)
NULL
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.