durbin.test: Durbin test and multiple comparison of treatments
In agricolae: Statistical Procedures for Agricultural Research

durbin.test

R Documentation

Durbin test and multiple comparison of treatments

Description

A multiple comparison of the Durbin test for the balanced incomplete blocks for sensorial or categorical evaluation. It forms groups according to the demanded ones for level of significance (alpha); by default, 0.05.

Usage

durbin.test(judge, trt, evaluation, alpha = 0.05, group =TRUE, 
main = NULL, console=FALSE)

Arguments

`judge`	Identification of the judge in the evaluation
`trt`	Treatments
`evaluation`	variable
`alpha`	level of significant
`group`	TRUE or FALSE
`main`	Title
`console`	logical, print output

Details

The post hoc test is using the criterium Fisher's least significant difference.

Value

`statistics`	Statistics of the model
`parameters`	Design parameters
`means`	Statistical summary of the study variable
`rank`	rank table of the study variable
`comparison`	Comparison between treatments
`groups`	Formation of treatment groups

Author(s)

Felipe de Mendiburu

References

Practical Nonparametrics Statistics. W.J. Conover, 1999 Nonparametric Statistical Methods. Myles Hollander and Douglas A. Wofe, 1999

Examples

library(agricolae)
# Example 1. Conover, pag 391
person<-gl(7,3)
variety<-c(1,2,4,2,3,5,3,4,6,4,5,7,1,5,6,2,6,7,1,3,7)
preference<-c(2,3,1,3,1,2,2,1,3,1,2,3,3,1,2,3,1,2,3,1,2)
out<-durbin.test(person,variety,preference,group=TRUE,console=TRUE,
main="Seven varieties of ice cream manufacturer")
#startgraph
bar.group(out$groups,horiz=TRUE,xlim=c(0,10),density=4,las=1)
#endgraph
# Example 2. Myles Hollander, pag 311
# Source: W. Moore and C.I. Bliss. 1942
day<-gl(7,3)
chemical<-c("A","B","D","A","C","E","C","D","G","A","F","G","B","C","F",
 "B","E","G","D","E","F")
toxic<-c(0.465,0.343,0.396,0.602,0.873,0.634,0.875,0.325,0.330,0.423,0.987,
0.426,0.652,1.142,0.989,0.536,0.409,0.309,0.609,0.417,0.931)
out<-durbin.test(day,chemical,toxic,group=TRUE,console=TRUE,
main="Logarithm of Toxic Dosages")
plot(out)

agricolae documentation built on Oct. 23, 2023, 1:06 a.m.