R: Multiple comparisons: Tukey

HSD.test {agricolae} | R Documentation

## Multiple comparisons: Tukey

### Description

It makes multiple comparisons of treatments by means of Tukey. The level by alpha default is 0.05.

### Usage

    HSD.test(y, trt, DFerror, MSerror, alpha = 0.05, group=TRUE, main = NULL,console=FALSE)

### Arguments

`y` | model(aov or lm) or answer of the experimental unit
`trt` | Constant( only y=model) or vector treatment applied to each experimental unit
`DFerror` | Degree free
`MSerror` | Mean Square Error
`alpha` | Significant level
`group` | TRUE or FALSE
`main` | Title
`console` | logical, print output

### Details

It is necessary first makes a analysis of variance.

### Value

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

### Author(s)

Felipe de Mendiburu

### References

1. Principles and procedures of statistics a biometrical approach Steel & Torry & Dickey. Third Edition 1997 2. Multiple comparisons theory and methods. Departament of statistics the Ohio State University. USA, 1996. Jason C. Hsu. Chapman Hall/CRC.

### See Also

`BIB.test`, `DAU.test`, `duncan.test`, `durbin.test`, `friedman`, `kruskal`, `LSD.test`, `Median.test`, `PBIB.test`, `REGW.test`, `scheffe.test`, `SNK.test`, `waerden.test`, `waller.test`, `plot.group`

### Examples

    library(agricolae)
    data(sweetpotato)
    model<-aov(yield~virus, data=sweetpotato)
    out <- HSD.test(model,"virus", group=TRUE,console=TRUE,
    main="Yield of sweetpotato\nDealt with different virus")
    #stargraph
    # Variation range: max and min
    plot(out)
    #endgraph
    out<-HSD.test(model,"virus", group=FALSE)
    print(out$comparison)
    # Old version HSD.test()
    df<-df.residual(model)
    MSerror<-deviance(model)/df
    with(sweetpotato,HSD.test(yield,virus,df,MSerror, group=TRUE,console=TRUE,
    main="Yield of sweetpotato. Dealt with different virus"))

[Package agricolae version 1.2-8 Index]