# REGW.test: Ryan, Einot and Gabriel and Welsch multiple range test In agricolae: Statistical Procedures for Agricultural Research

## Description

Multiple range tests for all pairwise comparisons, to obtain a confident inequalities multiple range tests.

## Usage

 `1` ```REGW.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 `regw` Critical Range Table `means` Statistical summary of the study variable `comparison` Comparison between treatments `groups` Formation of treatment groups

## Author(s)

Felipe de Mendiburu

## References

Multiple comparisons theory and methods. Departament of statistics the Ohio State University. USA, 1996. Jason C. Hsu. Chapman Hall/CRC

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

## Examples

 ```1 2 3 4 5 6 7``` ```library(agricolae) data(sweetpotato) model<-aov(yield~virus,data=sweetpotato) out<- REGW.test(model,"virus", main="Yield of sweetpotato. Dealt with different virus") print(out) REGW.test(model,"virus",alpha=0.05,console=TRUE,group=FALSE) ```

### Example output

```\$statistics
MSerror Df   Mean      CV
22.48917  8 27.625 17.1666

\$parameters
test name.t ntr alpha
REGW  virus   4  0.05

\$regw
Table CriticalRange
2 3.879582      10.62212
3 4.041036      11.06417
4 4.528810      12.39967

\$means
yield      std r  Min  Max   Q25  Q50   Q75
cc 24.40000 3.609709 3 21.7 28.5 22.35 23.0 25.75
fc 12.86667 2.159475 3 10.6 14.9 11.85 13.1 14.00
ff 36.33333 7.333030 3 28.0 41.8 33.60 39.2 40.50
oo 36.90000 4.300000 3 32.1 40.4 35.15 38.2 39.30

\$comparison
NULL

\$groups
yield groups
oo 36.90000      a
ff 36.33333      a
cc 24.40000      b
fc 12.86667      c

attr(,"class")
[1] "group"

Study: model ~ "virus"

Ryan, Einot and Gabriel and Welsch multiple range test
for yield

Mean Square Error:  22.48917

virus,  means

yield      std r  Min  Max
cc 24.40000 3.609709 3 21.7 28.5
fc 12.86667 2.159475 3 10.6 14.9
ff 36.33333 7.333030 3 28.0 41.8
oo 36.90000 4.300000 3 32.1 40.4

Comparison between treatments means

difference pvalue signif.         LCL         UCL
cc - fc  11.5333333 0.0350       *   0.9112173  22.1554494
cc - ff -11.9333333 0.0360       * -22.9975029  -0.8691637
cc - oo -12.5000000 0.0482       * -24.8996698  -0.1003302
fc - ff -23.4666667 0.0006     *** -34.0887827 -12.8445506
fc - oo -24.0333333 0.0007     *** -35.0975029 -12.9691637
ff - oo  -0.5666667 0.9873         -11.1887827  10.0554494
```

agricolae documentation built on Sept. 13, 2017, 1:03 a.m.