SNK.test {agricolae} R Documentation

## Student-Newman-Keuls (SNK)

### Description

SNK is derived from Tukey, but it is less conservative (finds more differences). Tukey controls the error for all comparisons, where SNK only controls for comparisons under consideration. The level by alpha default is 0.05.

### Usage

SNK.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.

if y = model, then to apply the instruction:
SNK.test (model, "trt", alpha = 0.05, group = TRUE, main = NULL, console = FALSE)
where the model class is aov or lm.

### Value

 statistics Statistics of the model parameters Design parameters snk 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

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.

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

### Examples

library(agricolae)
data(sweetpotato)
model<-aov(yield~virus,data=sweetpotato)
out <- SNK.test(model,"virus", console=TRUE,
main="Yield of sweetpotato. Dealt with different virus")
print(SNK.test(model,"virus", group=FALSE))
# version old SNK.test()
df<-df.residual(model)
MSerror<-deviance(model)/df
out <- with(sweetpotato,SNK.test(yield,virus,df,MSerror, group=TRUE))
print(out\$groups)


[Package agricolae version 1.3-7 Index]