LSD.test {agricolae} R Documentation

## Multiple comparisons, "Least significant difference" and Adjust P-values

### Description

Multiple comparisons of treatments by means of LSD and a grouping of treatments. The level by alpha default is 0.05. Returns p-values adjusted using one of several methods

### Usage

LSD.test(y, trt, DFerror, MSerror, alpha = 0.05, p.adj=c("none","holm","hommel",
"hochberg", "bonferroni", "BH", "BY", "fdr"), 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 Degrees of freedom of the experimental error MSerror Means square error of the experimental alpha Level of risk for the test p.adj Method for adjusting p values (see p.adjust) group TRUE or FALSE main title of the study console logical, print output

### Details

For equal or different repetition.

It is necessary first makes a analysis of variance.
if model=y, then to apply the instruction:
LSD.test(model, "trt", alpha = 0.05, p.adj=c("none","holm","hommel", "hochberg", "bonferroni", "BH", "BY", "fdr"), group=TRUE, main = NULL,console=FALSE)
where the model class is aov or lm.

### 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

Steel, R.; Torri,J; Dickey, D.(1997) Principles and Procedures of Statistics A Biometrical Approach. pp178.

BIB.test, DAU.test, duncan.test, durbin.test, friedman, HSD.test, kruskal, 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)
#stargraph
# Variation range: max and min
plot(out)
#endgraph
# Old version LSD.test()
df<-df.residual(model)
MSerror<-deviance(model)/df
out <- with(sweetpotato,LSD.test(yield,virus,df,MSerror))
#stargraph
# Variation interquartil range: Q75 and Q25
plot(out,variation="IQR")
#endgraph