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", 
"hochberg", "bonferroni", "BH", "BY", "fdr"), group=TRUE, main = NULL)

Arguments

y Answer of the experimental unit
trt 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

Details

For equal or different repetition. p.adj = "holm", "hochberg", "bonferroni", "BH", "BY", "fdr". see p.adjust() p-adj ="none" is t-student. p-adj ="hommel" is not applied in this test.

Value

y Numeric
trt alfanumeric
DFerror Numeric
MSerror Numeric
alpha Numeric
p.adj text, see p.adjust
group Logic
main Numeric

Author(s)

Felipe de Mendiburu

References

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

See Also

HSD.test, waller.test, bar.err, bar.group

Examples

library(agricolae)
data(sweetpotato)
attach(sweetpotato)
model<-aov(yield~virus)
df<-df.residual(model)
MSerror<-deviance(model)/df
comparison <- LSD.test(yield,virus,df,MSerror, p.adj="bonferroni", group=FALSE,
main="Yield of sweetpotato\ndealt with different virus")
detach(sweetpotato)
#stargraph
bar.err(comparison,std=TRUE,ylim=c(0,45),density=4,border="blue")
#endgraph


[Package agricolae version 1.0-6 Index]