waller.test | R Documentation |
The Waller-Duncan k-ratio t test is performed on all main effect means in the MEANS statement. See the K-RATIO option for information on controlling details of the test.
waller.test(y, trt, DFerror, MSerror, Fc, K = 100, group=TRUE, main = NULL,
console=FALSE)
y |
model(aov or lm) or answer of the experimental unit |
trt |
Constant( only y=model) or vector treatment applied to each unit |
DFerror |
Degrees of freedom |
MSerror |
Mean Square Error |
Fc |
F Value |
K |
K-RATIO |
group |
TRUE or FALSE |
main |
Title |
console |
logical, print output |
It is necessary first makes a analysis of variance.
K-RATIO (K): value specifies the Type 1/Type 2 error seriousness ratio for
the Waller-Duncan test. Reasonable values for KRATIO are 50, 100, and 500,
which roughly correspond for the two-level case to ALPHA levels of 0.1, 0.05,
and 0.01. By default, the procedure uses the default value of 100.
if y = model, then to apply the instruction:
waller.test (model, "trt", alpha = 0.05, group = TRUE, main = NULL, console = FALSE)
where the model class is aov or lm.
statistics |
Statistics of the model |
parameters |
Design parameters |
means |
Statistical summary of the study variable |
comparison |
Comparison between treatments |
groups |
Formation of treatment groups |
Felipe de Mendiburu
Waller, R. A. and Duncan, D. B. (1969).
A Bayes Rule for the Symmetric Multiple Comparison Problem,
Journal of the American Statistical Association 64, pages 1484-1504.
Waller, R. A. and Kemp, K. E. (1976)
Computations of Bayesian t-Values for Multiple Comparisons,
Journal of Statistical Computation and Simulation, 75, pages 169-172.
Steel & Torry & Dickey. Third Edition 1997 Principles and procedures of statistics a biometrical approach
BIB.test
, DAU.test
, duncan.test
,
durbin.test
, friedman
, HSD.test
,
kruskal
, LSD.test
, Median.test
,
PBIB.test
, REGW.test
, scheffe.test
,
SNK.test
, waerden.test
, plot.group
library(agricolae)
data(sweetpotato)
model<-aov(yield~virus, data=sweetpotato)
out <- waller.test(model,"virus", group=TRUE)
#startgraph
oldpar<-par(mfrow=c(2,2))
# variation: SE is error standard
# variation: range is Max - Min
bar.err(out$means,variation="SD",horiz=TRUE,xlim=c(0,45),bar=FALSE,
col=colors()[25],space=2, main="Standard deviation",las=1)
bar.err(out$means,variation="SE",horiz=FALSE,ylim=c(0,45),bar=FALSE,
col=colors()[15],space=2,main="SE",las=1)
bar.err(out$means,variation="range",ylim=c(0,45),bar=FALSE,col="green",
space=3,main="Range = Max - Min",las=1)
bar.group(out$groups,horiz=FALSE,ylim=c(0,45),density=8,col="red",
main="Groups",las=1)
#endgraph
# Old version HSD.test()
df<-df.residual(model)
MSerror<-deviance(model)/df
Fc<-anova(model)["virus",4]
out <- with(sweetpotato,waller.test(yield, virus, df, MSerror, Fc, group=TRUE))
print(out)
par(oldpar)
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