if(!requireNamespace('lattice', quietly = TRUE)){
   install.packages('lattice', dependencies=TRUE, repos='http://cran.rstudio.com/')
}
library(lattice)

## This didn't work due to missing dependencies:
##
## if(!requireNamespace('RVAideMemoire', quietly = TRUE)){
##     install.packages('RVAideMemoire', dependencies=TRUE, repos='http://cran.rstudio.com/')
## }
## require('RVAideMemoire')
##
## Download the source code and install by hand:
##
## https://cran.r-project.org/web/packages/RVAideMemoire/index.html
##
## Source the code you will actuall use:
##
if( file.exists('~/Software/RVAideMemoire/R/mood.medtest.R') ){
    source('~/Software/RVAideMemoire/R/mood.medtest.R')
}

aphasic = c(56, 43, 30, 97, 67, 24, 76, 49, 46, 29, 46, 83, 93, 38, 25, 44, 66, 71, 54, 20, 25)
retarded = c(90, 53, 32, 44, 47, 42, 58, 16, 49, 54, 81, 59, 35, 81, 41, 24, 41, 61, 31, 20)

DF = data.frame(data=c(aphasic, retarded), group=c(rep('aphasic', length(aphasic)), rep('retarded', length(retarded))))
DF$group = as.factor(DF$group)

histogram(~ data | group, layout=c(1, 2), data=DF)

## Compare the means with a t-test:
##
res = t.test(aphasic, retarded)
print(res)

## Use a nonparametric method:
##
res = mood.medtest(data ~ group, data=DF)
print('Median Test:')
print(res)