# R code for chapter 52 Multiway tables and crosstabs
# Book details:
# Health Science Statistics using R and R Commander
# by Robin Beaumont
# Paperback - ISBN 9781907904318
# http://www.amazon.co.uk/Health-Science-Statistics-using-Commander/dp/190790431X
# or direct from publisher at: 
# http://www.scionpublishing.com/
# book website: http://www.robin-beaumont.co.uk/rbook
###########################################################
#
mydataframe <-NULL
mydataframe <- read.table("http://www.robin-beaumont.co.uk/virtualclassroom/book2data/crosstabs1.dat",header=T)
str(mydataframe)
## mean values of each result:
tapply(mydataframe$result,  mydataframe [c('sex','illness')],mean) 
## by sex of patient and type of interviewer
tapply(mydataframe$result,  mydataframe [c('sex','illness','grouping')],mean) 
# now for the counts instead
tapply(mydataframe$result,  mydataframe [c('sex','illness','grouping')],  length ) 

# section 52.1 SPSS style crosstabs
install.packages("gmodels", dependencies=TRUE)
library(gmodels) 

CrossTable(mydataframe$illness, mydataframe$grouping, format="SPSS")

# section 52.2 Mosaic plots for multiway tables
install.packages("vcd", dependencies=TRUE) 
library(vcd)

mosaic(~ grouping +illness + sex, data = mydataframe,
  main = "Proportions by group for illness & sex", shade = TRUE, legend = TRUE)
   
 mosaic(~   sex +illness, data = mydataframe,
  main = "Proportions by group for illness & sex", shade = TRUE, legend = TRUE,
   residuals_type = "pearson", gp = shading_Friendly)