############################################################################
# NAME:  Chris Bilder                                                      #
# DATE:  9-19-05                                                           #
# PURPOSE: Do the histogram trellis plot using standardized data within    #
#          a variable specification only (not by shelf)                    #
#                                                                          #
# NOTES: 1)                                                                #
#                                                                          #
############################################################################

#R IS CASE SENSITIVE

#Read in the data
cereal<-read.table(file = "C:\\chris\\UNL\\STAT873\\Chapter 3\\cereal.txt", header=TRUE)


library(lattice)
trellis.par.set(col.whitebg()) #Set color theme for plots


#New way using the scale function.
  temp<-data.frame(sugar2 = cereal$sugar, fat2 = cereal$fat, sodium2 = cereal$sodium)
  stand.cereal<-scale(temp)
  cereal2<-data.frame(cereal, stand.cereal)
  
  sugar<-data.frame(ID = cereal2$ID, Shelf = cereal2$Shelf, value = cereal2$sugar2, variable = "Sugar")
  fat<-data.frame(ID = cereal2$ID, Shelf = cereal2$Shelf, value = cereal2$fat2, variable = "Fat")
  sodium<-data.frame(ID = cereal2$ID, Shelf = cereal2$Shelf, value = cereal2$sodium2, variable = "Sodium")
  all.cereal<-rbind.data.frame(sugar, fat, sodium)
  
  win.graph(width = 7, height = 7, pointsize = 9)

  histogram(formula = ~ value | variable + factor(Shelf), data = all.cereal, type = "percent", layout = c(3,4), 
          xlab = "Standardized value", as.table=TRUE)