library(RODBC)
library(lattice)
library(treemap)

ch<-odbcConnect("mike_db",uid="mike")
c<-sqlQuery(ch, paste("select" 
,"ward,year(end_Dttm) as [year]"
,",sum(datediff(mi,start_Dttm,end_Dttm)/1440.0) as LOS"
,"from [wardstays_examples]"
,"GROUP BY ward ,year(end_Dttm)" 
))
str(c)

treemap (c
         ,index=c("year","ward") # the different levels
         ,vSize = "LOS" # the value on which to scale the squares
         )