#
# EPage 138
#
# Written by:
# -- 
# John L. Weatherwax                2009-04-21
# 
# email: wax@alum.mit.edu
# 
# Please send comments and especially bug reports to the
# above email address.
# 
#-----

library(DAAG)

nswpsid3 = rbind( psid3, subset(nswdemo, trt==1) )

nCols = dim( nswpsid3 )[2]

bInds_control = nswpsid3[,1] == 0
bInds_treated = nswpsid3[,1] == 1

oldpar = par(mfrow=c(3,3))

for( ci in 2:nCols ){

  # Split analysis of continuous variables appart from the discrete variables:
  #
  if( ci %in% c(4,5,6,7) ){
    # A discrete variable:
    #
    print( table( nswpsid3[,c(1,ci)] ) )
  }else{
    
    # A continuous variable:
    # 
    d_treated = density( nswpsid3[bInds_treated,ci], na.rm=TRUE )
    d_control = density( nswpsid3[bInds_control,ci], na.rm=TRUE )

    min_x = min( min(d_control$x), min(d_treated$x) )
    max_x = max( max(d_control$x), max(d_treated$x) )

    min_y = min( min(d_control$y), min(d_treated$y) )
    max_y = max( max(d_control$y), max(d_treated$y) )

    plot( d_control, col="red", xlim=c(min_x,max_x), ylim=c(min_y,max_y), main=colnames(nswpsid3)[ci] )
    lines( d_treated, col="green", xlim=c(min_x,max_x), ylim=c(min_y,max_y) )
  }
  
}

par(oldpar)