OK!
   
  # The R codes to generate the Trellis plot are from the R help archive by Karl Ove Hufthammer
   
  panel.estcontplot <- function(x, y, ..., pretty=TRUE, region=FALSE)
{
  cest.gr=kde2d(x, y)
  cest.gr.lat=con2tr(cest.gr)
  panel.contourplot(cest.gr.lat$x, cest.gr.lat$y, cest.gr.lat$z,
                   subscripts = seq(nrow(cest.gr.lat)),
                   pretty=pretty, region=region, contour=TRUE, ...)
}
   
  # The titanic3 dataset is from http://biostat.mc.vanderbilt.edu/twiki/pub/Main/DataSets/titanic3.xls with missing value imputations according to the book
   
  library(Hmisc)
set.seed(17)
xtrans <- transcan(~ I(age) + pclass + sex + sibsp + parch + survived, data = titanic3,
            n.impute=5, pl=F, trantab=T, imputed=T, transformed=TRUE)
titanic3[ ,'age'] <- xtrans$transformed[ ,'age']
titanic3[ ,'survived'] <- as.factor(titanic[ ,'survived'])
   
  library(lattice)
  xyplot(age ~ sibsp | survived, data = titanic3, panel=panel.estcontplot)
   
   
  Anyway, I realized that Trellis could only be conditional on the categorical variable while what I really want is conditional density plot of survived on the two covariates.  Thus I tried to twist cdplot with kde2d to substitute density.
   
  http://www.geocities.com/useebi/data/cdplot2d.txt
   
  However, I still have no success.  Would anyone help, please!
   
  Thanks
  marco
  

Deepayan Sarkar <deepayan.sarkar@gmail.com> wrote:
  On 10/24/06, Marco LO wrote:
> Hello All,
>
> I've problems to interpret the contourplot for a binary response dependent variable. For example, I ploted the survived probability for the titanic3 dataset,
>
> http://www.geocities.com/useebi/data/CondenContour.jpeg
>
> Trellis displayed two panels of contour, one for dead and one for alive. However,
> the contours between the two panels didn't conform to the rule of prob(dead) =
> 1 - prob(alive). How I should read the contours? What I did wrongly?

Hard to say, since we have no idea what you actually did. As the
footer of every r-help message says:

PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

-Deepayan

> Is there an example that I could follow?
>
> Thanks!
> marco


 				
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