From john.maindonald at anu.edu.au  Sun May  8 09:25:56 2011
From: john.maindonald at anu.edu.au (John Maindonald)
Date: Sun, 8 May 2011 17:25:56 +1000
Subject: [Rd] anova.lm fails with test="Cp"
Message-ID: <0E28A214-9F72-45A2-AAA2-E1D7EC46C6B1@anu.edu.au>

Here is an example, modified from the help page to use test="Cp":

--------------------------------------------------------------------------------
> fit0 <- lm(sr ~ 1, data = LifeCycleSavings)
> fit1 <- update(fit0, . ~ . + pop15)
> fit2 <- update(fit1, . ~ . + pop75)
> anova(fit0, fit1, fit2, test="Cp")
Error in `[.data.frame`(table, , "Resid. Dev") : 
 undefined columns selected
> sessionInfo()
R version 2.13.0 Patched (2011-04-28 r55678)
Platform: i386-pc-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=English_United States.1252 
[2] LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
[1] tools_2.13.0

--------------------------------------------------------------------------------------

The help page says for  "test:" 	
"a character string specifying the test statistic to be used. 
Can be one of "F", "Chisq" or "Cp", with partial matching allowed, 
or NULL for no test."

test="Cp" is, following the help page, intended to work?  Setting
the scale parameter does not help.

John Maindonald             email: john.maindonald at anu.edu.au
phone : +61 2 (6125)3473    fax  : +61 2(6125)5549
Centre for Mathematics & Its Applications, Room 1194,
John Dedman Mathematical Sciences Building (Building 27)
Australian National University, Canberra ACT 0200.
http://www.maths.anu.edu.au/~johnm



[Rd] anova.lm fails with test="Cp"
John Maindonald