[R] performing type III

[Hardouin Loïc]

Sorry to have not precised that I used the anova function in the car 
package but I did.
I try to fit clutch size with two covariables and a factor (with two 
levels). My purpose is to compare results with type I and III sum of 
squares and furhter perform model simplification. The data set contains 
no missing value.
The model run and provided only type I response with the warning message 
(see below)

 > sq<-lm(tponte~logavril*reldponte*exp,data=wa,contrasts=sum)
 > anova(sq,type=c("I","III"))
Analysis of Variance Table

Response: tponte
                       Df Sum Sq Mean Sq F value    Pr(>F) 
 logavril                 1 27.930  27.930 52.5041 1.385e-11 ***
reldponte                1 23.442  23.442 44.0670 3.984e-10 ***
exp                      1  2.657   2.657  4.9940   0.02672 *
logavril:reldponte       1  0.281   0.281  0.5292   0.46795  
logavril:exp             1  0.925   0.925  1.7383   0.18911 
reldponte:exp            1  0.016   0.016  0.0307   0.86105  
logavril:reldponte:exp   1  1.052   1.052  1.9771   0.16150  
Residuals              172 91.497   0.532                     ---
 
Warning message:
Models with response "NULL" removed because response differs from model 
1 in: anova.lmlist(object, ...)
 >

Hope to be clearer,
Thanks,

Alex

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