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, ...)
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Hope to be clearer,
Thanks,
Alex
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