Displaying 2 results from an estimated 2 matches for "headwt".
2008 Oct 05
1
Help on R Coding
Hi all,
I am kind of stuck of using Predict function in R to make prediction
for a model with continuous variable and categorial variables. i have
no problem making the model, the model is e.g.
cabbage.lm2<- lm(VitC ~ HeadWt + Date + Cult)
HeadWt is a continuous variable, Date and Culte are factors. Date have
three levels inside (d16,d20,d21), Cult has two levels(c39,c52). I
need to calculate a confidence interval for the mean VitC for each
combination of Date and Cult, fixing the value of HeadWt at the mean
for the c...
2018 Apr 24
0
TukeyHSD and glht differ for models with a covariate
I have a question about TukeyHSD and the glht function because I'm
getting different answers when a covariate is included in model for
ANCOVA.? I'm using the cabbages dataset in the 'MASS' package for
repeatability.? If I include HeadWt as a covariate, then I get different
answers when performing multiple comparisons using TukeyHSD and the glht
function. The difference appears related to the predicted means used in
the Tukey posthoc test. The glht function uses the marginal means, which
I can obtain using the effect function i...