Could someone explain the reasoning behind choosing the dependent trait in pairwise logistic regression of two categorical traits. My hypothesis does not explicitly state which trait is the IV as I just need the relationship between traits. To word this another way, I dont understand theoretically why the directioning in the model is important.

I have ~100 traits of a binary (presence/absence) type and am running pairwise logistic regressions on each trait combination using an R package that fits phylogeny as a covariant.

Code:

`phyloglm(trait[,i]~trait[,j], data=datafile, phy=treedata, method = c("MPLE","IG10"))`

Code:

`logreg$loglik`

[1] -6.276559

Code:

`logreg$loglik`

[1] -67.33166

My overall plan is to compare the divergence of a phylogenetic model with a standard logistic regression (subtract log likelihoods), but need to understand why swapping the model around gives different results first.

I would appreciate any suggestions here.

Cheers,

Lesley ]]>

For bivariate regression, what can the normal probability plots of the residuals of the conditional functions tell me?

Like the normal probability plot of the residuals for f(Y|X) and the normal probability plot of the residuals for f(X|Y).

What can I tell about about X and Y from these plots? Can I tell if the conditional models are a good fit? Can I tell if the joint distribution is normal too?

Thanks for any help. ]]>

Need help to develop a model for the data set.

I have attached a copy of all the variables with their parameter estimates and the p value.

I want to calculate a predicted price value by using these variables.

I proceeded by:

PROC REG DATA=linearreg1;

MODEL Price = Mileage cylinder liter doors cruise leather sound Make1 Buick1 cadil1 chevr1 ponti1 type1 conve1 hatch1;

Run;

Now the P value for cruise sound and leather is >.05.

Should I drop these variable from by calaculation? or

:wave:Is there a way to calculate the predicted price for the dataset by including all the variable and fitting them within a significance level of <.05 ?

cruise leather sound Make1 Buick1 cadil1 chevr1 ponti1 type1 conve1 hatch1 are all dummy variable with 1 or 0 value.

Thanks in advance!