R error which says “Models were not all fitted to the same size of dataset”

Question

I have created two generalised linear models as follows:

glm1 <-glm(Y ~ X1 + X2 + X3, family=binomial(link=logit))

glm2 <-glm(Y ~ X1 + X2, family=bino         


        

Answer 1

I'm guessing that you meant to type:

glm1 <-glm(Y ~ X1+X2+X3, family=binomial(link=logit))

glm2 <-glm(Y ~ X1 + X2, family=binomial(link=logit))

The formula interface for R regression functions does not recognize commas as adding covariates to the RHS of the formula. And don't use attach(); use the data argument to regression functions.