can two glm models show an interaction with each other? what is the degree of freedom of the variables in anova? which variables in anova have zero degree of freedom why does anova report df what is adf which of the following variables cannot be used in a glm model? what variables can i get out of my anova why is anova input zero what is the relationship between two variables in a glm r how to get df for anova why is the df of an anova model zero what is df in r which factor is a value for a glm model which factor is missing in anova why do variables go to zero in r what variables are in a glm how to find out which factor is missing in anova when you add two variables to a model, the degrees of freedom in r are zero what variables are in the anova table why does an anova model always go to zero?