Changing reference group for categorical predictor variable in logistic regression

Question

I\'m running a logistic regression with a categorical predictor variable with levels 0-6. By default, R considers level 0 as the reference group.

How can I tell R to

Answer 1

Use the C function to define your contrasts in the dataframe.

If your dataframe is DF and the factor variable is fct, then

DF$fct <- C(DF$fct, contr.treatment, base=3)

(untested).