Expand data.frame into a design matrix

Expands out a data.frame using a formula to create a design matrix. Key details are that it will always place the outcome variable into the first column of the return object.

Usage

as_model_df(dat, frm)

Arguments

dat: a data.frame
frm: a formula

Details

The outcome column may contain NA's but none of the other variables listed in the formula should contain missing values