[R] What does the : operator mean in glm formulas

[David Winsemius]

On Jan 19, 2012, at 8:02 AM, Xiaobo Gu wrote:

> Hi,
>
> I see the following is the credit scoreing in R guide :
>
> m2<-glm(formula = good_bad ~ checking + duration + history+ purpose  
> +amount + savings + employed + installp + marital +
> coapp +age + other + depends + telephon + foreign +checking:amount
>
> What does checking:amount mean?

?formula

-- 

David Winsemius, MD
West Hartford, CT