[R] Rpart and case weights: working with functions

[Xavier Robin]

S Ellison a écrit :
> As a work-round, try something lik
> 
> test.function <- function (formula.str, data) {
>    weights <- rep(.1, 8)
>    rpart(as.formula(formula.str), data, weights)
> }
> 
> which works if formula.str is a string instead of a formula object.

Ok, I think I got the point. The only problem with transforming the 
string to a formula is that rpart raises another error:
> Error in t.default(x) : argument is not a matrix


> test.function <- function (form, data) {
>    weights <- rep(.1, 8)
>    environment(form)<-environment() #re-sets the formula environment   
>    rpart(form, data, weights)
> }

This works perfectly well. It will be good enough for what I need.

Thanks a lot ;-)

Xavier