Re: [Rd] model.frame(), model.matrix(), and derived predictor variables

2013-08-29 Thread Gabriel Becker
On Thu, Aug 29, 2013 at 6:21 AM, Ben Bolker wrote: > On 13-08-28 05:43 PM, Gabriel Becker wrote: > > Ben, > > > > It works for me ... > >> x = rpois(100, 5) + 1 > >> y = rnorm(100, x) > >> d = data.frame(x,y) > >> m <- lm(y~log(x),d) > >> update(m,data=model.frame(m)) > > > > Call: > > lm(formula

Re: [Rd] model.frame(), model.matrix(), and derived predictor variables

2013-08-29 Thread Ben Bolker
On 13-08-28 05:43 PM, Gabriel Becker wrote: > Ben, > > It works for me ... >> x = rpois(100, 5) + 1 >> y = rnorm(100, x) >> d = data.frame(x,y) >> m <- lm(y~log(x),d) >> update(m,data=model.frame(m)) > > Call: > lm(formula = y ~ log(x), data = model.frame(m)) > > Coefficients: > (Intercept)

Re: [Rd] model.frame(), model.matrix(), and derived predictor variables

2013-08-28 Thread Gabriel Becker
Ben, It works for me ... > x = rpois(100, 5) + 1 > y = rnorm(100, x) > d = data.frame(x,y) > m <- lm(y~log(x),d) > update(m,data=model.frame(m)) Call: lm(formula = y ~ log(x), data = model.frame(m)) Coefficients: (Intercept) log(x) -4.0105.817 You can also re-fit using the

Re: [Rd] model.frame(), model.matrix(), and derived predictor variables

2013-08-24 Thread Ben Bolker
Bump: just trying one more time to see if anyone had thoughts on this (so far it's just ...) Original Message Subject: model.frame(), model.matrix(), and derived predictor variables Date: Sat, 17 Aug 2013 12:19:58 -0400 From: Ben Bolker To: r-de...@stat.math.ethz.ch De

[Rd] model.frame(), model.matrix(), and derived predictor variables

2013-08-17 Thread Ben Bolker
Dear r-developers: I am struggling with some fundamental aspects of model.frame(). Conceptually, I think of a flow from data -> model.frame() -> model.matrix; the data contain _input variables_, while model.matrix contains _predictor variables_: data have been transformed, splines and poly