Re: [R] use of poly()

2008-02-13 Thread Dylan Beaudette
gt; From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > On Behalf Of Dylan Beaudette > Sent: Thursday, 14 February 2008 6:42 AM > To: r-help@r-project.org > Subject: [R] use of poly() > > Hi, > > I am curious about how to interpret the results of a polynomial > regression-- &g

Re: [R] use of poly()

2008-02-13 Thread Bill.Venables
: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dylan Beaudette Sent: Thursday, 14 February 2008 6:42 AM To: r-help@r-project.org Subject: [R] use of poly() Hi, I am curious about how to interpret the results of a polynomial regression-- using poly(raw=TRUE) vs. poly(raw=FALSE). set.seed(123

[R] use of poly()

2008-02-13 Thread Dylan Beaudette
Hi, I am curious about how to interpret the results of a polynomial regression-- using poly(raw=TRUE) vs. poly(raw=FALSE). set.seed(123456) x <- rnorm(100) y <- jitter(1*x + 2*x^2 + 3*x^3 , 250) plot(y ~ x) l.poly <- lm(y ~ poly(x, 3)) l.poly.raw <- lm(y ~ poly(x, 3, raw=TRUE)) s <- seq(-3, 3,