lm coefficients
On Tue, 3 Feb 2004, Timur Elzhov wrote:
Dear R experts, Excuse me if my question will be stupid... I'd like to fit data with x^2 polynomial:
<snip>
out <- lm(T ~ poly(X, 4), data = d)
out
Call:
lm(formula = T ~ poly(X, 2), data = d)
Coefficients:
(Intercept) poly(X, 2)1 poly(X, 2)2
9.803 -108.075 51.007
So, d$T best fitted with function
9.803 -108.075 * X + 51.007 * X^2,
No. The predictors are not X and X^2, but two orthogonal polynomials. Look at the help page for poly(). -thomas