damn.
My apologies to everyone -- I sent one message and it got destroyed somehow.
Here's the part that was missing, which led to rather a lot of confusion
on all parts.
The two recent responses to a question about lm suggested
1) lm(y~poly(x,2))
2) lm(y~I(x^2))
So my question was *supposed* to be related to how lm operated
differently (if at all) on these two different 'versions' of a quadratic
fit. My gut reaction was that y~I(x^2) would not be the same as y~f(x)
where f(x) is a+bx+cx^2 .
So what I was trying to find out was just how lm() deals with various
definitions of the orthogonal polynomials its presented with. Another
way, maybe, to ask, is: how does one specify to fit exactly to
a + bx +cx^2 vs
bx + cx^2 vs
cx^2
?
Thanks and apologies again to all the people who quite properly
misunderstood what I was harping on due to the munging of my first post.
Carl
David Winsemius wrote:
On Jan 12, 2009, at 5:57 PM, Carl Witthoft wrote:
Well..... *_* ,
I think it should have been clear that this was not a question for
which any code exists. In fact, I gave two very specific examples of
function calls.
Huh? I think most of the readers of the list saw a basically empty
message body. That was the point of Berry's "[nothing deleted]". If you
are under the belief that this is a continuation of an earlier question,
then it may not be threading up in the manner you hoped for.
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