[R] apply formula to data?
ivo welch
ivowel at gmail.com
Tue May 11 14:35:46 CEST 2010
dear R wizards---
I am looking for a reference that explains how to work with formula
objects. for example, say, I have a formula which I want to use in an
NLS. I want to test what this formula to see if my function was
defined correctly. Is there a way to apply a formula to data? For
example,
my.formula = (y ~ a+b*x^2)
x= 1:10; a=2; b=3;
computed.y= apply.a.formula( my.formula, x, a, b )
I know that this has issues, not the least of which is that a formula
may not return a y. and that an lm() specification would require me
to infer that I have an implicit coefficient vector that is not even
specified (i.e., y~x really is y~a+b*x). so, is there a reference to
formula objects somewhere?
sincerely,
/iaw
----
Ivo Welch (ivo.welch at brown.edu, ivo.welch at gmail.com)
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