[R] Arguments to lm() within a function - object not found
Hi all,
I'm having some difficulty passing arguments into lm() from within a
function, and I was hoping someone wiser in the ways of R could tell me
what I'm doing wrong. I have the following:
lmwrap - function(...) {
wts - somefunction()
print(wts) # This works, wts has the values I expect
fit - lm(weights=wts,...)
return(fit)
}
If I call my function lmwrap, I get the the following error:
lmwrap(a~b)
Error in eval(expr, envir, enclos) : object wts not found
A traceback gives me the following:
8: eval(expr, envir, enclos)
7: eval(extras, data, env)
6: model.frame.default(formula = ..1, weights = wts, drop.unused.levels =
TRUE)
5: model.frame(formula = ..1, weights = wts, drop.unused.levels = TRUE)
4: eval(expr, envir, enclos)
3: eval(mf, parent.frame())
2: lm(weights = wts, ...)
1: wraplm(a ~ b)
It seems like whatever environment lm is trying to eval wts in doesn't
have it defined.
Could anyone tell me what I'm doing wrong?
As a sidenote, I do have a workaround, but this strikes me as really the
wrong thing to do. I replace the call to lm with:
eval(substitute(lm(weights = dummy,...),list(dummy=wts)))
which works.
Thanks
Pete
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[R] Arguments to lm() within a function - object not found
Hi all,
I'm having some difficulty passing arguments into lm() from within a
function, and I was hoping someone wiser in the ways of R could tell me
what I'm doing wrong. I have the following:
lmwrap - function(...) {
wts - somefunction()
print(wts) # This works, wts has the values I expect
fit - lm(weights=wts,...)
return(fit)
}
If I call my function lmwrap, I get the the following error:
lmwrap(a~b)
Error in eval(expr, envir, enclos) : object wts not found
A traceback gives me the following:
8: eval(expr, envir, enclos)
7: eval(extras, data, env)
6: model.frame.default(formula = ..1, weights = wts, drop.unused.levels =
TRUE)
5: model.frame(formula = ..1, weights = wts, drop.unused.levels = TRUE)
4: eval(expr, envir, enclos)
3: eval(mf, parent.frame())
2: lm(weights = wts, ...)
1: wraplm(a ~ b)
It seems like whatever environment lm is trying to eval wts in doesn't
have it defined.
Could anyone tell me what I'm doing wrong?
As a sidenote, I do have a workaround, but this strikes me as really the
wrong thing to do. I replace the call to lm with:
eval(substitute(lm(weights = dummy,...),list(dummy=wts)))
which works.
Thanks
Pete
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] Arguments to lm() within a function - object not found
Thanks very much for the quick reply. I had looked at the help for lm,
but I clearly skimmed over the critical part explaining where weights is
evaluated.
Thanks,
Pete
On 13/8/2008, Prof Brian Ripley wrote:
On Wed, 13 Aug 2008, Pete Berlin wrote:
Hi all,
I'm having some difficulty passing arguments into lm() from within a
function, and I was hoping someone wiser in the ways of R could tell me
what I'm doing wrong. I have the following:
lmwrap - function(...) {
wts - somefunction()
print(wts) # This works, wts has the values I expect
fit - lm(weights=wts,...)
return(fit)
}
If I call my function lmwrap, I get the the following error:
lmwrap(a~b)
Error in eval(expr, envir, enclos) : object wts not found
Correct. The help (?lm) says
All of 'weights', 'subset' and 'offset' are evaluated in the same
way as variables in 'formula', that is first in 'data' and then in
the environment of 'formula'.
A traceback gives me the following:
8: eval(expr, envir, enclos)
7: eval(extras, data, env)
6: model.frame.default(formula = ..1, weights = wts, drop.unused.levels =
TRUE)
5: model.frame(formula = ..1, weights = wts, drop.unused.levels = TRUE)
4: eval(expr, envir, enclos)
3: eval(mf, parent.frame())
2: lm(weights = wts, ...)
1: wraplm(a ~ b)
It seems like whatever environment lm is trying to eval wts in doesn't
have it defined.
Could anyone tell me what I'm doing wrong?
As a sidenote, I do have a workaround, but this strikes me as really the
wrong thing to do. I replace the call to lm with:
eval(substitute(lm(weights = dummy,...),list(dummy=wts)))
which works.
It's one workaround, but working with the scoping rules is better. Hint:
use the 'data' argument to lm.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
