On Nov 15, 2009, at 11:15 AM, Karsten Weinert wrote:
Hello David,
of course I read those help pages and searched the r-help archive.
But did you look at the as.formula page?
I agree that the way should be clear, but I am stuck and looking for
help. Here is reproducible code
And here is what seemed like the obvious extension of your example but
using as.formula:
myData <- data.frame(x1=rnorm(10), x2=rnorm(10), x3=rnorm(10),
y=rnorm(10))
fit <- lm(y~x1+x2+x3, data=myData)
remvterm <- function(ft, termname) update(ft, as.formula(paste(".~.-",
termname, sep="")))
remvterm(fit, "x3")
Call:
lm(formula = y ~ x1 + x2, data = myData)
Coefficients:
(Intercept) x1 x2
-0.2598 -0.0290 -0.2645
--
David
removeTerm1 <- function(linModel, termName) { update(linModel, .~. -
termName) }
removeTerm2 <- function(linModel, termName) { update(linModel, .~. -
as.name(termName)) }
removeTerm3 <- function(linModel, termName) { update(linModel, .~. -
eval(termName)) }
removeTerm4 <- function(linModel, termName) { update(linModel, .~. -
eval.parent(termName)) }
removeTerm5 <- function(linModel, termName) { update(linModel, .~. -
get(termName)) }
myData <- data.frame(x1=rnorm(10), x2=rnorm(10), x3=rnorm(10),
y=rnorm(10))
fit <- lm(y~x1+x2+x3, data=myData)
# all this does not work, as I am expecting the function to return a
lm object with formula y~x2+x3
removeTerm1(fit, "x1")
removeTerm2(fit, "x1")
removeTerm3(fit, "x1")
removeTerm4(fit, "x1")
removeTerm5(fit, "x1")
Any help appreciated,
kind regards,
Karsten Weinert
2009/11/15 David Winsemius <dwinsem...@comcast.net>:
You need to review:
?update
?update.formula
?as.formula
The way should be clear at that point. If not, then include a
reproducible
data example to work with.
--
David
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
