Passing in arguments into function

Hi Paul,

You need to pass the formula object, not a string.  If you have a
function that is passing one of its arguments down to lm(), just pass
the argument directly, no need to do anything special.  Here are some
examples using a built in dataset:

## wrapper function
foo<- function(fooform, ...) {
   summary(lm(formula = fooform, ...))
}

## seeing it in action
foo(mpg ~ hp * wt, data = mtcars)

## save a formula in an object
myform<- mpg ~ hp * wt

## pass the object to foo() which passes it down
foo(myform, data = mtcars)

## pass the formula object "myform" directly to lm()
summary(lm(myform, data = mtcars))

Do one of those answer your question or do what you want?

Hope this helps,

Josh

On Sun, Jan 23, 2011 at 8:46 AM, Paul Evans<p.evans48 at yahoo.com>  wrote:

Hi,

I had a function that looked like:

diff<- lm(x ~ y + z)

How can I pass the argument to the 'lm' function on the fly? E.g., if I pass it
in as a string (e.g. "x ~ y + z"), then the lm function treats it as a string
and not a proper argument.

many thanks




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