[R] passing variable names to dplyr

[David Winsemius]

On Jan 28, 2014, at 3:43 PM, Dennis Murphy wrote:

> David:
> 
> I privately suggested he post to manipulatr because Hadley is more
> likely to see his question there first than in R-help. He originally
> posted here, noted the cross-posting and referral at manipulatr and
> responded back to this list when he got a successful reply from
> Hadley. I don't see that he's done anything wrong; in fact, he's been
> exceptionally polite. If you want to yell at anybody, yell at me.

And after I replied I saw that he also posted a "solved" message in rhelp, a courtesy I do heartily endorse, so thank you, Roger. (If it were posted as a reply to his original question, I would not have sent anything. I didn't think I was yelling at anyone, just advising about list mores.)

-- 
David
> 
> Dennis
> 
> On Tue, Jan 28, 2014 at 3:33 PM, David Winsemius <dwinsemius at comcast.net> wrote:
>> 
>> On Jan 27, 2014, at 7:45 AM, Bos, Roger wrote:
>> 
>>> All,
>>> 
>>> I would like to figure out how to pass variable names to the dplyr function mutate.  For example, this works because hp is one of the variable names on mtcars:
>>> 
>>> mutate(mtcars, scale(hp))
>>> 
>>> Let's says I want to pass in the target variable instead of hard-coding the name, as follows:
>>> 
>>> target <- "hp"
>>> mutate(mtcars, scale(target))
>>> 
>>> That dones't work.  I read somewhere about using lapply, but that suggestion didn't work for me either:
>>> 
>>> target <- lapply("hp", as.symbol)
>>> mutate(mtcars, scale(target))
>>> 
>>> Does anyone know how to do this?
>> 
>> You cross-posted this to the manipulatr newsgroup (where it was addressed). Crossposting is a practice which is not appreciated in R lists.
>> 
>> --
>> 
>> David Winsemius
>> Alameda, CA, USA
>> 
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David Winsemius
Alameda, CA, USA