[R] summarize_ (NSE) in combination with quantile not working

[Sébastien Durier]

Hello,

A more explicit response can be found in :
https://cran.r-project.org/web/packages/lazyeval/vignettes/lazyeval.html
where it is explained that :
"quoted called and strings don’t have environments associated with them, 
so as.lazy() defaults to using baseenv(). This will work if the 
expression is self-contained (i.e. doesn’t contain any references to 
variables in the local environment), and will otherwise fail quickly and 
robustly."
So summarise_ seems to work with "min" because this function is in the 
base package, but not with "quantile" which is in the stats package.
A solution using strings could be :
summarise_(mtcars, "stats::quantile(mpg, 0.1)")

SD

On 22/11/2015 03:15, Jeff Newmiller wrote:
> Please post using plain text. The following works.
>
> mutate %>% summarise_( ~quantile( mpg, 0.1 ) )
>
> Read the vignette on nse that comes with dplyr,  or Google the error message.
>
> On November 21, 2015 3:33:16 PM PST, Tobias Byland <tobias at byland.info> wrote:
>> Hi everyone,
>>
>> I am stumbling over the following issue when using the NSE
>> (non-standard
>> evaluation) of the summarise function in dpylr (as described here:
>> https://cran.r-project.org/web/packages/dplyr/vignettes/nse.html):
>>
>> mtcars  %>% summarise(min(mpg))      # summarize and min
>> mtcars  %>% summarise_("min(mpg)")   # summarize_ and min
>> mtcars  %>% summarise(quantile(mpg, 0.1))   # summarize and quantile
>> mtcars  %>% summarise_("quantile(mpg, 0.1)")   # summarize_ and
>> quantile  -> ERROR
>>
>> The last (and only the last) call results in the following error:
>>
>> Error: could not find function "quantile"
>>
>>
>> It seems to me, that the combination of summarise_ and quantile()
>> somehow doesn't work.
>>
>> Does anyone have an idea what the issue here is?
>>
>> Thanks a lot!
>>
>> Regards
>> Tobi
>>
>> 	[[alternative HTML version deleted]]
>>
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>