R help - Nov 2015 - summarize_ (NSE) in combination with quantile not working

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]]

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]]
>
>______________________________________________
>R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>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.
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.
	[[alternative HTML version deleted]]

> On Nov 21, 2015, at 3:33 PM, 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"
You should have noticed that the error had double-quotes around the function
name. That?s very un-Rlich. You should have been satisfied with the third
variation.

> 
> 
> It seems to me, that the combination of summarise_ and quantile() 
> somehow doesn't work.
> 
If thine code offends thee, pluck it out.

? 
David.
> Does anyone have an idea what the issue here is?
> 
> Thanks a lot!
> 
> Regards
> Tobi
> 
> 	[[alternative HTML version deleted]]
And while you are at it can you pluck out the HTML???????
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
David Winsemius
Alameda, CA, USA

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]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> 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.
>