R devel - Aug 2016 - summary.default rounding on numeric seems inconsistent with other R behaviors

I was wondering if it would make sense to change the default behavior of the
following:

summary(15555L)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   15560   15560   15560   15560   15560   15560 

summary.default on numeric values rounds values (not just presentation) to
getOption("digits")-3L (or four) digits by default, making those
values surprising and less suitable for further calculation.  Summary on matrix
and data.frame do not do so.

It seems it would be nice to have x=15555L; summary(x)[['Min.']] ==
min(x) evaluate to TRUE.  I know one can alter behavior by changing the global
?digits? option, but I don?t know what other impacts that might have.  Ideally I
would think summary.default would not round its values at all, but use digits to
control presentation (by overriding print and such).  Even in presentation the
rounding without switching to scientific notation (such as 1.556e+4) is a bit
surprising (I understand rounding and scientific notation are two different
presentation issues, but new users are very confused that something that appears
to be an integer has been rounded).

Example:

summary(data.frame(x=15555))
##        x        
##  Min.   :15555  
##  1st Qu.:15555  
##  Median :15555  
##  Mean   :15555  
##  3rd Qu.:15555  
##  Max.   :15555  
summary(15555)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   15560   15560   15560   15560   15560   15560 

I have a (bit whiny) polemic trying to explain the pain point here
http://www.win-vector.com/blog/2016/08/my-criticism-of-r-numeric-summary/
<http://www.win-vector.com/blog/2016/08/my-criticism-of-r-numeric-summary/>
(I am not trying to be rude, more I am trying to emphasize why this can be
confusing to new users).



---------------
John Mount
http://www.win-vector.com/ <http://www.win-vector.com/> 
Our book: Practical Data Science with R http://www.manning.com/zumel/
<http://www.manning.com/zumel/>




	[[alternative HTML version deleted]]

Concur.
I would argue the issue is more critical when sharing results (say
summary() in a RMarkdown) with our business partners.



On Fri, Aug 19, 2016 at 8:04 AM, John Mount <jmount at win-vector.com>
wrote:
> I was wondering if it would make sense to change the default behavior of
> the following:
>
> summary(15555L)
> ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
> ##   15560   15560   15560   15560   15560   15560
>
> summary.default on numeric values rounds values (not just presentation) to
> getOption("digits")-3L (or four) digits by default, making those
values
> surprising and less suitable for further calculation.  Summary on matrix
> and data.frame do not do so.
>
> It seems it would be nice to have x=15555L; summary(x)[['Min.']] ==
min(x)
> evaluate to TRUE.  I know one can alter behavior by changing the global
> ?digits? option, but I don?t know what other impacts that might have.
> Ideally I would think summary.default would not round its values at all,
> but use digits to control presentation (by overriding print and such).
> Even in presentation the rounding without switching to scientific notation
> (such as 1.556e+4) is a bit surprising (I understand rounding and
> scientific notation are two different presentation issues, but new users
> are very confused that something that appears to be an integer has been
> rounded).
>
> Example:
>
> summary(data.frame(x=15555))
> ##        x
> ##  Min.   :15555
> ##  1st Qu.:15555
> ##  Median :15555
> ##  Mean   :15555
> ##  3rd Qu.:15555
> ##  Max.   :15555
> summary(15555)
> ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
> ##   15560   15560   15560   15560   15560   15560
>
> I have a (bit whiny) polemic trying to explain the pain point here
> http://www.win-vector.com/blog/2016/08/my-criticism-of-r-numeric-summary/
>
<http://www.win-vector.com/blog/2016/08/my-criticism-of-r-numeric-summary/>
> (I am not trying to be rude, more I am trying to emphasize why this can be
> confusing to new users).
>
>
>
> ---------------
> John Mount
> http://www.win-vector.com/ <http://www.win-vector.com/>
> Our book: Practical Data Science with R http://www.manning.com/zumel/ <
> http://www.manning.com/zumel/>
>
>
>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel



-- 

Best,
Jim Porzak
DS4CI.org  <http://www.ds4ci.org/>
LinkedIn.com/in/JimPorzak <http://www.linkedin.com/in/jimporzak>
use R! Group SF: meetup.com/R-Users/ <http://www.meetup.com/R-Users/>
R Beginners, Berkeley: meetup.com/r-enthusiasts/
<http://www.meetup.com/r-enthusiasts/>

	[[alternative HTML version deleted]]

John,

I had raised the matter ten years ago, and I was told that the topic was
already very^3 old

https://stat.ethz.ch/pipermail/r-devel/2006-September/042684.html

there is some discussion on its origin and also a declaration of intents to
change the default behaviour, which, unfortunately, remained a declaration.
I agree that R could do better here, let's hope in less than ten years
though. ;-)

Kind regards,

Simone

On Fri, Aug 19, 2016 at 5:04 PM, John Mount <jmount at win-vector.com>
wrote:
> I was wondering if it would make sense to change the default behavior of
> the following:
>
> summary(15555L)
> ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
> ##   15560   15560   15560   15560   15560   15560
>
> summary.default on numeric values rounds values (not just presentation) to
> getOption("digits")-3L (or four) digits by default, making those
values
> surprising and less suitable for further calculation.  Summary on matrix
> and data.frame do not do so.
>
> It seems it would be nice to have x=15555L; summary(x)[['Min.']] ==
min(x)
> evaluate to TRUE.  I know one can alter behavior by changing the global
> ?digits? option, but I don?t know what other impacts that might have.
> Ideally I would think summary.default would not round its values at all,
> but use digits to control presentation (by overriding print and such).
> Even in presentation the rounding without switching to scientific notation
> (such as 1.556e+4) is a bit surprising (I understand rounding and
> scientific notation are two different presentation issues, but new users
> are very confused that something that appears to be an integer has been
> rounded).
>
> Example:
>
> summary(data.frame(x=15555))
> ##        x
> ##  Min.   :15555
> ##  1st Qu.:15555
> ##  Median :15555
> ##  Mean   :15555
> ##  3rd Qu.:15555
> ##  Max.   :15555
> summary(15555)
> ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
> ##   15560   15560   15560   15560   15560   15560
>
> I have a (bit whiny) polemic trying to explain the pain point here
> http://www.win-vector.com/blog/2016/08/my-criticism-of-r-numeric-summary/
>
<http://www.win-vector.com/blog/2016/08/my-criticism-of-r-numeric-summary/>
> (I am not trying to be rude, more I am trying to emphasize why this can be
> confusing to new users).
>
>
>
> ---------------
> John Mount
> http://www.win-vector.com/ <http://www.win-vector.com/>
> Our book: Practical Data Science with R http://www.manning.com/zumel/ <
> http://www.manning.com/zumel/>
>
>
>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel



-- 
___________________________________________________

Simone Giannerini
Dipartimento di Scienze Statistiche "Paolo Fortunati"
Universita' di Bologna
Via delle belle arti 41 - 40126  Bologna,  ITALY
Tel: +39 051 2098262  Fax: +39 051 232153
http://www2.stat.unibo.it/giannerini/
___________________________________________________

	[[alternative HTML version deleted]]

It is the old story of defined behaviour and expected outcomes. Hard to
change now.

So I would suggest you do something like this in your ~/.Rprofile:

R> smry <- function(...) summary(..., digits=6)
R> smry(155555L)
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
 155555  155555  155555  155555  155555  155555
R>

Maybe call it Summary() instead.

Dirk

-- 
http://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org