R help - Mar 2008 - Use of ellipses ... in argument list of optim(), integrate(), etc.

Hi,

 

I have noticed that there is a change in the use of ellipses or . in R
versions 2.6.1 and later.  In versions 2.5.1 and earlier, the . were always
at the end of the argument list, but in 2.6.1 they are placed after the main
arguments and before method control arguments.  This results in the user
having to specify the exact (complete) names of the control arguments, i.e.
partial matching is not allowed.  

 

An example with integrate() : 

 
> integrate(function(x) exp(-x^2), lower=-Inf, upper=L, subdiv=1000)
 

Error in f(x, ...) : unused argument(s) (subdiv = 1000)

 
> integrate(function(x) exp(-x^2), lower=-Inf, upper=L, subdivisions=1000)
 

1.633051 with absolute error < 1.6e-06

 

 

Here is an example with optim():

 
> res <- optim(50, fw, meth="BFGS", control=list(maxit=20000,
temp=20,
parscale=20)) 

 

Error in fn(par, ...) : unused argument(s) (meth = "BFGS")

 

 

FYI, I am using R version 2.6.1 on Windows XP.

 

May I ask what the rationale behind this change is and also about the pros
and cons of the two different ways of specifying (.)?

 

Thank you very much.

 

Best,

Ravi.

 

----------------------------------------------------------------------------
-------

Ravi Varadhan, Ph.D.

Assistant Professor, The Center on Aging and Health

Division of Geriatric Medicine and Gerontology 

Johns Hopkins University

Ph: (410) 502-2619

Fax: (410) 614-9625

Email: rvaradhan@jhmi.edu

Webpage:  http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html

 

----------------------------------------------------------------------------
--------

 


	[[alternative HTML version deleted]]

From the NEWS file:

CHANGES IN R VERSION 2.6.0
SIGNIFICANT USER-VISIBLE CHANGES
  o	integrate(), nlm(), nlminb(), optim(), optimize() and uniroot()  
now have '...' much earlier in their argument list. This reduces the  
chances of unintentional partial matching but means that the later  
arguments must be named in full.

---
   Vincent Goulet, Associate Professor
   ?cole d'actuariat
   Universit? Laval, Qu?bec
   Vincent.Goulet at act.ulaval.ca   http://vgoulet.act.ulaval.ca

Le jeu. 13 mars ? 12:05, Ravi Varadhan a ?crit :
> Hi,
>
>
>
> I have noticed that there is a change in the use of ellipses or . in R
> versions 2.6.1 and later.  In versions 2.5.1 and earlier, the . were  
> always
> at the end of the argument list, but in 2.6.1 they are placed after  
> the main
> arguments and before method control arguments.  This results in the  
> user
> having to specify the exact (complete) names of the control  
> arguments, i.e.
> partial matching is not allowed.
>
> An example with integrate() :
>
>> integrate(function(x) exp(-x^2), lower=-Inf, upper=L, subdiv=1000)
>
> Error in f(x, ...) : unused argument(s) (subdiv = 1000)
>
>> integrate(function(x) exp(-x^2), lower=-Inf, upper=L,  
>> subdivisions=1000)
>
> 1.633051 with absolute error < 1.6e-06
>
> Here is an example with optim():
>
>> res <- optim(50, fw, meth="BFGS",
control=list(maxit=20000, temp=20,
> parscale=20))
>
> Error in fn(par, ...) : unused argument(s) (meth = "BFGS")
>
> FYI, I am using R version 2.6.1 on Windows XP.
>
> May I ask what the rationale behind this change is and also about  
> the pros
> and cons of the two different ways of specifying (.)?
>
> Thank you very much.
>
> Best,
>
> Ravi.
>
> ------------------------------------------------------------
> Ravi Varadhan, Ph.D.
> Assistant Professor, The Center on Aging and Health
> Division of Geriatric Medicine and Gerontology
> Johns Hopkins University
> Ph: (410) 502-2619
> Fax: (410) 614-9625
> Email: rvaradhan at jhmi.edu
> Webpage:  http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html
>
----------------------------------------------------------------------------

Ravi Varadhan wrote:
> Hi,
> 
> I have noticed that there is a change in the use of ellipses or . in R
> versions 2.6.1 and later.  In versions 2.5.1 and earlier, the . were always
> at the end of the argument list, but in 2.6.1 they are placed after the
main
> arguments and before method control arguments.  This results in the user
> having to specify the exact (complete) names of the control arguments, i.e.
> partial matching is not allowed.  
> 
> An example with integrate() : 
> 
>> integrate(function(x) exp(-x^2), lower=-Inf, upper=L, subdiv=1000)
> 
> Error in f(x, ...) : unused argument(s) (subdiv = 1000)
> 
>> integrate(function(x) exp(-x^2), lower=-Inf, upper=L,
subdivisions=1000)
> 
> 1.633051 with absolute error < 1.6e-06
> 
> Here is an example with optim():
> 
>> res <- optim(50, fw, meth="BFGS",
control=list(maxit=20000, temp=20,
> parscale=20)) 
> 
> Error in fn(par, ...) : unused argument(s) (meth = "BFGS")
> 
> FYI, I am using R version 2.6.1 on Windows XP.
> 
> May I ask what the rationale behind this change is and also about the pros
> and cons of the two different ways of specifying (.)?
Putting optim() arguments after the ... disallows the use of abbreviated 
actual arguments for optim().  This is generally a good thing, because 
prior to this change, it was impossible to supply, via the '...'
arguments
of optim(), an argument to fn() whose name was a prefix of one of the 
arguments of optim().  E.g., if your function had a argument named 'm',
you
could not previously supply it via the '...' argument of optim(),
because
if you did something like optim(x, fun, m=240), intending 'm' to be
passed
to 'fun', the 'm' would instead match the 'method'
argument of optim().

The cons of the new argument structure are that abbreviations for names of 
arguments of optim() can't be used (a minor and debatable con), and that 
previous code that used abbreviations might break, but it will likely break 
quickly and noisily, so it's not too bad (the only case where it
wouldn't
break is when fn has a '...' argument itself, and it ignores
unrecognized
components, or where the are other argument name collisions).

-- Tony Plate
> 
>  
> 
> Thank you very much.
> 
>  
> 
> Best,
> 
> Ravi.
> 
>  
> 
>
----------------------------------------------------------------------------
> -------
> 
> Ravi Varadhan, Ph.D.
> 
> Assistant Professor, The Center on Aging and Health
> 
> Division of Geriatric Medicine and Gerontology 
> 
> Johns Hopkins University
> 
> Ph: (410) 502-2619
> 
> Fax: (410) 614-9625
> 
> Email: rvaradhan at jhmi.edu
> 
> Webpage:  http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html
> 
>  
> 
>
----------------------------------------------------------------------------
> --------
> 
>  
> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list
> 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.
>

There is an entry in the NEWS file for 2.6.0:

 		CHANGES IN R VERSION 2.6.0


SIGNIFICANT USER-VISIBLE CHANGES

     o	integrate(), nlm(), nlminb(), optim(), optimize() and uniroot()
 	now have '...' much earlier in their argument list.  This
 	reduces the chances of unintentional partial matching but
 	means that the later arguments must be named in full.

and there was a spate of instances of 'unintentional partial matching'
at
the time.

I have have no idea what you mean by 'ellipses or .' -- this is
literally
'...', and ellipses (e.g. Unicode U+226) do not work. From 
http://en.wikipedia.org/wiki/Ellipsis

   Most programming languages other than Perl6 require the ellipsis to be
   written as a series of periods; a single (Unicode) ellipsis character
   cannot be used.

Please use R-devel for questions about the design and development of R 
(see the posting guide).


On Thu, 13 Mar 2008, Ravi Varadhan wrote:
> Hi,
>
>
>
> I have noticed that there is a change in the use of ellipses or . in R
> versions 2.6.1 and later.  In versions 2.5.1 and earlier, the . were always
> at the end of the argument list, but in 2.6.1 they are placed after the
main
> arguments and before method control arguments.  This results in the user
> having to specify the exact (complete) names of the control arguments, i.e.
> partial matching is not allowed.
>
>
>
> An example with integrate() :
>
>
>
>> integrate(function(x) exp(-x^2), lower=-Inf, upper=L, subdiv=1000)
>
>
>
> Error in f(x, ...) : unused argument(s) (subdiv = 1000)
>
>
>
>> integrate(function(x) exp(-x^2), lower=-Inf, upper=L,
subdivisions=1000)
>
>
>
> 1.633051 with absolute error < 1.6e-06
>
>
>
>
>
> Here is an example with optim():
>
>
>
>> res <- optim(50, fw, meth="BFGS",
control=list(maxit=20000, temp=20,
> parscale=20))
>
>
>
> Error in fn(par, ...) : unused argument(s) (meth = "BFGS")
>
>
>
>
>
> FYI, I am using R version 2.6.1 on Windows XP.
>
>
>
> May I ask what the rationale behind this change is and also about the pros
> and cons of the two different ways of specifying (.)?
>
>
>
> Thank you very much.
>
>
>
> Best,
>
> Ravi.
>
>
>
>
----------------------------------------------------------------------------
> -------
>
> Ravi Varadhan, Ph.D.
>
> Assistant Professor, The Center on Aging and Health
>
> Division of Geriatric Medicine and Gerontology
>
> Johns Hopkins University
>
> Ph: (410) 502-2619
>
> Fax: (410) 614-9625
>
> Email: rvaradhan at jhmi.edu
>
> Webpage:  http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html
>
>
>
>
----------------------------------------------------------------------------
> --------
>
>
>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.
>
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595