From rvaradhan at jhmi.edu  Thu Apr 19 20:39:20 2012
From: rvaradhan at jhmi.edu (Ravi Varadhan)
Date: Thu, 19 Apr 2012 18:39:20 +0000
Subject: [Rd] Column(row)wise minimum and maximum
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Oliver,

It is mainly a speed issue (and also compactness!), at least for me.  Using `apply' is so much slower.   I agree with you that having column and row operations available for "basic" stats operations in "base" would be great.

David - I am aware of capabilities in other packages, but I am hoping that such basic operations would be part of "base" distribution.  

Ravi

-----Original Message-----
From: oliver [mailto:oliver at first.in-berlin.de] 
Sent: Thursday, April 19, 2012 2:34 PM
To: Ravi Varadhan
Cc: r-devel at r-project.org
Subject: Re: [Rd] Column(row)wise minimum and maximum

On Thu, Apr 19, 2012 at 08:31:56PM +0200, oliver wrote:
> On Thu, Apr 19, 2012 at 06:12:30PM +0000, Ravi Varadhan wrote:
> > Hi,
> > 
> > Currently, the "base" has colSums, colMeans.  It seems that it would 
> > be useful to extend this to also include colMin, colMax (of course, 
> > rowMin and rowMax, as well) in order to facilitate faster 
> > computations for large vectors (compared to using apply).  Has this 
> > been considered before?  Please forgive me if this has already been discussed before.
> [...]
> 
> Not sure if the performance of apply is so much of a problem, but also 
> from a view of consistency of the provided functions, I think offering 
> such functions would make it more clear and consitent to use R here, 
> because all those functions are then available for row and col and the 
> functionality is appended in the name (Mean, Sum etc.).
> 
> I think the basic things that should be available woud be:
> 
>  - mean
>  - median
>  - min
>  - max
>  - var
>  - sd
   - sum   :-)
   - diff


Ciao,
   Oliver


[Rd] Column(row)wise minimum and maximum
Ravi Varadhan