[Rd] Column(row)wise minimum and maximum

[Henrik Bengtsson]

This is why the matrixStats package was created, cf.
http://cran.r-project.org/web/packages/matrixStats/

1. Yes, it would be nice to have them in one of the default packages.
2. We decided to focus on/constrain ourselves matrices in matrixStats.
 We decided not to go into arrays with length(dim(.)) >= 3.

/Henrik

On Thu, Apr 19, 2012 at 11:39 AM, Ravi Varadhan <rvaradhan at jhmi.edu> wrote:
> 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
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