[R] What is the matrix version of min()

[Tong Wang]

Hi, 
   THANK YOU ALL for the prompt reply. 

cheers.

----- Original Message -----
From: Robin Hankin <r.hankin at noc.soton.ac.uk>
Date: Wednesday, September 6, 2006 1:42 am
Subject: Re: [R] What is the matrix version of min()
To: Tong Wang <wangtong at usc.edu>
Cc: R help <r-help at stat.math.ethz.ch>

> Tong
> 
> you need to use apply().  The second argument specifies whether
> you want to work with rows or columns.  The point of this is that
> min() and max() operate on vectors and give a single value,
> and you want to "apply" this function to all rows or all columns:
> 
> > a <- matrix(rnorm(30),5,6)
> > apply(a,2,max)
> [1] 2.6413241 0.9842076 1.7989560 0.6999855 2.0542201 0.1162821
> > apply(a,1,max)
> [1] 1.1771370 0.9811693 2.6413241 0.9842076 2.0542201
> >
> 
> HTH
> 
> rksh
> 
> 
> On 6 Sep 2006, at 09:37, Tong Wang wrote:
> 
> > Hi,
> >     Is there a function which operates on a matrix and return a  
> > vector of min/max of each rol/col ?
> > say,  X=  2,  1
> >                 3,  4
> > min.col(X)=c(2,1)
> >
> > thanks a lot.
> >
> > tong
> >
> > ______________________________________________
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> 
> > guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> 
> --
> Robin Hankin
> Uncertainty Analyst
> National Oceanography Centre, Southampton
> European Way, Southampton SO14 3ZH, UK
>  tel  023-8059-7743
> 
> 
> 
> 
>