# [R] minimum from matrix

Oarabile Molaodi oarabile at stams.strath.ac.uk
Tue May 8 17:42:16 CEST 2007

```Thanks it worked

Oarabile

Dimitris Rizopoulos wrote:

> try this:
>
> apply(a, 2, function(x) min(x[x > 0]))
>
>
> I hope it helps.
>
> Best,
> Dimitris
>
> ----
> Dimitris Rizopoulos
> Ph.D. Student
> Biostatistical Centre
> School of Public Health
> Catholic University of Leuven
>
> Address: Kapucijnenvoer 35, Leuven, Belgium
> Tel: +32/(0)16/336899
> Fax: +32/(0)16/337015
> Web: http://med.kuleuven.be/biostat/
>     http://www.student.kuleuven.be/~m0390867/dimitris.htm
>
>
> ----- Original Message ----- From: <oarabile at stams.strath.ac.uk>
> To: <r-help at stat.math.ethz.ch>
> Sent: Tuesday, May 08, 2007 10:50 AM
> Subject: [R] minimum from matrix
>
>
>>
>>
>> I have a very large matrix with columns that have some of their
>> entries as zero
>>
>>
>> A small example if a=
>>
>>         [,1]  [,2]  [,3]  [,4]
>>     [,1] 0     2     0     0
>>     [,2] 1     3     0     3
>>     [,3] 2     0     3     5
>>     [,4] 0     4     0     0
>>
>> and what to get the minimum number from each column but that number
>> should not be zero. If I use apply (a,2,min) I will get a vector of
>> zeros as the minimum but what I want it for example from column 1 I
>> should get 1 i.e for all the matrix I should get a vector (1,2,3,3). I
>> wonder if someone can give an idea on how to go about it.
>>
>>
>> Oarabile
>>
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