[R] minimum from matrix

Oarabile Molaodi oarabile at stams.strath.ac.uk
Tue May 8 17:41:25 CEST 2007


Thanks it worked.
Oarabile

Gabor Csardi wrote:

>apply(a, 2, function(x) min(x[x!=0]) )
>
>should do it. Might need some improvement if all numbers in a column
>can be zero, try it.
>
>Gabor
>
>On Tue, May 08, 2007 at 09:50:43AM +0100, oarabile at stams.strath.ac.uk wrote:
>  
>
>>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.
>>
>>thanks in advance for your help.
>>
>>Oarabile
>>
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>>PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>>and provide commented, minimal, self-contained, reproducible code.
>>    
>>
>
>  
>



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