[R] minimum from matrix
oarabile at stams.strath.ac.uk
Tue May 8 17:41:25 CEST 2007
Thanks it worked.
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.
>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.
>>R-help at stat.math.ethz.ch mailing list
>>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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