[R] minimum of each row in a matrix

Schmitt, Corinna Corinna.Schmitt at igb.fraunhofer.de
Tue May 8 15:21:26 CEST 2007


Hallo,

I just followed the discussion of the title: minimum from matrix.
I have a similar problem.

> a=matrix(c(0,2, 0, 0, 1, 3, 0, 3, 2, 0, 3, 5, 0, 4, 0, 0),ncol=4)
> a=rbind(a,1:4)
> a
     [,1] [,2] [,3] [,4]
[1,]    0    1    2    0
[2,]    2    3    0    4
[3,]    0    0    3    0
[4,]    0    3    5    0
[5,]    1    2    3    4
>
> minOfColumns=apply(a, 2, function(x) min(x[x!=0]) )
> minOfColumns
[1] 1 1 2 4
> maxOfColumns=apply(a, 2, function(x) max(x) )
> maxOfColumns
[1] 2 3 5 4
>

How looks like the command for the minimum of the rows? I tried several
possibilities with apply but did not get the wanted result. The result
should be minOfRows = 0 0 0 0 1

Thanks,
Corinna



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