MAximum location

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MAximum location

Trying To learn again
Hi all,

I have a matrix
a<-c(2,3,4,Inf)

> b<-as.matrix(a)
     [,1]
[1,]    2
[2,]    3
[3,]    4
[4,]  Inf

> range(b, finite=TRUE)[2] (this is the maximum)
[1] 4

There is a pre-def function to extract the location (in terms of rows) of
the value in the matrix.

In my example would be

3 (max is in the third row)

The maximum is in the position (row) 3.

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Re: MAximum location

Milan Bouchet-Valat
Le jeudi 15 décembre 2011 à 21:15 +0100, Trying To learn again a écrit :

> Hi all,
>
> I have a matrix
> a<-c(2,3,4,Inf)
>
> > b<-as.matrix(a)
>      [,1]
> [1,]    2
> [2,]    3
> [3,]    4
> [4,]  Inf
>
> > range(b, finite=TRUE)[2] (this is the maximum)
> [1] 4
>
> There is a pre-def function to extract the location (in terms of rows) of
> the value in the matrix.
>
> In my example would be
>
> 3 (max is in the third row)
>
> The maximum is in the position (row) 3.
Maybe using this:
> row(b)[b == range(b, finite=TRUE)[2]]
[1] 3
> col(b)[b == range(b, finite=TRUE)[2]]
[1] 1

Not very short, since in you case involving Inf you cannot use
which.max() directly, but it works.

Regards

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