# [R] problems to report indexes when I have two min value

jim holtman jholtman at gmail.com
Fri Sep 16 19:37:19 CEST 2011

Will this work for you:

>  dat <-
+ matrix(c(5.4,4.8,5.6,4.8,NA,4.4,4.6,3.4,NA,NA,4,2.4,NA,NA,NA,2),byrow=TRUE,ncol=4)
> k <- apply(dat, 1, function(x) which(x == min(x, na.rm = TRUE)))
> k
[[1]]
[1] 2 4

[[2]]
[1] 4

[[3]]
[1] 4

[[4]]
[1] 4

> sapply(k, paste, collapse = ', ')
[1] "2, 4" "4"    "4"    "4"
>

On Fri, Sep 16, 2011 at 12:26 PM, marlene marchena
<marchenamarlene at gmail.com> wrote:
> Sorry, maybe I was not clear in what I want. I need the two indexes.
>
> k
> 2 4
> 4
> 4
> 4
>
> Marlene
>
> 2011/9/16 Jean-Christophe BOUĖTTÉ <jcbouette at gmail.com>
>
>> Hi there,
>> Assuming you would prefer to have only one min per row:
>>
>> apply(dat,1,which.min)
>>
>> there is a link to this function in the help page for ?min.
>> JC
>>
>> 2011/9/16 marlene marchena <marchenamarlene at gmail.com>:
>> > Hi,
>> >
>> > I need to repor the index of a min value of each row in a matrix, but I
>> > don't know how to do that when I have more than one min value.
>> >
>> > Here is my example
>> >
>> >> dat <-
>> >
>> matrix(c(5.4,4.8,5.6,4.8,NA,4.4,4.6,3.4,NA,NA,4,2.4,NA,NA,NA,2),byrow=TRUE,ncol=4)
>> >
>> >> dat
>> >     [,1] [,2] [,3] [,4]
>> > [1,]  5.4  4.8  5.6  4.8
>> > [2,]   NA  4.4  4.6  3.4
>> > [3,]   NA   NA  4.0  2.4
>> > [4,]   NA   NA   NA  2.0
>> >> k <- apply(dat, 1, function(x) which(x == min(x, na.rm = TRUE)))
>> >>    k
>> > [[1]]
>> > [1] 2 4
>> >
>> > [[2]]
>> > [1] 4
>> >
>> > [[3]]
>> > [1] 4
>> >
>> > [[4]]
>> > [1] 4
>> >
>> > But I need an output like this
>> >
>> > k<- 2 or 4, 4, 4, 4
>> >
>> > Someone could help me with this issue.
>> >
>> >
>> > Marlene.
>> >
>> >        [[alternative HTML version deleted]]
>> >
>> > ______________________________________________
>> > R-help at r-project.org mailing list
>> > https://stat.ethz.ch/mailman/listinfo/r-help
>> http://www.R-project.org/posting-guide.html
>> > and provide commented, minimal, self-contained, reproducible code.
>> >
>>
>
>        [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> and provide commented, minimal, self-contained, reproducible code.
>
>

--
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?