R help - Jan 2009 - How do I find the index for a value in an array

Hello,
Could anybody tell me how to find the index for a value which I define in an
array?

ie.

c<-matrix(1:9,1,9)  #A 1x9 matrix filled with numbers 1 - 9 in order
I want to know the index for the value 5. 

Thanks in advance,

George Chen

Dear George,
Try this:

mat<-matrix(1:9,1,9)
which(mat==5,arr.ind=TRUE)
     row col
[1,]   1   5


HTH,

Jorge



On Sun, Jan 4, 2009 at 1:21 AM, George Chen <glchen@stanford.edu> wrote:
> Hello,
> Could anybody tell me how to find the index for a value which I define in
> an array?
>
> ie.
>
> c<-matrix(1:9,1,9)  #A 1x9 matrix filled with numbers 1 - 9 in order
> I want to know the index for the value 5.
>
> Thanks in advance,
>
> George Chen
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> 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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