[R] Array dimnames
Domenico Vistocco
vistocco at unicas.it
Sat Dec 15 19:30:44 CET 2007
Sorry, there were mistakes in variable names... (I realized only after
pressed the send button)
Domenico Vistocco wrote:
> dave mitchell wrote:
>
>> Dear all,
>> Possibly a rudimentary question, however any help is greatly appreciated. I
>> am sorting a large matrix into an array of dim(p(i),q,3). I put each entry
>> into a corresponding matrix (1 of the 3) based on some criteria. I figure
>> this will assist me in condensing code as I can loop through the 3rd
>> dimension of the array instead of generating 3 separate matrices and using
>> the same block of code 3 times. My question is how to get the colnames of
>> the 3 nested matrices in the array to match the colnames of the data
>> matrix. In other words...
>>
>>
> Denoting with array3d the array and with matrix2d the data matrix:
>
> colnames(array3d)=colnames(array3d)
>
colnames(array3d)=colnames(matrix2d)
> Otherwise, using dimnames:
> dimnames(array3d)=list(NULL,colnames(array3d),NULL)
>
dimnames(array3d)=list(NULL,colnames(matrix2d),NULL)
> You can operate using the "[" operator, that is:
> array3d[,"region",] to extract the region columns from each dimension.
>
> You obtain the same effect using the column number, i.e.
> array3d[,2,]
>
> domenico
>
>> DATA:
>> Exp region Qty Ct ...q
>> 1 S CB 3.55 2.15 .
>> 2 S TG 4.16 2.18 .
>> 3 C OO 2.36 3.65 .
>> 4 C . . .
>> . . . . .
>> . . . . .
>> . . . . .
>> p ...........................
>>
>>
>>
>> ARRAY
>> 1
>> [,1] [,2] [,3] [,4]...q
>> 1 SOME DATA WILL FILL THIS .
>> 2 . . . .
>> 3 . . . .
>> 4 . . . .
>> . . . . .
>> . . . . .
>> . . . . .
>> P(1) ...........................
>>
>> 2
>> [,1] [,2] [,3] [,4]...q
>> 1 SOME DATA WILL FILL THIS .
>> 2 . . . .
>> 3 . . . .
>> 4 . . . .
>> . . . . .
>> . . . . .
>> . . . . .
>> P(2) ...........................
>> 3
>> [,1] [,2] [,3] [,4]...q
>> 1 SOME DATA WILL FILL THIS .
>> 2 . . . .
>> 3 . . . .
>> 4 . . . .
>> . . . . .
>> . . . . .
>> . . . . .
>> P(3) ...........................
>>
>> Again, how to get those [,1], [,2]... to read (and operate) in the same
>> fashion as the column names in the data matrix? Also, am I interpreting the
>> dimensions of the array incorrectly? Please feel free to post any helpful
>> links on the subject, as I have found "dimnames" and "array" in the R-help
>> documentation unhelpful. Any help is greatly appreciated.
>>
>> Dave Mitchell
>> Undergraduate: Statistics and Mathematics,
>> University of Illinois, Urbana-Champaign
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at 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.
>>
>>
>>
>
> ______________________________________________
> R-help at 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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