[R] transposing a matrix - row by row?

ONKELINX, Thierry Thierry.ONKELINX at inbo.be
Thu Apr 23 16:40:04 CEST 2009

Dear Dimitri,

Have a look at melt() from the reshape package.




ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics,
methodology and quality assurance
Gaverstraat 4
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tel. + 32 54/436 185
Thierry.Onkelinx op inbo.be 

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-----Oorspronkelijk bericht-----
Van: r-help-bounces op r-project.org [mailto:r-help-bounces op r-project.org]
Namens Dimitri Liakhovitski
Verzonden: donderdag 23 april 2009 16:31
Aan: R-Help List
Onderwerp: [R] transposing a matrix - row by row?

I have a matrix that is a product of tapply on a larger data set.
Let's assume it looks like this:


   1   2   3
1 10 30 50
2 20 40 60

Is there an efficient way of transforming this matrix into the following

rows columns entries
1          1          10
1          2          30
1          3          50
2          1          20
2          2          40
2          3          60

Thank you very much!
Dimitri Liakhovitski
MarketTools, Inc.
Dimitri.Liakhovitski op markettools.com

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