# cumsum in 3d arrays

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## cumsum in 3d arrays

 Hello! Is it posible to apply cumsum() along the 3rd dimension of 3D array? Something like matrlab function - cumsum (A,dim) which returns the cumulative sum of the elements along the dimension of A specified by scalar dim. Thanks in advance Željka
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## Re: cumsum in 3d arrays

 zloncaric biologija.unios.hr> writes: > Is it posible to apply /cumsum()/ along the 3rd dimension of 3D array? > Something like matrlab function - /cumsum (*A*,dim)/ which returns the > cumulative sum of the elements along the dimension of *A* specified by > scalar dim.   Check out the combination of apply and cumsum. ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: cumsum in 3d arrays

 In reply to this post by zloncaric On Nov 26, 2011, at 9:32 AM, zloncaric wrote: > Hello! > > Is it posible to apply /cumsum()/ along the 3rd dimension of 3D array? > Something like matrlab function - /cumsum (*A*,dim)/ which returns the > cumulative sum of the elements along the dimension of *A* specified by > scalar dim. > `apply` lets you chose which dimension gets selected. Perhaps: apply(mat, 3, cumsum) (This is pretty basic stuff so you should probably be reading or at   least skimming somewhat more thoroughly than you have so far the   Introduction to R document and there is also the R for Matlab document   by Bob Muenchen ... and a compendium of equivalencies by Hiebeler at: www.math.umaine.edu/~hiebeler/comp/matlabR.html   ) -- David Winsemius, MD West Hartford, CT ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: cumsum in 3d arrays

 On Nov 26, 2011, at 11:24 AM, David Winsemius wrote: > > On Nov 26, 2011, at 9:32 AM, zloncaric wrote: > >> Hello! >> >> Is it posible to apply /cumsum()/ along the 3rd dimension of 3D   >> array? >> Something like matrlab function - /cumsum (*A*,dim)/ which returns   >> the >> cumulative sum of the elements along the dimension of *A* specified   >> by >> scalar dim. >> > > `apply` lets you chose which dimension gets selected. > > Perhaps: > > apply(mat, 3, cumsum) Or perhaps   apply(mat, 1:2, cumsum) > > (This is pretty basic stuff so you should probably be reading or at   > least skimming somewhat more thoroughly than you have so far the   > Introduction to R document and there is also the R for Matlab   > document by Bob Muenchen ... and a compendium of equivalencies by   > Hiebeler at: www.math.umaine.edu/~hiebeler/comp/matlabR.html ) > > -- David Winsemius, MD West Hartford, CT ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: cumsum in 3d arrays

 Thank you for your time and help. I'm quite aware that this problem seems as basic stuff, and of course I've read several R and matlab manuals, and also consulted the D. Hiebeler, Matlab / R Reference and several others, but none of the suggested solutions seems to give me the right result. I've tried the combination of apply and cumsum but the result is wrong.
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## Re: cumsum in 3d arrays

 Hi: Could you supply a small reproducible example with the output that you expect? For example, what output would you expect from the following: a <- array(1:24, c(2, 2, 3)) ? Dennis On Mon, Nov 28, 2011 at 12:32 AM, zloncaric <[hidden email]> wrote: > Thank you for your time and help. > > I'm quite aware that this problem seems as basic stuff, and of course I've > read several R and matlab manuals, and also consulted the D. Hiebeler, > Matlab / R Reference and several others, but none of the suggested solutions > seems to give me the right result. > I've tried the combination of apply and cumsum but the result is wrong. > > > > > > -- > View this message in context: http://r.789695.n4.nabble.com/cumsum-in-3d-arrays-tp4110470p4114510.html> Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > [hidden email] 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. > ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.