# [R] creating cubes

Richard M. Heiberger rmh at temple.edu
Sat Jan 16 01:09:26 CET 2016

```## I think you should look at the abind ## array bind
## function in the abind package.

install.packages("abind")
library(abind)
? abind
## the examples are comprehensive

## It allows constructions like these
w <- matrix(1:6, 2, 3, dimnames=list(letters[1:2], LETTERS[3:5]))
x <- w+10
y <- w+20
z <- w+30
wxyz <- abind(W=w, X=x, Y=y, Z=z, along=.5)
dim(wxyz)
wxyz
wxyz["W", , ]

## Rich

On Fri, Jan 15, 2016 at 5:57 PM, Matteo Richiardi
<matteo.richiardi at gmail.com> wrote:
> Hi Daniel,
> thanks for your answer. How can I populate the array with the
> matrixes? Suppose I want to populate it with 10 matrixes
>
> matrix(NA,5,5)
>
> Matteo
>
>
> On 15 January 2016 at 22:26, Dalthorp, Daniel <ddalthorp at usgs.gov> wrote:
>> How about: D<-array(dim=c(d1, d2, d3))?
>>
>>
>>
>> On Fri, Jan 15, 2016 at 2:20 PM, Matteo Richiardi
>> <matteo.richiardi at gmail.com> wrote:
>>>
>>> What is the best way to store data in a cube? That is, I need to create a
>>> data structure D with three indexes, say i,j,h, so that I can access each
>>> data point D[i,j,h], and visualise sections like D[i,j,] or D[,,h].
>>>
>>> I have tried to create an array of matrixes:
>>>
>>> D <-matrix(matrix(NA,i,j),h)
>>>
>>> but then D[i] returns a number, and not a matrix.
>>>
>>> I imagine this is a dummy question, but I did search for an answer on
>>> various R help sites, and found nothing straightforward. Being an
>>> inexperienced R user, I prefer a simple solution, even at some efficiency
>>> cost.
>>>
>>> Many thanks for your help.
>>> Matteo
>>>
>>>         [[alternative HTML version deleted]]
>>>
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>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>>
>>
>> --
>> Dan Dalthorp, PhD
>> USGS Forest and Rangeland Ecosystem Science Center
>> Forest Sciences Lab, Rm 189
>> 3200 SW Jefferson Way
>> Corvallis, OR 97331
>> ph: 541-750-0953
>> ddalthorp at usgs.gov
>>
>
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