[R] Reshaping an array - how does it work in R

[Jeff Newmiller]

R always makes a copy for this kind of operation. There are some operations that don't make copies, but I don't think this one qualifies. 

-- 
Sent from my phone. Please excuse my brevity.

On March 18, 2016 2:28:35 PM PDT, Roy Mendelssohn - NOAA Federal <roy.mendelssohn at noaa.gov> wrote:
>Hi All:
>
>I am working with a very large array.  if noLat is the number of
>latitudes, noLon the number of longitudes and noTime the number of 
>time periods, the array is of the form:
>
>myData[noLat, no Lon, noTime].
>
>It is read in this way because that is how it is stored in a (series)
>of netcdf files.  For the analysis I need to do, I need instead the
>array:
>
>myData[noLat*noLon, noTime].  Normally this would be easy:
>
>myData<- array(myData,dim=c(noLat*noLon,noTime))
>
>My question is how does this command work in R - does it make a copy of
>the existing array, with different indices for the dimensions, or does
>it just redo the indices and leave the given array as is?  The reason
>for this question is my array is 30GB in memory, and I don’t have
>enough space to have a copy of the array in memory.  If the latter I
>will have to figure out a work around to bring in only part of the data
>at a time and put it into the proper locations.
>
>Thanks,
>
>-Roy
>
>
>
>**********************
>"The contents of this message do not reflect any position of the U.S.
>Government or NOAA."
>**********************
>Roy Mendelssohn
>Supervisory Operations Research Analyst
>NOAA/NMFS
>Environmental Research Division
>Southwest Fisheries Science Center
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>
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>
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