[R] multi-dimension array of raw

[Prof Brian Ripley]

On Tue, 20 Jun 2006, Duncan Murdoch wrote:

> On 6/20/2006 6:24 PM, Gerald Jansen wrote:
>> I would like to store and manipulate large sets of marker genotypes
>> compactly using "raw" data arrays. This works fine for vectors or
>> matrices, but I run into the error shown in the example below as soon
>> as I try to use 3 dimensional arrays (eg. animal x marker x allele).
>>
>>> a <- array(as.raw(1:6),c(2,3))
>>> a
>>      [,1] [,2] [,3]
>> [1,]   01   03   05
>> [2,]   02   04   06
>>> a[1,] <- raw(3)
>>> a
>>      [,1] [,2] [,3]
>> [1,]   00   00   00
>> [2,]   02   04   06
>>> b <- array(as.raw(1:6),c(1,2,3))
>>> b[1,,]
>>      [,1] [,2] [,3]
>> [1,]   01   03   05
>> [2,]   02   04   06
>>> b[1,1,] <- raw(3)
>> Error: incompatible types (from raw to raw) in array subset assignment
>>
>> I can work around this with computed indices, but I wonder if this is
>> expected behaviour.
>
> I don't think so.  It is just an unimplemented case.
>
> Using raw in this way is a fairly unusual thing to do, and you've come
> across a case nobody thought of implementing.

Actually, raw arrays were originally not implemented at all, so this is 
`expected behaviour', and you may well encounter other unimplemented areas 
as no one has attempted to implement them comprehensively. Please report 
them, but on R-devel not here.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595