[R] Don't collapse degenerate array indices

[David Winsemius]

On Apr 19, 2012, at 9:38 AM, Sebastian Schubert wrote:

> On 19/04/12 15:25, Duncan Murdoch wrote:
>> On 19/04/2012 9:14 AM, Sebastian Schubert wrote:
>>> Hi,
>>>
>>> I want to prohibit the automatic collapsing of degenerate array  
>>> indices:
>>>
>>>> str( array(1,dim=c(3,4,5,1,1)) )
>>>  num [1:3, 1:4, 1:5, 1, 1] 1 1 1 1 1 1 1 1 1 1 ...
>>>> str( array(1,dim=c(3,4,5,1,1))[2:3,1:3,4:5,,] )
>>>  num [1:2, 1:3, 1:2] 1 1 1 1 1 1 1 1 1 1 ...
>>>
>>> The last command removed the degenerate indices. I don't want  
>>> that. What
>>> can I do?
>>
>> Use "drop=FALSE".  See ?"[".
>
> Thanks a lot for the fast help, Duncan and David! Also thanks for the
> hint of how to get help for [. I tried ?[ which did not work.

Try instead ?'['

The quoting with "?" is also needed for other functions such as dyadic  
math Ops and %in% as well as for some Control function such as 'if'  
and 'break'.


-- 

David Winsemius, MD
West Hartford, CT