[R] Recursive indexing failed at level 2

[Jim Hargreaves]

On 06/26/2010 01:20 PM, Duncan Murdoch wrote:
> On 26/06/2010 7:53 AM, Jim Hargreaves wrote:
>> Dear fellow R users,
>>
>> I am replacing elements of a list like so:
>>
>> pulse_subset[[1:20]]=unlist(pulse[i])[1:20]
>
> If pulse is a list, then pulse[i] is also a list, with one element.  I 
> think you want pulse[[i]], which extracts element i.
Ahh, I specified pulse[i] has >20 values in my original mail. Basically 
pulse is a list 1000 elements long, with each element in pulse having 
between 1000 and 2000 elements of it's own. Pulse is a list of lists. 
Also as far as I am aware, [[ ]]'s should only be used when assigning 
values to elements of a list/vector.

unlist(pulse[1]) gives x1, x2, x3, x4, x5 etc. etc.
>
> If pulse_subset is a list, then pulse_subset[[1:20]] is equivalent to 
> pulse_subset[[1]][[2]][[3]][[4]] ... [[20]], i.e. the syntax implies 
> that it is a list containing a list etc, nested 20 levels deep.  The 
> error message is telling you that it's not.  I'm not sure what your 
> intention is in this case.
> Duncan Murdoch
>> where pulse is a list of lists, and pulse [i] has >20 values.
>>
>> This gives the error "Recursive Indexing failed at level 2". But, 
>> interestingly this instruction is part of a loop which has gone 
>> through about 200,000 iterations before giving this error.
>>
>> Actual code:
>> > 
>> pulse_subset[[1:(length(unlist(pulse[i])[as.numeric(peak_start[i]):as.numeric(peak_end[i])]))]] 
>> <- unlist(pulse[i])[as.numeric(peak_start[i]):as.numeric(peak_end[i])]
>>
>> Error in 
>> pulse_subset[[1:(length(unlist(pulse[i])[as.numeric(peak_start[i]):as.numeric(peak_end[i])]))]] 
>> <- unlist(pulse[i])[as.numeric(peak_start[i]):as.numeric(peak_end[i])] :
>>    recursive indexing failed at level 2
>>
>> If anyone could shed some light I'd be rather grateful.
>>
>> Regards,
>> Jim Hargreaves
>>
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>