[R] Recursive indexing failed at level 2

[Jim Hargreaves]

Hi Duncan, list,

Thanks for the advice, but unfortunately that wasn't what was causing my 
problem. I'm still getting the "Recursive indexing failed at level 2" 
message even after replacing my unlist(pulse[i]) with pulse[[i]].

Error:

 > 
pulse_subset[[1:as.numeric(length(pulse[[i]][as.numeric(peak_start[i]):as.numeric(peak_end[i])]))]] 
<- pulse[[i]][as.numeric(peak_start[i]):as.numeric(peak_end[i])]
Error in 
pulse_subset[[1:as.numeric(length(pulse[[i]][as.numeric(peak_start[i]):as.numeric(peak_end[i])]))]] 
<- pulse[[i]][as.numeric(peak_start[i]):as.numeric(peak_end[i])] :
   recursive indexing failed at level 2

It's almost as if the length of pulse[[i]] is too small, but it's length 
is 1001 and peak_start[i] and peak_end[i] are 192 and 208 respectively.

Also why would the problem crop up only after 200,000 runs?

Bizarre!

Regards,
Jim Hargreaves



On 06/26/2010 01:38 PM, Duncan Murdoch wrote:
> On 26/06/2010 8:29 AM, Jim Hargreaves wrote:
>> 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. 
> But that could not be correct.  Take a look at length(pulse[i]).  
> Assuming that i is a scalar value, length(pulse[i]) will be 1.  You 
> really do want pulse[[i]].   You used unlist(pulse[i]) which is 
> sometimes the same as pulse[[i]], but it really depends on what 
> pulse[[i]] is.  unlist() is a very crude tool, and you should avoid it 
> unless you really need it.
>
>
>> 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.
>
> Whoever told you that was mistaken.
>
> Duncan Murdoch
>> 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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>>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>>> PLEASE do read the posting guide 
>>>> http://www.R-project.org/posting-guide.html
>>>> and provide commented, minimal, self-contained, reproducible code.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide 
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>