[R] How to split two levels several times?

[Rui Barradas]

Hello,

It's better if you keep this on the list, the odds of getting more and 
better answers are greater.

As for your new question, try the following.


lens <- rle(as.character(XXX$electrode))$lengths
m <- length(lens) %/% 2
idx <- rep(1:m, sapply(1:m, function(.m) sum(lens[(2*.m - 1):(2*.m)])))
split(XXX, idx)


Hope this helps,

Rui Barradas

Em 23-07-2013 11:41, dennis1991 at gmx.net escreveu:
> Hi
> this type of splitting works for my specific example. Thanks for your help.
>
> I was not absolutely clear what I generally want. I'm looking for an option that generally permits splitting two joint levels of a table after each other. For instance for the table below I want it to be divided into combinations electrode1-electrode2,  electrode3-electrode2,  electrode4-electrode1. How should I split this?
>
>
> This is the table "XXX"
>
> electrode length
>
> electrode1 5.7
> electrode1 6.3
> electrode1 6.2
> electrode2 11.4
> electrode2 9.7
> electrode3 14.2
> electrode3 14.8
> electrode3 12.6
> electrode2 11.4
> electrode2 9.7
> electrode4 17.0
> electrode4 16.3
> electrode4 17.8
> electrode4 18.3
> electrode4 16.9
> electrode4 18.5
> electrode1 5.7
> electrode1 6.3
> electrode1 6.2
>
>
>
>
>
>> Gesendet: Montag, 22. Juli 2013 um 17:53 Uhr
>> Von: "Rui Barradas" <ruipbarradas at sapo.pt>
>> An: dennis1991 at gmx.net
>> Cc: r-help at r-project.org
>> Betreff: Re: [R] How to split two levels several times?
>>
>> Hello,
>>
>> Sorry, I've just realized that your data frame is named 'XXX', not
>> 'dat'. Change that and the rest should work:
>>
>>
>> idx <- cumsum(c(TRUE, diff(XXX$electrode == "electrode1") > 0))
>> split(XXX, idx)
>>
>>
>> Rui Barradas
>>
>> Em 22-07-2013 16:47, Rui Barradas escreveu:
>>> Hello,
>>>
>>> Try the following.
>>>
>>>
>>> idx <- cumsum(c(TRUE, diff(dat$electrode == "electrode1") > 0))
>>> split(dat, idx)
>>>
>>>
>>> Hope this helps,
>>>
>>> Rui Barradas
>>>
>>> Em 22-07-2013 15:09, dennis1991 at gmx.net escreveu:
>>>> Hi,
>>>>
>>>> I have a small problem with the function split() and would appreciate
>>>> your help.
>>>>
>>>> I have a table called “XXX” with 2 columns and 49 rows. The 49 rows
>>>> belong to 8 different levels (electrode1, ...,electrode8). I want to
>>>> split the table always at the row where “electrode1” starts again so
>>>> that I can export 7  individual dataframes (numbered “dataframe1” to
>>>> ”dataframe7”) which contain always electrode1 as first level (always
>>>> three rows) with the varying number of rows for electrodes2-8 below.
>>>> I tried the split function with various setups:
>>>>
>>>> t <- as.factor(XXX$electrode)
>>>>
>>>> dataframeX <- split(XXX, f=(levels=t))
>>>>
>>>> But this doesn’t work. Could you please help. Thank you! Dennis
>>>>
>>>>
>>>> This is the table "XXX"
>>>>
>>>> electrode    length
>>>>
>>>> electrode1    5.7
>>>> electrode1    6.3
>>>> electrode1    6.2
>>>> electrode2    11.4
>>>> electrode2    9.7
>>>> electrode1    5.7
>>>> electrode1    6.3
>>>> electrode1    6.2
>>>> electrode3    14.2
>>>> electrode3    14.8
>>>> electrode3    12.6
>>>> electrode1    5.7
>>>> electrode1    6.3
>>>> electrode1    6.2
>>>> electrode4    17.0
>>>> electrode4    16.3
>>>> electrode4    17.8
>>>> electrode4    18.3
>>>> electrode4    16.9
>>>> electrode4    18.5
>>>> electrode1    ....
>>>> ....        ....
>>>> electrode5    ....
>>>> ....        ....
>>>> electrode1    ....
>>>> electrode6    ....
>>>> electrode1    ....
>>>> electrode7    ....
>>>> electrode1    ....
>>>> electrode8    ....
>>>>
>>>> ______________________________________________
>>>> 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.
>>>>
>>>
>>> ______________________________________________
>>> 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.
>>