Re: [R] How to split a factor (unique identifier) into several others?

From: Dimitris Rizopoulos <dimitris.rizopoulos_at_med.kuleuven.be>
Date: Thu, 7 Feb 2008 09:20:14 +0100

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try the following:

dat <- data.frame(x = c("sample1_condition1_place1",

    "sample2_condition1_place1", "sample3_condition1_place1",     "sample1_condition2_place1", "sample1_condition2_place1"))

vals <- strsplit(as.character(dat$x), "_") as.data.frame(do.call("rbind", vals))

I hope it helps.

Best,
Dimitris



Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium

Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


> Hello,
>
> I have a data frame with a factor column, which uniquely identifies
> the observations in the data frame and it looks like this:
>
> sample1_condition1_place1
> sample2_condition1_place1
> sample3_condition1_place1
> .
> .
> .
> sample3_condition3_place3
>
> I want to turn it into three separate factor columns "sample",
> "condition" and "place".
>
> This is what I did so far:
>
> # generate a factor column for the example
> fctr<- factor(c("sample1_condition1_place1",
> "sample2_condition1_place1", "sample3_condition1_place1"))
> splitfctr <- strsplit(as.character(fctr),"_")
>
>> splitfctr
> [[1]]
> [1] "sample1" "condition1" "place1"
>
> [[2]]
> [1] "sample2" "condition1" "place1"
>
> [[3]]
> [1] "sample3" "condition1" "place1"
>
>
> Now this is all fine, but how do I make three separate factors of
> this?
> The object "splitfctr" is a list of character vectors, each
> character
> vector being composed of the words after spitting the long original
> world.
> Now I want to form new character vectors, which contain the first
> component of each list entry, then another vector for the second
> component, etc.
> I don't want to use loops, unless that's the only way to do it.I
> guess
> I have some difficulty with understanding how R indexing works...
>
> ______________________________________________
> R-help_at_r-project.org mailing list
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> PLEASE do read the posting guide
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> and provide commented, minimal, self-contained, reproducible code.
>

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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. Received on Thu 07 Feb 2008 - 08:22:00 GMT

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