[R] Split comma separated list

[William Dunlap]

> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of Gaurav Moghe
> Sent: Tuesday, December 08, 2009 12:56 PM
> To: r-help at r-project.org
> Subject: [R] Split comma separated list
> 
> Hi all,
> 
> I'm a beginner user of R. I am stuck at what I thought was a 
> very obvious
> problem, but surprisingly, I havent found any solution on the forum or
> online till now.
> 
> My problem is simple. I have a file which has entries like 
> the following:
> #ID       Value1            List_of_values
> ID1          0.342             0.01,1.2,0,0.323,0.67
> ID2         0.010              0.987,0.056,1.3,1.5,0.4
> ID3         0.146              0.1173,0.1494,0.211,0.1257
> ...
> ...
> 
> I want to split the third column (by comma) into individual 
> values and put
> them in a variable so that I can plot a boxplot with those values, one
> boxplot per row . I have been having three issues:
> 1) R identifies the third column as an integer, instead of a 
> list of lists
> 2) I havent been able to split the third column into individual values

For 1) and 2) try:
  > z <- read.table(textConnection(input), header=T, comment="",
row.names=1, stringsAsFactors=FALSE)
  > z$List <- strsplit(z$List_of_values, ",") # strsplit fails on
factors
  > z$List <- lapply(z$List, as.numeric) # strings->numbers
  > z
       Value1             List_of_values
List
   ID1  0.342      0.01,1.2,0,0.323,0.67 0.010, 1.200, 0.000, 0.323,
0.670
   ID2  0.010    0.987,0.056,1.3,1.5,0.4 0.987, 0.056, 1.300, 1.500,
0.400
   ID3  0.146 0.1173,0.1494,0.211,0.1257    0.1173, 0.1494, 0.2110,
0.1257

> 3) How do I get it in a format suitable for plotting a boxplot?

  > boxplot(z$List, names=z$Value1)

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com 

> 
> Any suggestions? I'd really appreciate any help on this.
> 
> Thank you,
> Gaurav
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> 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.
>