# here's an example data frame
n <- 10
mydf <- data.frame(present=rnorm(n),
answer=sample(1:4, n, replace=TRUE),
 p.num=sample(1:18, n, replace=TRUE),
session=sample(1:2, n, replace=TRUE),
count=sample(1:8, n, replace=TRUE),
 type=sample(1:3, n, replace=TRUE))

# define a new variable, combo5, that represents the combination of the
five columns you specified
mydf$combo5 <- with(mydf, interaction(answer, p.num, session, count, type,
drop=TRUE))

# split the data frame according to combo5
# this gives you a list of data frames
mydf.split <- split(mydf, mydf$combo5)

# use lapply() and write.table() to write each date frame in the list to a
file
lapply(mydf.split, function(x) write.table(x,
file=as.character(x$combo5[1]), sep="\t", col.names=F, row.names=F))

Jean



On Sat, Apr 6, 2013 at 6:07 PM, Mansfield, Desmond <dcm206@exeter.ac.uk>wrote:

> Hello Everybody,
>
> I'm working with a dataframe that has 18 columns. I would like to subset
> the data in one of these columns, "present", according to combinations of
> data in six of the other columns within the data frame and then save this
> into a text file. The columns I would like to use to subset "present" are:
>
>
> * answer (1:4) [answer takes the values 1 to 4]
> *p.num (1:18)
> * session (1:2)
> * count (1:8)
> * type (1:3)
>
>
> So there are a total of 3456 possible subsetting combinations.
>
>
> At present, I have been using the following and manually changing the
> values in each line and re-running the code.
>
> input<-subset(input, answer==1)
> input.s2g<-subset(input, p.num == 1)
> input.s2g<-subset(input.s2g, session == "S2")
> input.s2g<-subset(input.s2g, count==8)
> input.s2g<-subset(input.s2g, type==1)
>
>
> write.table(s2g, file = "1_1_S2_8_1", sep = "\t", col.names = F, row.names
> = F)
>
> But this takes me hours and is obviously prone to error. There must be an
> easier way?
>
>
> Thanks for any help!
>
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>
> ______________________________________________
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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.
>

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