[R] Split a data.frame

K. Elo m@illi@t@ @ending from pp@inet@fi
Sat May 19 17:25:41 CEST 2018


Hi!

How about this:

--- snip --

for (i in 1:(length(split_str)-1)) {
    assign(paste("DF",i,sep=""),DF[
c((which(DF$name==split_str[i])+1):(which(DF$name==split_str[i+1])-1)), 
])
}

--- snip ---

'assign' creates for each subset a new data.frame DFn, where n ist a
count (1,2,...).

But note: if your DF has duplicates in 'name' (e.g. two rows with 'a'
in 'DF$name'), my solution will use the first occurrence only (and this
for both start and for end).

HTH,
Kimmo

2018-05-19 kello 16:37 +0530, Christofer Bogaso wrote:
> Hi,
> 
> I am struggling to split a data.frame as will below scheme :
> 
> DF = data.frame(name = c('a', 'v', 'c'), val = 0); DF
> 
> split_str = c('a', 'c')
> 
> Now, for each element in split_str, R should find which row of DF
> contains
> that element, and return DF with all rows starting from next row of
> the
> corresponding element and ending with the preceding value of the next
> element.
> 
> So in my case, I should see 2 data.frames
> 
> 1st data-frame with name = 'v' (i.e. 2nd row of DF)
> 
> 2nd data.frame with number_of_rows as 0 (as there is no row left
> after 'c')
> 
> Similarly if split_str = c('v'') then, my 2 data.frames will be
> 
> 1st data.frame with name = 'a'
> 2nd data.frame with name = 'c'
> 
> Any idea how to efficiently implement above scheme would be highly
> appreciated. I tried with split() function, however, it is not giving
> the
> right answer.
> 
> Thanks,
> 
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