2

I use str_locate_all to get the start and end positions of a list of patterns in my string. It returns a list with the start and stop position for each match. How can I get the start and stop positions of all matches into separate lists? 

library(stringr)

patterns <- c("ABS", "BSDF", "ERIDF", "RTZOP")
string <- "ABSBSDFERIDFRTZOPABSBSDFRTZOPABSBSDFERIDFRTZOP"

matches <- str_locate_all(string, patterns)

Result:

[[1]]
      start end
[1,]     1   3
[2,]    18  20
[3,]    30  32

[[2]]
       start end
[1,]     4   7
[2,]    21  24
[3,]    33  36

[[3]]
       start end
[1,]     8  12
[2,]    37  41

[[4]]
       start end
[1,]    13  17
[2,]    25  29
[3,]    42  46

What I would like:

start <- c(1, 18, 30, 4, 21, 33, 8, 37, 13, 25, 42)
end <- c(3, 20, 32, 7, 24, 36, 12, 41, 17, 29, 46)
Nivel
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1 Answers1

3

Use do.call with rbind to stack the lists together, then take out the desired columns.

> library(stringr)
> 
> patterns <- c("ABS", "BSDF", "ERIDF", "RTZOP")
> string <- "ABSBSDFERIDFRTZOPABSBSDFRTZOPABSBSDFERIDFRTZOP"
> 
> matches <- str_locate_all(string, patterns)
> 
> all <- do.call(rbind, matches)
> start <- all[, 1]
> stop <- all[, 2]
> start
 [1]  1 18 30  4 21 33  8 37 13 25 42
> stop
 [1]  3 20 32  7 24 36 12 41 17 29 46
Joseph Clark McIntyre
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