Split data.frame row into multiple rows based on commas

Question

I am attempting to split a row in a data.frame based on the character sequence \", \". Here\'s an example:

mydat <- data.frame(v1 = c(\"name,         


        

Answer 1

This should work.

install.packages("splitstackshape")
library(splitstackshape)
out <- concat.split.multiple(mydat, c("v1","v2"), seps=",", "long")


out
     v1 v2 v3
1:  name  1  1
2: name2  2  1
3: name3  3  2
4: name4  4  3
5: name5  5  3

Answer 2

For posterity, users with an inclination for tidyverse packages can use tidyr's separate_rows function along with select from dplyr (to maintain the order of the columns) to get this done:

library(tidyverse)

mydat %>% separate_rows(v1,v2,sep=", ") %>% 
        select(v1, v2, v3)

#     v1 v2 v3
#1  name  1  1
#2 name2  2  1
#3 name3  3  2
#4 name4  4  3
#5 name5  5  3

Answer 3

Here's another way using data.table package and its new tstrsplit function

library(data.table) # v >= 1.9.5
setDT(mydat)[, lapply(.SD, tstrsplit, ", "), by = v3]
#    v3    v1 v2
# 1:  1  name  1
# 2:  1 name2  2
# 3:  2 name3  3
# 4:  3 name4  4
# 5:  3 name5  5