Convert a list in data.frame in format Longdata

Question

I Have this data.base in class list in R.

$multiinstrumentais
[1] "248269" "248827"

$geds
[1] "248198" "248198" "248857"

$ghzmb
[1] "248087" "296994" "302862"

I want to Transform in something like this in data.frame:

words - cod 
multiinstrumentais - 248269
multiinstrumentais - 248827
geds - 248198
geds - 248198
geds - 248857
ghzmb - 248087
ghzmb - 296994
ghzmb - 302862

What have you tried so far? What step are you having problems with? — Ross, Mar 02 '18 at 13:40

Val · Answer 1 · 2018-03-02T14:07:44.173

Maybe there's a more elegant way, but this will do fine:

lst<- list(
  multiinstrumentais=c("248269","248827"),
  geds=c("248198","248198","248857"),
  ghzmb=c("248087","296994","302862")
)


df <- do.call(rbind,
lapply(seq_along(lst), function(ix) data.frame(words=rep(names(lst)[ix],length(lst[[ix]])),
                                              cod=lst[[ix]]))
)

#output

# > df
# words    cod
# 1 multiinstrumentais 248269
# 2 multiinstrumentais 248827
# 3               geds 248198
# 4               geds 248198
# 5               geds 248857
# 6              ghzmb 248087
# 7              ghzmb 296994
# 8              ghzmb 302862

This uses lapply to iterate over the list elements, binding the multiple of the element name and the respective values in a dataframe together.

do.call(rbind, combines everything into a single dataframe.

tyluRp · Answer 2 · 2018-03-02T15:01:05.280

1

This can actually be done with stack from base R:

stack(lst)

  values                ind
1 248269 multiinstrumentais
2 248827 multiinstrumentais
3 248198               geds
4 248198               geds
5 248857               geds
6 248087              ghzmb
7 296994              ghzmb
8 302862              ghzmb

Here's another solution with dplyr and tibble, though this adds a number to the end of the row name, you can remove it by adding mutate(rowname = str_remove(rowname, pattern = '[[:digit:]]+')) to the chain:

library(tibble)
library(dplyr)

lst %>% 
  unlist() %>% 
  as.tibble() %>%
  rownames_to_column()

Returns:

# A tibble: 8 x 2
  rowname             value 
  <chr>               <chr> 
1 multiinstrumentais1 248269
2 multiinstrumentais2 248827
3 geds1               248198
4 geds2               248198
5 geds3               248857
6 ghzmb1              248087
7 ghzmb2              296994
8 ghzmb3              302862

Or with tidyr and dplyr, this seems to work:

lst %>% 
  unlist() %>% 
  bind_rows() %>% 
  gather()

# Alternatively, this one liner
tidyr::gather(bind_rows(unlist(lst)))

Using Val's data:

lst<- list(
  multiinstrumentais=c("248269","248827"),
  geds=c("248198","248198","248857"),
  ghzmb=c("248087","296994","302862")
)

edited Mar 02 '18 at 15:01

answered Mar 02 '18 at 13:47

tyluRp

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The one-liner is sweet! You should add the `library` call for `tidyr` though. – Val Mar 02 '18 at 14:08
Good idea, I added it :) – tyluRp Mar 02 '18 at 14:10
How to remove the numbers at end? – Gabriel Sartori Mar 02 '18 at 14:39
try `stack(lst)` – tyluRp Mar 02 '18 at 14:46
After i create , how to remove the numbers at the end???? rowname value 1 multiinstrumentais1 248269 2 multiinstrumentais2 248827 3 geds1 248198 4 geds2 248198 5 geds3 248857 6 ghzmb1 248087 7 ghzmb2 296994 8 ghzmb3 302862 – Gabriel Sartori Mar 02 '18 at 14:57
rowname value 1 multiinstrumentais1 248269 2 multiinstrumentais2 248827 3 geds1 248198 4 geds2 248198 5 geds3 248857 6 ghzmb1 248087 7 ghzmb2 296994 8 ghzmb3 302862 – Gabriel Sartori Mar 02 '18 at 14:58
`stack(lst)` should avoid the numbers at the end of the row names – tyluRp Mar 02 '18 at 14:58

Convert a list in data.frame in format Longdata

2 Answers2