Combining lists with do.call while preserving each entry of the list on a row

Question

Forgive me if this has been asked before...

I have multiple lists that I wish to combine as follows

A <- list(c("R", "L", "*", "T", "M", "S", "S", "S", "S", "Y"), 
  c("G", "A", "G", "P", "P", "V", "P"), 
  c("E", "G", "R", "E", "Q", "T", "K", "G", "S", "G"), 
  c("Y", "N", "N", "D", "W"), 
  c("T", "K"))

B <- list(c("G", "T", "Q", "R"), 
  c("T", "G", "L", "W", "D", "Y", "*", "L", "Q", "H", "A", "P", "H", "L", "H", "L"), 
  c("E", "E", "D", "A", "G", "G", "R", "E", "D", "S", "I", "L", "V", "N", "G", "A", "T", "P", "\"", "\"", "C", "S", "D", "Q", "S", "S", "D", "S", "P", "P", "I", "L", "E", "A", "I", "R"), 
  c("S", "M", "C", "G", "*", "I", "K", "P"), 
  c("D", "S", "P"))

C <- list(c("G", "L", "V", "L", "A", "H", "L", "R", "R", "L", "G"), 
  c("G", "S", "D", "T", "P", "V", "M", "P", "K", "L", "F"), 
  c("N", "W", "F", "E", "N", "T", "F", "D", "F", "R", "N", "K", "R", "C", "K", "*", "V"), 
  c("P", "A", "T", "R", "S", "L", "R", "R", "R", "A", "T", "A"), 
  c("I", "G", "F", "I", "P", "S", "P", "L", "R"))

What I want is this:

A           B                                       C
RL*TMSSSSY  GTQR                                    GLVLAHLRRLG
GAGPPVP     TGLWDY*LQHAPHLHL                        GSDTPVMPKLF 
EGREQTKGSG  EEDAGGREDSILVNGATP""CSDQSSDSPPILEAIR    NWFENTFDFRNKRCK*V
YNNDW       SMCG*IKP                                PATRSLRRRATA
TK          DSP                                     IGFIPSPLR

I've tried the following but this puts every character of the list on a different row equating to different number of rows for each list:

do.call(cbind, list(A,B,C))

Is there a way to get what I want?

Thx

score 1 · Accepted Answer · answered Apr 26 '17 at 20:18

1

If you want to use tidyverse functions, you could do

library(tidyverse)
lst(A,B,C) %>% map_df(map_chr, paste, collapse="")

The lst() function allows use to make a list and keep the variable names. Then we map() over the the columns and, within each column, map() over the list of character vectors and collapse them.

answered Apr 26 '17 at 20:18

MrFlick

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Nice approach. I earlier tried with nested maps, but somehow couldn't get it worked. – akrun Apr 26 '17 at 20:49

akrun · Answer 2 · 2017-04-26T19:59:07.927

0

We can do this with a nested sapply to loop over the list

 m1 <- sapply(list(A, B, C), function(x) sapply(x, paste, collapse=""))
 setNames(as.data.frame(m1), LETTERS[1:3])

edited Apr 26 '17 at 19:59

answered Apr 26 '17 at 19:53

akrun

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score 0 · Answer 3 · edited May 23 '17 at 12:34

Here is one base R method.

data.frame(do.call(mapply,
                   list(function(x) sapply(x, paste, collapse=""), list(A=A, B=B, C=C))))

This returns

           A                                    B                 C
1 RL*TMSSSSY                                 GTQR       GLVLAHLRRLG
2    GAGPPVP                     TGLWDY*LQHAPHLHL       GSDTPVMPKLF
3 EGREQTKGSG EEDAGGREDSILVNGATP""CSDQSSDSPPILEAIR NWFENTFDFRNKRCK*V
4      YNNDW                             SMCG*IKP      PATRSLRRRATA
5         TK                                  DSP         IGFIPSPLR

Here, do.call applies Map. The list in the second line are the arguments for Map which applies sapply over the a named list of the lists. sapply pastes the vectors of each list item and returns a vector.

Notes:

this is an attempt at replicating methods alexis-laz showed me earlier here.
I originally used Map, but mapply appears to be roughly 33% faster (344ms vs. 513ms) according to microbenchmark.

Combining lists with do.call while preserving each entry of the list on a row

3 Answers3