Home Prevent the list number to appear in column names after do.call("cbind.data.frame", my_list)

Questions

Prevent the list number to appear in column names after do.call("cbind.data.frame", my_list)

June 29, 2023

I often use do.call("cbind.data.frame", my_list) after a lapply() call and usually I face no problems. For some reason in the following list the column names are different after binding them; the list number preceeds the names.

My list is something like this:

dput(my_list)

list(`1` = structure(list(`Pulmonary_embolism~f.20002.0` = NA, 
`Pulmonary_embolism~f.20002.1` = NA, `Pulmonary_embolism~f.20002.2` = NA, 
`Pulmonary_embolism~f.20002.3` = NA, `Pulmonary_embolism~f.20002.all` = NA), row.names = "1", class = "data.frame"), 
`2` = structure(list(`Pulmonary_embolism~f.6152.0` = NA, 
    `Pulmonary_embolism~f.6152.1` = NA, `Pulmonary_embolism~f.6152.2` = NA, 
    `Pulmonary_embolism~f.6152.3` = NA, `Pulmonary_embolism~f.6152.all` = NA), row.names = "1", class = "data.frame"))

But after do.call("cbind.data.frame", my_list) the variables change:

names(do.call("cbind.data.frame", my_list))

[1] "1.Pulmonary_embolism~f.20002.0"   "1.Pulmonary_embolism~f.20002.1"   "1.Pulmonary_embolism~f.20002.2"   "1.Pulmonary_embolism~f.20002.3"   "1.Pulmonary_embolism~f.20002.all"
[6] "2.Pulmonary_embolism~f.6152.0"    "2.Pulmonary_embolism~f.6152.1"    "2.Pulmonary_embolism~f.6152.2"    "2.Pulmonary_embolism~f.6152.3"    "2.Pulmonary_embolism~f.6152.all"

How to prevent the list number beeing part of the column name?

>Solution :

First you could extract the column names using lapply with unlist and make sure you use use.names=FALSE to remove the names of the dataframes in the names of the column. After that you can use these names to your do.call output like this:

your_names = unlist(lapply(my_list, \(x) colnames(x)), use.names = FALSE)
df = do.call("cbind.data.frame", my_list)
names(df) = your_names
df
#>   Pulmonary_embolism~f.20002.0 Pulmonary_embolism~f.20002.1
#> 1                           NA                           NA
#>   Pulmonary_embolism~f.20002.2 Pulmonary_embolism~f.20002.3
#> 1                           NA                           NA
#>   Pulmonary_embolism~f.20002.all Pulmonary_embolism~f.6152.0
#> 1                             NA                          NA
#>   Pulmonary_embolism~f.6152.1 Pulmonary_embolism~f.6152.2
#> 1                          NA                          NA
#>   Pulmonary_embolism~f.6152.3 Pulmonary_embolism~f.6152.all
#> 1                          NA                            NA

Another option could be using bind_cols from dplyr to not have the numbers in the names like this:

library(dplyr)

bind_cols(my_list)
#>   Pulmonary_embolism~f.20002.0 Pulmonary_embolism~f.20002.1
#> 1                           NA                           NA
#>   Pulmonary_embolism~f.20002.2 Pulmonary_embolism~f.20002.3
#> 1                           NA                           NA
#>   Pulmonary_embolism~f.20002.all Pulmonary_embolism~f.6152.0
#> 1                             NA                          NA
#>   Pulmonary_embolism~f.6152.1 Pulmonary_embolism~f.6152.2
#> 1                          NA                          NA
#>   Pulmonary_embolism~f.6152.3 Pulmonary_embolism~f.6152.all
#> 1                          NA                            NA

^{Created on 2023-06-29 with reprex v2.0.2}