CODEWITHSUNDEEP
rlistfunctiondataframe
millie0725
millie0725

Reputation: 371

How to change the name of certain elements for dataframes in a list

I have several dataframes within a list so that I can apply functions to each dataframe at once; below is some mock data

df1 <- data.frame(spp = c("Rubsp", "Rusp", "Cest", "Ceor", "Dagl"),
                 julian = c(60, 70, 80, 90, 100))
df2 <- data.frame(spp = c("Sosp", "Spsp", "Cest", "Umsp", "Dagl"),
                  julian = c(60, 70, 80, 90, 100))
df3 <- data.frame(spp = c("Syal", "Syla", "Cest", "Umsp", "Ceor"),
                  julian = c(60, 70, 80, 90, 100))

spp_list <- list(df1=df1, df2=df2, df3=df3)

I am trying to make a function to change some misspellings of certain species names within the dataframes. For example, "Rubsp" needs to be "Rusp". Below is my attempt at this function.

change_spp <- function(df){
  (df[["spp"]] == "Rubsp") -> "Rusp"
  (df[["spp"]] == "Sosp") -> "Spsp"
  (df[["spp"]] == "Syal") -> "Syla"
  return(df)
}

spp_list <- lapply(spp_list, change_spp)

When I apply this function to my list of dataframes, nothing changes. I can't figure out the right syntax to get these names to be fixed.

Using R version 4.0.2, Mac OS X 10.13.6

Upvotes: 0

Views: 40

Answers (2)

Yuriy Saraykin
Yuriy Saraykin

Reputation: 8880

use tidyverse and replacement table

library(tidyverse)

# replacement table
rplc <- data.frame(spp = c("Rubsp", "Sosp", "Syal"), spp_correct = c("Rusp", "Spsp", "Syla"))

map(spp_list, ~ left_join(.x, rplc) %>% 
      transmute(spp = coalesce(spp_correct, spp), julian))
#> Joining, by = "spp"
#> Joining, by = "spp"
#> Joining, by = "spp"
#> $df1
#>    spp julian
#> 1 Rusp     60
#> 2 Rusp     70
#> 3 Cest     80
#> 4 Ceor     90
#> 5 Dagl    100
#> 
#> $df2
#>    spp julian
#> 1 Spsp     60
#> 2 Spsp     70
#> 3 Cest     80
#> 4 Umsp     90
#> 5 Dagl    100
#> 
#> $df3
#>    spp julian
#> 1 Syla     60
#> 2 Syla     70
#> 3 Cest     80
#> 4 Umsp     90
#> 5 Ceor    100

Created on 2020-12-07 by the reprex package (v0.3.0)

Upvotes: 0

Duck
Duck

Reputation: 39595

Try this:

#Function
change_spp <- function(df){
  df$spp[df$spp== "Rubsp"] <- "Rusp"
  df$spp[df$spp== "Sosp"] <- "Spsp"
  df$spp[df$spp== "Syal"] <- "Syla"
  return(df)
}
#Apply
spp_list <- lapply(spp_list, change_spp)

Output:

spp_list
$df1
   spp julian
1 Rusp     60
2 Rusp     70
3 Cest     80
4 Ceor     90
5 Dagl    100

$df2
   spp julian
1 Spsp     60
2 Spsp     70
3 Cest     80
4 Umsp     90
5 Dagl    100

$df3
   spp julian
1 Syla     60
2 Syla     70
3 Cest     80
4 Umsp     90
5 Ceor    100

Your approach would need something like this in order to work (indexing):

#Function
change_spp <- function(df){
  df$spp[df[["spp"]] == "Rubsp"] <- "Rusp"
  df$spp[df[["spp"]] == "Sosp"] <- "Spsp"
  df$spp[df[["spp"]] == "Syal"] <- "Syla"
  return(df)
}
#Apply
spp_list2 <- lapply(spp_list, change_spp)

Same output.

Upvotes: 1

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