我有一个数据帧列表,其中一些列需要指定其正确的编码。所以,我创建了一个设置正确编码的函数,我想将这个新函数应用于我的数据帧列表中的特定列。我怎么能用purrr:map
做到这一点?我很新。
虚拟的例子
# Set slovak characters
Sys.setlocale(category = "LC_ALL", locale = "Slovak")
# Make a function
setEncoding<- function(x, ...) {
Encoding(x)<-"UTF-8" # set correct encoding on the vector
x # print the output
}
# Create dummy data with wrong encoding
df1<-data.frame(name = "Ľubietovský Vepor",
psb = "S CHKO PoÄľana",
numb = 1)
df2<-data.frame(name = "Goliašová",
psb = "S TANAP",
numb = 2)
list1<-list(df1, df2)
My function seems working if applied on vector string:
>setEncoding(c("Ľubietovský Vepor", "Goliašová" ))
[1] "Ľubietovský Vepor" "Goliašová"
# How to apply the whatever function (here setEncoding) on the selected columns from a dataframe list??
list1 %>%
map(setEncoding[c("name", "psb")]) # How to fix this?
我希望获得(正确编码列name
,psb
):
> ls
[[1]]
name psb numb
1 Ľubietovský Vepor S CHKO Poľana 1
[[2]]
name psb numb
1 Goliášová S TANAP 2
我不知道你想要的结果的编码细节,但我可以回答有关使用purrr
的问题。您可以使用map_if
仅将函数应用于character
向量(因为Encoding()
需要character
输入)。您的示例数据框也包含因子而不是字符串。
library(purrr)
df1<-data.frame(name = "Ľubietovský Vepor",
psb = "S CHKO PoÄľana",
numb = 1, stringsAsFactors = FALSE)
df2<-data.frame(name = "Goliašová",
psb = "S TANAP",
numb = 2, stringsAsFactors = FALSE)
list1 <- list(df1, df2) #using ls conflicts with ls() function
list1 %>%
map_if(is.character, setEncoding) #this only maps on 'name' and 'pbs'