使用多个条件的 r 数据帧中的分隔因子和字符列

Question

I would like to separate only two types of a column of the data frame (factors and characters) and the following codes results in an error. I wonder what is the correct way to carry out this task.

install.packages("dslabs")
library(dslabs)
data(murders)

names(murders)[sapply(murders, (is.factor | is.character))]

I can use the following code to combine the two, but I wonder what will be the correct format in case I want to use multiple conditions as the code above.

c(names(murders)[sapply(murders, is.factor)],names(murders)[sapply(murders, is.character)])

Answer 1

We may need a lambda function

names(murders)[sapply(murders, function(x) 
      is.factor(x) | is.character(x))]

Or another option is to get the class and use %in%

names(murders)[sapply(murders, class) %in% c("factor", "character")]

Or with Filter

names(Filter(function(x) is.factor(x)|is.character(x), murders))

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Or using tidyverse

library(dplyr)
murders %>%
    select(where(~ is.factor(.x)|is.character(.x))) %>%
    names