CODEWITHSUNDEEP
rdataframe
Atul
Atul

Reputation: 45

Convert Character column value to binary value in data frame

I have a class column in my data frame which carries the value "Bad" & "Good". I want to replace these string into 0 & 1 respectively.

I tried the following: 

 x = c("Bad", "Good", "Bad", "Bad", "Good")

factor(x)

factor(x, c(0, 1))

but, it converts the value in the dataset to NA 

factor(x, c(0, 1))

[1] <NA> <NA> <NA> <NA> <NA>`
Levels: 0 1`

Upvotes: 3

Views: 18218

Answers (2)

Hlynur
Hlynur

Reputation: 335

A convenient tidyverse approach would be to use dplyr's recode function.

df <- data.frame(x = c("Bad", "Good", "Bad", "Bad", "Good"))
df$x <- as.factor(df$x)

library(tidyverse)
df <- df %>% 
    mutate(x = recode(x, 
                      "Bad" = "0", 
                      "Good" = "1"))

That's assuming you want to keep it as a factor column. If you'd rather it be a numeric vector you'd simply add a second mutate call to convert it to numeric... EDIT: being careful to convert the values as numbers, not the underlying level codes.

df <- df %>% 
  mutate(x = recode(x, 
                    "Bad" = "0", 
                    "Good" = "1")) %>% 
  mutate(x = as.numeric(levels(x))[x])

Upvotes: 7

Damian
Damian

Reputation: 1433

You can use a named vector to map the text strings to numeric values.

df <- data.frame( x = c("Bad", "Good", "Bad", "Bad", "Good"), stringsAsFactors = FALSE)

lookup <- c("Bad" = 0, "Good" = 1)

df$new_x <- lookup[df$x]

Result

df
     x new_x
1  Bad     0
2 Good     1
3  Bad     0
4  Bad     0
5 Good     1


# showing type info
str(df)
'data.frame':   5 obs. of  2 variables:
 $ x    : chr  "Bad" "Good" "Bad" "Bad" ...
 $ new_x: num  0 1 0 0 1

Upvotes: 1

Related Questions