How to convert gender in dataframes from integer to character using R

Question

I have a column in my dataframe where gender is coded 1 and 0 for male and female respectively. It's not a replica, but looks something like this:

df <- read.csv("df.csv")

      "  Gender   Age    Width
1          0      35      1.4   
2          0      30      1.4  
3          1      32      1.3   
4          1      31      1.5    
5          0      36      1.4  
6          1      39      1.7  "

I've managed to change the class type of it to factor and gave it labels:

df$Gender <- as.factor(df$Gender)
class(df$Gender)

df$Gender <- factor(df$Gender,
levels = c("1","0"),
labels = c("male", "female"))

However, when I try to print df$Gender, I get all "NA" as my output

UPDATE: Thank you all for your help! I realised that my code works when I run it the first time. It only becomes "NA" when I rerun the second chunk. Will this be a problem or can I just ignore it?

Please provide your data in `dput(df)` format. See [How to make a great R reproducible example](https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example). — UseR10085, Aug 31 '20 at 09:05
@BappaDas Gender = structure(c(NA_integer_, NA_integer_, NA_integer_, NA_integer_, NA_integer_, NA_integer_, .Label = c("male", "female"), class = "factor") — hellooo, Aug 31 '20 at 09:17
@BappaDas I got an error: "Error in factor(df$Gender, labels = c("male", "female")) : invalid 'labels'; length 2 should be 1 or 0" — hellooo, Aug 31 '20 at 09:20
Please provide a reproducible example of your input data. As per the description your code works fine on my computer, example input `df <- data.frame(gender = c(1L, 0L, 1L), x = 11:13)`. — s_baldur, Aug 31 '20 at 09:24

UseR10085 · Answer 1 · 2020-08-31T10:12:42.657

You can use

library(tidyverse)

df %>% 
  mutate(gender = factor(Gender, labels = c("male", "female")))

or simply

df$gender <- ifelse(df$Gender == 1,"male","female")

or

df %>% 
  mutate(gender = if_else(Gender == 1,"male","female"))

or

df %>% 
  mutate(gender = case_when(Gender == 1 ~ "male",
                            Gender == 0 ~ "female"))

Data

df = structure(list(Sn = 1:6, Gender = c(0L, 0L, 1L, 1L, 0L, 1L), 
    Age = c(35L, 30L, 32L, 31L, 36L, 39L), Width = c(1.4, 1.4, 
    1.3, 1.5, 1.4, 1.7), gender = c("female", "female", "male", 
    "male", "female", "male")), row.names = c(NA, -6L), class = "data.frame")

dholzer · Answer 2 · 2020-08-31T10:04:54.393

Everything what you have done seems correct, when I reconstruct your input

Gender <- c(1,0,1,0)
Age <- c(50,30,40,30)

df <- data.frame(Gender,Age)
df$Gender <- factor(df$Gender,
                levels = c("1","0"),
                labels = c("male", "female"))
print(df$Gender)

if you really want is as character you can then add:

df$Gender <- as.character(df$Gender)

But I think (as others already mentioned) its because of your input data, therefore try to add stringasfactors to your import command:

df <- read.csv("df.csv", stringsAsFactors = FALSE)

How to convert gender in dataframes from integer to character using R

2 Answers2