How to replace “Male” into “Female”in the dataset?

Question

I have a dataset something like this:

dataset

How can I replace all the Male into Female using r?

Do not post your data as an image, please learn how to give a [reproducible example](http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example/5963610) — Jaap, Feb 26 '17 at 14:39

score 2 · Answer 1 · answered Feb 26 '17 at 14:51

First, welcome to Stackoverflow. As pointed in the comments, it's better to give a reproducible example. I'm happy to answer this time, but bear in mind that in the future, you are more likely to get answers if you give such an example.

I'm assuming you're working with a data frame. What you would need is:

> df <- data.frame("name"=c("A","B","C","D"), sex=c("Male","Male","Male","Female"))
> df
  name    sex
1    A   Male
2    B   Male
3    C   Male
4    D Female
> df$sex[df$sex == "Male"] <- "Female"
> df
  name    sex
1    A Female
2    B Female
3    C Female
4    D Female

The line df$sex[df$sex == "Male"] <- "Female" is what you are looking for. The first part, df$sex, selects the column named sex.

The second part, [df$sex == "Male"], selects all rows of the column which have sex equal to "Male".

The last part is assignment. <- "Female" assigns selected observations the value "Female".

An example of a reproducible example would be the code I gave in the answer. — wwl, Feb 26 '17 at 14:51

akrun · Answer 2 · 2017-02-26T15:50:05.827

1

We can use

library(data.table)
setDT(df)[sex=="Male", sex := "Female"]

Or using base R

df$sex <- with(df, replace(sex, sex=="Male", "Female"))

edited Feb 26 '17 at 15:50

answered Feb 26 '17 at 15:39

akrun

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This won't work if there are other values below (like "unknown"). – Rodrigo Feb 26 '17 at 15:48
@Rodrigo okay, then i corrected it – akrun Feb 26 '17 at 15:50
df$sex[df$sex == "Male"] <- "Female" is shorter. – Rodrigo Feb 26 '17 at 17:32
@Rodrigo But, that is already in the other answer – akrun Feb 26 '17 at 17:34
So, what's the point in your answer? – Rodrigo Feb 27 '17 at 03:18
@Rodrigo I am showing the `data.table` and also a `replace` way. Compact way is not always the best – akrun Feb 27 '17 at 05:04
Compact is not the best only if it's slower. Don't agree with using an external library to do what base already does, but it's good to learn a function like replace. Thank you! – Rodrigo Feb 27 '17 at 13:29

How to replace “Male” into “Female”in the dataset?

2 Answers2