CODEWITHSUNDEEP
rlinear-regression
coder_bg
coder_bg

Reputation: 370

How to convert categorical variable to numerical in R?

I am very new to R

I have the following dataset

age    sex    bmi children smoker    region   charges  sex_N
1  19 female 27.900        0    yes southwest 16884.924 female
2  18   male 33.770        1     no southeast  1725.552   male
3  28   male 33.000        3     no southeast  4449.462   male
4  33   male 22.705        0     no northwest 21984.471   male
5  32   male 28.880        0     no northwest  3866.855   male
6  31 female 25.740        0     no southeast  3756.622 female

I want to predict charges based on the other columns however other columns are categorical how do I change them to numeric variables?

I tried doing costs$sex_N <- as.factor(costs$sex) but that did not give me the correct column as you can see above?

also, if columns which has unique values greater than 2 , how to convert them? please help!

Upvotes: 1

Views: 1767

Answers (1)

ThomasIsCoding
ThomasIsCoding

Reputation: 101034

Here are two base R options that may help

> transform(
+   costs,
+   sex_N = as.integer(as.factor(sex_N))
+ )
  age    sex    bmi children smoker    region   charges sex_N
1  19 female 27.900        0    yes southwest 16884.924     1
2  18   male 33.770        1     no southeast  1725.552     2
3  28   male 33.000        3     no southeast  4449.462     2
4  33   male 22.705        0     no northwest 21984.471     2
5  32   male 28.880        0     no northwest  3866.855     2
6  31 female 25.740        0     no southeast  3756.622     1

or

> transform(
+   costs,
+   sex_N = match(sex_N, sex_N)
+ )
  age    sex    bmi children smoker    region   charges sex_N
1  19 female 27.900        0    yes southwest 16884.924     1
2  18   male 33.770        1     no southeast  1725.552     2
3  28   male 33.000        3     no southeast  4449.462     2
4  33   male 22.705        0     no northwest 21984.471     2
5  32   male 28.880        0     no northwest  3866.855     2
6  31 female 25.740        0     no southeast  3756.622     1

Upvotes: 2

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