I have the following data:
PassengerId Survived Pclass Sex Age SibSp Parch Fare Embarked
1 1 0 3 male 22 1 0 7.2500 S
2 2 1 1 female 38 1 0 71.2833 C
3 3 1 3 female 26 0 0 7.9250 S
4 4 1 1 female 35 1 0 53.1000 S
5 5 0 3 male 35 0 0 8.0500 S
6 6 0 3 male NA 0 0 8.4583 Q
Now, when I use the dummy or dummy.data.frame, I can successfully convert factors (here Sex and Embarked)to dummies like this:
PassengerId Survived Pclass Sexfemale Sexmale Age SibSp Parch Fare Embarked EmbarkedC EmbarkedQ EmbarkedS
1 1 0 3 0 1 22 1 0 7.2500 0 0 0 1
2 2 1 1 1 0 38 1 0 71.2833 0 1 0 0
3 3 1 3 1 0 26 0 0 7.9250 0 0 0 1
4 4 1 1 1 0 35 1 0 53.1000 0 0 0 1
5 5 0 3 0 1 35 0 0 8.0500 0 0 0 1
6 6 0 3 0 1 NA 0 0 8.4583 0 0 1 0
Now, if how can I apply this on Age column where it's creating more than 100 dummies, one for each unique age entry and one for NA. I want the output to be like
Age Age.NA
22 0
38 0
......
35 0
0 1
It is automatically treating missing values as a different entry and creating a variable for it in case of factors, but I want to achieve the same in case of numeric variables without hampering already existing values in the column. Please help.
You can just use:
df$Age.NA <- ifelse(is.na(df$Age), 1, 0)
And then:
library(dummies)
dummy.data.frame(df)
Output:
PassengerId Survived Pclass Sexfemale Sexmale Age SibSp Parch Fare EmbarkedC EmbarkedQ EmbarkedS Age.NA
1 1 0 3 0 1 22 1 0 7.2500 0 0 1 0
2 2 1 1 1 0 38 1 0 71.2833 1 0 0 0
3 3 1 3 1 0 26 0 0 7.9250 0 0 1 0
4 4 1 1 1 0 35 1 0 53.1000 0 0 1 0
5 5 0 3 0 1 35 0 0 8.0500 0 0 1 0
6 6 0 3 0 1 NA 0 0 8.4583 0 1 0 1
Data:
df <- structure(list(PassengerId = 1:6, Survived = c(0L, 1L, 1L, 1L,
0L, 0L), Pclass = c(3L, 1L, 3L, 1L, 3L, 3L), Sex = structure(c(2L,
1L, 1L, 1L, 2L, 2L), .Label = c("female", "male"), class = "factor"),
Age = c(22L, 38L, 26L, 35L, 35L, NA), SibSp = c(1L, 1L, 0L,
1L, 0L, 0L), Parch = c(0L, 0L, 0L, 0L, 0L, 0L), Fare = c(7.25,
71.2833, 7.925, 53.1, 8.05, 8.4583), Embarked = structure(c(3L,
1L, 3L, 3L, 3L, 2L), .Label = c("C", "Q", "S"), class = "factor"),
Age.NA = c(0, 0, 0, 0, 0, 1)), .Names = c("PassengerId",
"Survived", "Pclass", "Sex", "Age", "SibSp", "Parch", "Fare",
"Embarked", "Age.NA"), row.names = c("1", "2", "3", "4", "5",
"6"), class = "data.frame")