Convert a numeric column to binary factor based on a condition in R data frame

To convert a numeric column to binary factor based on a condition in R data frame, we can use factor function along with ifelse function.

For Example, if we have a data frame called df that contains a numerical column say Num and we want to convert it to a binary factor if Num is less than 100 then it will be Minor otherwise Major then we can use the below given command −

df$Num_Factor<-factor(ifelse(df$Num_Factor<100,"Minor","Major"))

Example 1

Following snippet creates a sample data frame −

x<-sample(1:50,20) df1<-data.frame(x) df1

The following dataframe is created

 x 1 4 2 13 3 50 4 19 5 43 6 42 7 18 8 17 9 27 10 23 11 31 12 37 13 5 14 28 15 1 16 6 17 30 18 35 19 22 20 10

To convert x into a factor column on the above created data frame, add the following code to the above snippet −

x<-sample(1:50,20) df1<-data.frame(x) df1$x_Factor<-factor(ifelse(df1$x<25,"Low","High")) df1

Output

If you execute all the above given snippets as a single program, it generates the following Output −

 x x_Factor 1 4 Low 2 13 Low 3 50 High 4 19 Low 5 43 High 6 42 High 7 18 Low  8 17 Low  9 27 High 10 23 Low 11 31 High 12 37 High 13 5 Low 14 28 High 15 1 Low 16 6 Low 17 30 High 18 35 High 19 22 Low 20 10 Low

Example 2

Following snippet creates a sample data frame −

y<-round(rnorm(20,1,0.25),1) df2<-data.frame(y) df2

The following dataframe is created

 y 1 1.4 2 0.9 3 1.0 4 0.6 5 1.1 6 0.7 7 0.9 8 1.2 9 0.8 10 1.1 11 0.7 12 0.4 13 1.1 14 0.8 15 1.1 16 0.7 17 1.7 18 0.8 19 1.1 20 0.6

To convert y into a factor column on the above created data frame, add the following code to the above snippet −

y<-round(rnorm(20,1,0.25),1) df2<-data.frame(y) df2$y_Factor<-factor(ifelse(df2$y<1,"Rejected","Accepted")) df2

Output

If you execute all the above given snippets as a single program, it generates the following Output −

 y y_Factor 1 1.4 Accepted 2 0.9 Rejected 3 1.0 Accepted 4 0.6 Rejected 5 1.1 Accepted 6 0.7 Rejected 7 0.9 Rejected 8 1.2 Accepted 9 0.8 Rejected 10 1.1 Accepted 11 0.7 Rejected 12 0.4 Rejected 13 1.1 Accepted 14 0.8 Rejected 15 1.1 Accepted 16 0.7 Rejected 17 1.7 Accepted 18 0.8 Rejected 19 1.1 Accepted 20 0.6 Rejected