Counting All Categorical Variables

Use for loop to count all Categorical variables in a data frame

Let’s create a sample data frame

Name <- c("John", "Max", "Nancy", "Paul", "Sandra")
Gender <- c("M","M","F","M","F")
Fav_Col <- c("Red", "Green", "Blue", "Red", "Red")
Eye_Col <- c("Brown", "Blue", "Green","Green", "Green")
Smart_Phone <- c("Apple", "Samsung", "Apple", "Apple", "Google")

data <- data.frame(Name,Gender,Fav_Col,Eye_Col,Smart_Phone)
data$Name <- as.character(data$Name)

Name <- c("John", "Max", "Nancy", "Paul", "Sandra")

Gender <- c("M","M","F","M","F")

Fav_Col <- c("Red", "Green", "Blue", "Red", "Red")

Eye_Col <- c("Brown", "Blue", "Green","Green", "Green")

Smart_Phone <- c("Apple", "Samsung", "Apple", "Apple", "Google")

data <- data.frame(Name,Gender,Fav_Col,Eye_Col,Smart_Phone)

data$Name <- as.character(data$Name)

data

data

> data
    Name Gender Fav_Col Eye_Col Smart_Phone
1   John      M     Red   Brown       Apple
2    Max      M   Green    Blue     Samsung
3  Nancy      F    Blue   Green       Apple
4   Paul      M     Red   Green       Apple
5 Sandra      F     Red   Green      Google

> data

Name Gender Fav_Col Eye_Col Smart_Phone

1 John M Red Brown Apple

2 Max M Green Blue Samsung

3 Nancy F Blue Green Apple

4 Paul M Red Green Apple

5 Sandra F Red Green Google

There are 4 Categorical variables in the data. table() can quickly count (frequency) the variables. However, we have to write table(data$column) as many times as we want to see. Let’s create a simple for loop to do the work.

for(i in names(data)) {
  if(class(data[[i]]) == "factor"){
    print(table(data[[i]]))
  }
}

for(i in names(data)) {

if(class(data[[i]]) == "factor"){

print(table(data[[i]]))

}

F M 
2 3 

 Blue Green   Red 
    1     1     3 

 Blue Brown Green 
    1     1     3 

  Apple  Google Samsung 
      3       1       1

F M

2 3

Blue Green Red

1 1 3

Blue Brown Green

1 1 3

Apple Google Samsung

3 1 1

Yep… that is quick and easy way to glance at the Categorical variables.