- Data Structure
- Networking
- RDBMS
- Operating System
- Java
- MS Excel
- iOS
- HTML
- CSS
- Android
- Python
- C Programming
- C++
- C#
- MongoDB
- MySQL
- Javascript
- PHP
- Physics
- Chemistry
- Biology
- Mathematics
- English
- Economics
- Psychology
- Social Studies
- Fashion Studies
- Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
How to find the frequency table for factor columns in an R data frame?
If we have factor columns in an R data frame then we want to find the frequency of each factor level for all the factor columns. This can be done with the help of sapply function with table function. For example, if we have a data frame called df that contains some factor columns then the frequency table for factor columns can be created by using the command sapply(df,table).
Example1
Consider the below data frame −
> x1<-sample(LETTERS[1:4],20,replace=TRUE) > x2<-sample(letters[1:4],20,replace=TRUE) > df1<-data.frame(x1,x2) > df1
Output
x1 x2 1 D a 2 D b 3 D c 4 D b 5 D c 6 C a 7 C a 8 B a 9 A a 10 C c 11 D a 12 D b 13 D b 14 A c 15 C b 16 D a 17 A b 18 A b 19 B c 20 C b
Finding the frequency table for factor columns in df1 −
> sapply(df1,table) $x1
Output
A B C D 4 2 5 9
Example
$x2
Output
a b c 7 8 5
Example2
> y1<-sample(c("India","Russia","UK"),20,replace=TRUE) > y2<-sample(c("Male","Female"),20,replace=TRUE) > df2<-data.frame(y1,y2) > df2
Output
y1 y2 1 India Male 2 UK Female 3 Russia Male 4 India Female 5 India Female 6 India Male 7 UK Female 8 Russia Male 9 UK Male 10 India Male 11 Russia Male 12 UK Male 13 UK Female 14 India Female 15 India Female 16 Russia Female 17 Russia Female 18 Russia Female 19 India Female 20 India Female
Finding the frequency table for factor columns in df2 −
> sapply(df2,table) $y1
Output
India Russia UK 9 6 5
Example
$y2
Output
Female Male 12 8
Advertisements