![Trending Articles on Technical and Non Technical topics](/images/trending_categories.jpeg)
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 unique permutations if a vector contains repeated elements in R?
We can use permn function from combinat package to find the permutations but if we have repeated elements in the vector then the result will not have unique permutations, therefore, we need to use unique function along with the permn function. For example, if we have a vector 1, 2, 1 then the permutations will be (1 2 1), (1 1 2), (1 1 2), (1 2 1), (2 1 1), (2 1 1) and the unique permutations will be (1 2 1), (1 1 2), (2 1 1).
Example
x1<-c(1,2,1,2) x1
Output
[1] 1 2 1 2
Finding all permutations −
permn(x1)
[[1]] [1] 1 2 1 2 [[2]] [1] 1 2 2 1 [[3]] [1] 1 2 2 1 [[4]] [1] 2 1 2 1 [[5]] [1] 2 1 1 2 [[6]] [1] 1 2 1 2 [[7]] [1] 1 1 2 2 [[8]] [1] 1 1 2 2 [[9]] [1] 1 1 2 2 [[10]] [1] 1 1 2 2 [[11]] [1] 1 2 1 2 [[12]] [1] 2 1 1 2 [[13]] [1] 2 1 2 1 [[14]] [1] 1 2 2 1 [[15]] [1] 1 2 2 1 [[16]] [1] 1 2 1 2 [[17]] [1] 2 1 1 2 [[18]] [1] 2 1 2 1 [[19]] [1] 2 2 1 1 [[20]] [1] 2 2 1 1 [[21]] [1] 2 2 1 1 [[22]] [1] 2 2 1 1 [[23]] [1] 2 1 2 1 [[24]] [1] 2 1 1 2
Finding the unique permutations −
unique(permn(x1))
[[1]] [1] 1 2 1 2 [[2]] [1] 1 2 2 1 [[3]] [1] 2 1 2 1 [[4]] [1] 2 1 1 2 [[5]] [1] 1 1 2 2 [[6]] [1] 2 2 1 1
Example
x2<-c(0,1,0) permn(x2)
[[1]] [1] 0 1 0 [[2]] [1] 0 0 1 [[3]] [1] 0 0 1 [[4]] [1] 0 1 0 [[5]] [1] 1 0 0 [[6]] [1] 1 0 0
unique(permn(x2))
[[1]] [1] 0 1 0 [[2]] [1] 0 0 1 [[3]] [1] 1 0 0
Advertisements