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 identify duplicate values in a column of matrix in R?
We can easily identify duplicate values in a matrix by using duplicated function but it does not specify that the first occurrence is also duplicated. Therefore, we need to use it with OR sign | and the argument fromLast = TRUE of duplicated function so that the first occurrence of the duplicated values will be also identified as duplicate.
Example
M1<-matrix(rpois(40,2),ncol=2) M1
Output
[,1] [,2] [1,] 3 1 [2,] 4 6 [3,] 1 0 [4,] 3 4 [5,] 3 3 [6,] 2 3 [7,] 6 4 [8,] 4 4 [9,] 3 4 [10,] 3 3 [11,] 0 4 [12,] 2 3 [13,] 3 2 [14,] 4 2 [15,] 1 4 [16,] 2 1 [17,] 2 5 [18,] 3 3 [19,] 1 6 [20,] 2 1
Example
duplicated(M1[,1])|duplicated(M1[,1],fromLast=TRUE)
Output
[1] TRUE TRUE TRUE TRUE TRUE TRUE FALSE TRUE TRUE TRUE FALSE TRUE [13] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
Example
M2<-matrix(rpois(80,5),ncol=4) M2
Output
[,1] [,2] [,3] [,4] [1,] 9 7 12 5 [2,] 7 9 3 6 [3,] 4 4 3 6 [4,] 8 0 3 4 [5,] 3 9 4 2 [6,] 6 11 4 9 [7,] 4 2 6 6 [8,] 6 1 6 6 [9,] 4 3 5 8 [10,] 6 7 5 6 [11,] 9 3 6 3 [12,] 3 7 6 3 [13,] 6 7 4 6 [14,] 9 7 4 6 [15,] 6 7 4 4 [16,] 6 10 3 4 [17,] 2 3 3 8 [18,] 4 3 13 5 [19,] 4 7 4 3 [20,] 8 1 5 5
Example
duplicated(M2[,2])|duplicated(M2[,2],fromLast=TRUE)
Output
[1] TRUE TRUE FALSE FALSE TRUE FALSE FALSE TRUE TRUE TRUE TRUE TRUE [13] TRUE TRUE TRUE FALSE TRUE TRUE TRUE TRUE
Example
duplicated(M2[,3])|duplicated(M2[,3],fromLast=TRUE)
Output
[1] FALSE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE [13] TRUE TRUE TRUE TRUE TRUE FALSE TRUE TRUE
Updated on: 07-Dec-2020
325 Views
Advertisements