Count number of occurences for each unique value

Question

Count number of occurences for each unique value

Let's say I have:

v = rep(c(1,2, 2, 2), 25)

Now, I want to count the number of times each unique value appears. unique(v) returns what the unique values are, but not how many they are.

> unique(v)

[1] 1 2

I want something that gives me

length(v[v==1])

[1] 25

length(v[v==2])

[1] 75

but as a more general one-liner :) Something close (but not quite) like this:

#<doesn't work right> length(v[v==unique(v)])

unique count r-language

4 years ago by Kajalsi45d

2 Answers

Login / Signup to Answer the Question.

Login Signup

**vishaljlf39** · Answer 1 · 2021-08-06T11:33:55

Perhaps table is what you are after?

dummyData = rep(c(1,2, 2, 2), 25)



table(dummyData)

# dummyData

#  1  2 

# 25 75



## or another presentation of the same data

as.data.frame(table(dummyData))

#    dummyData Freq

#  1         1   25

#  2         2   75

**sandhya6gczb** · Answer 2 · 2021-08-09T06:35:09

If you have multiple factors (= a multi-dimensional data frame), you can use the dplyr package to count unique values in each combination of factors:



library("dplyr")

data %>% group_by(factor1, factor2) %>% summarize(count=n())

It uses the pipe operator %>% to chain method calls on the data frame data.

C TUTORIAL

C PROGRAMS

INTERVIEW TESTS

EXECUTE CODE

C++ TUTORIAL

C++ PROGRAMS

INTERVIEW TESTS

EXECUTE CODE

PYTHON TUTORIAL

PYTHON HOW TOS

INTERVIEW TESTS

EXECUTE CODE

JAVA TUTORIAL

JAVA CODE EXAMPLES

SPRING TUTORIAL

MORE IN JAVA

COMPUTER ARCHITECTURE

COMPUTER NETWORK

OPERATING SYSTEM

DBMS & SQL

PL/SQL

MongoDB

EXECUTE SQL

ANDROID DEVELOPMENT

GO LANGUAGE

LINUX

DOCKER

HTML TAGS (A to Z)

CSS REFERENCES

SASS/SCSS

KOTLIN

GAME DEVELOPMENT

PHP

GIT GUIDE

JAVASCRIPT

ADVANCED DSA

Count number of occurences for each unique value

2 Answers

Login / Signup to Answer the Question.