How to count the number of times a value occurs in a column of an R data frame?

R ProgrammingServer Side ProgrammingProgramming

To count the number of times a value occurs in a column of an R data frame, we can use table function for that particular column.

For example, if we have a data frame called df that contains a column say Response then finding the number of times a value occurs in Response can be found by using the command given below −

table(df$Response)

Example 1

Following snippet creates a sample data frame −

x<-rpois(20,1)
df1<-data.frame(x)
df1

Output

The following dataframe is created −

   x
1  1
2  2
3  1
4  5
5  0
6  0
7  0
8  0
9  0
10 2
11 3
12 1
13 0
14 2
15 1
16 0
17 4
18 0
19 2
20 1

To create a table for data in x, add the following code to the above snippet −

x<-rpois(20,1)
df1<-data.frame(x)
table(df1$x)

Output

If you execute all the above given codes as a single program, it generates the following output −

0 1 2 3 4 5
8 5 4 1 1 1

Example 2

Following snippet creates a sample data frame −

y<-round(rnorm(20,5,2),0)
df2<-data.frame(y)
df2

Output

The following dataframe is created −

   y
1  8
2  3
3  6
4  6
5  5
6  6
7  5
8  8
9  6
10 6
11 5
12 5
13 10
14 3
15 8
16 5
17 6
18 6
19 4
20 8

To create a table for data in y, add the following code to the above snippet −

y<-round(rnorm(20,5,2),0)
df2<-data.frame(y)
table(df2$y)

Output

If you execute all the above given codes as a single program, it generates the following output −

3 4 5 6 8 10
2 1 5 7 4  1

Example 3

Following snippet creates a sample data frame −

z<-round(rnorm(20,25,1),0)
df3<-data.frame(z)
df3

Output

The following dataframe is created −

   z
1  24
2  25
3  24
4  26
5  24
6  25
7  25
8  27
9  26
10 26
11 23
12 25
13 24
14 24
15 27
16 26
17 25
18 26
19 25
20 26

To create table for data in z, add the following code to the above snippet −

z<-round(rnorm(20,25,1),0)
df3<-data.frame(z)
table(df3$z)

Output

If you execute all the above given codes as a single program, it generates the following output −

23 24 25 26 27
1   5  6 6  2
raja
Published on 06-Nov-2021 07:06:00
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