CODEWITHSUNDEEP
rdplyr
John Davis
John Davis

Reputation: 303

Frequency table using dplyr package

I am very new to R.I want to create a new frequency column based on a particular column.

City    age
ABC     47
AAB     48
AAB     41
AAB     984
ZZZ     984
MNO      1
MNO     34
VVC     34
VVC     36
VVC     41
VVC     32
MNO     20
BB      29
VVC     4
VVC    984
VVC     59
ABC     30
ABC    984
ABC     36
BB      69
ABC     32
ZZZ     3
ABC     29
ABC     29
AAB     1
AAB     984
ABC     59

I want data frame looks like -

City    age     Frequency
ABC     47      0.296296296
AAB     48      0.185185185
AAB     41      0.185185185
AAB     984     0.185185185
ZZZ     984     0.074074074
MNO     1       0.111111111
MNO     34      0.111111111
VVC     34      0.259259259
VVC     36      0.259259259
VVC     41      0.259259259
VVC     32      0.259259259
MNO     20      0.111111111
BB      29      0.074074074
VVC     4       0.259259259
VVC     984     0.259259259
VVC     59      0.259259259
ABC     30      0.296296296
ABC     984     0.296296296
ABC     36      0.296296296
BB      69      0.074074074
ABC     32      0.296296296
ZZZ     3       0.074074074
ABC     29      0.296296296
ABC     29      0.296296296
AAB     1       0.185185185
AAB     984     0.185185185
ABC     59      0.296296296

In frequency column, I used this formula -

ABC   8             0.296296296 (8/27)
MNO   3             0.111111111 (3/27)
BB    2             0.074074074 (2/27)
VVC   7             0.259259259 (7/27)
ZZZ   2             0.074074074 (2/27)
AAB   5             0.185185185 (5/27)

You can ignore 'Age' column. How to do it in R?

Thanks in advance.

Regards, John

Upvotes: 1

Views: 4063

Answers (1)

akrun
akrun

Reputation: 887821

After grouping by 'City', create the 'Frequency' by dividing the number of rows (n()) with the number of rows of the whole dataset

library(dplyr)
df1 %>%
    group_by(City) %>%
    mutate(Frequency = n()/nrow(.))

Upvotes: 3

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