CODEWITHSUNDEEP
rfrequency
user9292
user9292

Reputation: 1145

Number of times a character appears in a variable with R

I've a data frame, and one of the variables (w1) is a factor with seven levels. Here are the first few lines:

X   number          delta1 tossc w1
1   0.743477269         0   1   <NA>
2   0.742817675         0   1    x1
3   0.867432987         0   1    x5
4   0.535971961         1   1    Group3
5   0.743477269         0   1    x2
6   0.742817675         0   1    x1
7   0.867432987         0   1    <NA>
8   0.535971961         1   1   Group3 or Group4

How can find number of times each character has appeared in w1? (for example, x1 appeard 2 times, x5 appeared 1 time, etc.). Any help will be appreciated.

Upvotes: 0

Views: 198

Answers (2)

ping
ping

Reputation: 1336

An alternative would be:

length(which(dat$w1=="x1"))

which can be easily saved as a new variable.

Upvotes: 0

agstudy
agstudy

Reputation: 121578

Here a solution using merge and table

merge(dat,as.data.frame(table(dat$w1)),by.x='w1',by.y='Var1')
                w1 X    number delta1 tossc Freq
1             <NA> 1 0.7434773      0     1    2
2             <NA> 7 0.8674330      0     1    2
3           Group3 4 0.5359720      1     1    1
4 Group3 or Group4 8 0.5359720      1     1    1
5               x1 2 0.7428177      0     1    2
6               x1 6 0.7428177      0     1    2
7               x2 5 0.7434773      0     1    1
8               x5 3 0.8674330      0     1    1

Upvotes: 2

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