CODEWITHSUNDEEP
rvariables
Pirate
Pirate

Reputation: 321

How to count multiple numerical variables in a column in R without installing a package?

I'd like to count the number of recurring numerical variables in a given column. My data set is: mydata

And I have a dataframe that looks like this:

mydata <- structure(list(VARIABLE = c(1, 1, 2, 3, 3, 3, 4, 4)), 
  .Names = "VARIABLE",   row.names = c(NA, -8L), class = "data.frame")

mydata
##     VARIABLE
## 1        1
## 2        1
## 3        2
## 4        3
## 5        3
## 6        3
## 7        4
## 8        4

I'd like to calculate the number of 1s,2s,3s,4s in column VARIABLE (Two 1, One 2, Three 3, Two 4). Is there anyway I can do this without installing an additional package?

Upvotes: 0

Views: 1448

Answers (2)

flodel
flodel

Reputation: 89057

Yes, use table as follows, it comes from the base package:

mydata <- data.frame(VARIABLE = c(1, 1, 2, 3, 3, 3, 4, 4))
table(mydata$VARIABLE)

# 1 2 3 4 
# 2 1 3 2

As suggested by Maiasaura, you can turn the output into a nice data.frame:

data.frame(table(mydata$VARIABLE))
#   Var1 Freq
# 1    1    2
# 2    2    1
# 3    3    3
# 4    4    2

Upvotes: 4

thelatemail
thelatemail

Reputation: 93813

As an alternative to ?table you could also use ?rle in the instance of wanting to detect "runs" of particular repeating values in a variable/vector. In this instance, you will get the same results as using the table function, though this is not always the case.

mydata <- data.frame(VARIABLE = c(1, 1, 2, 3, 3, 3, 4, 4))
rle(mydata$VARIABLE)

Result:

Run Length Encoding
  lengths: int [1:4] 2 1 3 2
  values : num [1:4] 1 2 3 4

You can subset the results of the rle function as well, like so:

rle(mydata$VARIABLE)$values
[1] 1 2 3 4

rle(mydata$VARIABLE)$lengths
[1] 2 1 3 2

Upvotes: 0

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