count of entries in data frame in R

user_220602 0
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I'm looking to get a count for the following data frame:

> Santa
   Believe Age Gender Presents Behaviour
1    FALSE   9   male       25   naughty
2     TRUE   5   male       20      nice
3     TRUE   4 female       30      nice
4     TRUE   4   male       34   naughty

of the number of children who believe. What command would I use to get this?

(The actual data frame is much bigger. I've just given you the first four rows...)

Thanks!

dataframe count r
7 Answers

A one-line solution with data.table could be

library(data.table)
setDT(x)[,.N,by=Believe]
   Believe N
1:   FALSE 1
2:    TRUE 3
user_43633150

using sqldf fits here:

library(sqldf)
sqldf("SELECT Believe, Count(1) as N FROM Santa
       GROUP BY Believe")
user_37688710
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