Count the number of occurences.
Equivalent to as.data.frame(table(x)), but does not include
combinations with zero counts.
count(df, vars = NULL, wt_var = NULL)
df |
data frame to be processed |
vars |
variables to count unique values of |
wt_var |
optional variable to weight by - if this is non-NULL, count will sum up the value of this variable for each combination of id variables. |
Speed-wise count is competitive with table for single
variables, but it really comes into its own when summarising multiple
dimensions because it only counts combinations that actually occur in the
data.
Compared to table + as.data.frame, count
also preserves the type of the identifier variables, instead of converting
them to characters/factors.
a data frame with label and freq columns
table for related functionality in the base package
# Count of each value of "id" in the first 100 cases
count(baseball[1:100,], vars = "id")
# Count of ids, weighted by their "g" loading
count(baseball[1:100,], vars = "id", wt_var = "g")
count(baseball, "id", "ab")
count(baseball, "lg")
# How many stints do players do?
count(baseball, "stint")
# Count of times each player appeared in each of the years they played
count(baseball[1:100,], c("id", "year"))
# Count of counts
count(count(baseball[1:100,], c("id", "year")), "id", "freq")
count(count(baseball, c("id", "year")), "freq")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.