dfCount: Count number of rows per group

In anilchalisey/juggleR: A mix of useful R functions

Description

Count how many times each distinct value of a data.frame column is observed.

Usage

dfCount(df, col, sort = TRUE, name = "total")

Arguments

df	A data.frame.
col	The column to count.
sort	Whether or not to sort the resulting total column.
name	The name of the total column.

Details

dfCount(x, "y") is similar in functionality to table(x$y), but performs better on large datasets. There are two main differences between dfCount and table: 1. dfCount returns a data.frame instead of table object 2. dfCount includes a row for number of NA observations, whereas table does not by default

Value

A data.frame with two columns: The first column is the distinct values of the given variable, the second column shows the total number of rows with that value.

Performance

This function performs much faster than its equivalent table call on large datasets, even though the table function does not sort the results. The main speed boost is due to the fact that 'dplyr' is used.

Note

The dplyr package is required for this function.

Examples

flights <- nycflights13::flights
dfCount(flights, "dest")
dfCount(flights, "dest", sort = FALSE)
dfCount(flights, "dest", name = "flights")

dfCount(infert, "education")
dfCount(infert, "education", sort = FALSE)
data.frame(table(infert$education))

anilchalisey/juggleR documentation built on May 9, 2019, 4 a.m.