idata.frame: Construct an immutable data frame.

In plyr: Tools for Splitting, Applying and Combining Data

Construct an immutable data frame.

Description

An immutable data frame works like an ordinary data frame, except that when you subset it, it returns a reference to the original data frame, not a a copy. This makes subsetting substantially faster and has a big impact when you are working with large datasets with many groups.

Usage

idata.frame(df)

Arguments

df	a data frame

Details

This method is still a little experimental, so please let me know if you run into any problems.

Value

an immutable data frame

Examples

system.time(dlply(baseball, "id", nrow))
system.time(dlply(idata.frame(baseball), "id", nrow))

plyr documentation built on Oct. 2, 2023, 9:07 a.m.