R: Evaluate an expression in a ffdf data environment

within.ffdf {ffbase}

R Documentation

Evaluate an expression in a ffdf data environment

Description

Same functionality as within. Please note that you should write your expression as if it is a normal data.frame. The resulting data.frame however will be a new ffdf data.frame.

Usage

## S3 method for class 'ffdf'
within(data, expr, ...)

Arguments

`data`	`ffdf` data object used as an environment for evaluation.
`expr`	expression to evaluate.
`...`	arguments to be passed to `chunk`.

Value

a modified clone of data.

Examples


ffdat <- as.ffdf(data.frame(x=1:10, y=10:1))
# add z to the ffdat
within(ffdat, {z <- x+y})

[Package ffbase version 0.12.8 Index]