ffbase (version 0.6-2)

within.ffdf: 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 future methods.

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})