ffbase (version 0.6-2)

with.ffdf: Evaluate an expression in a ffdf data environment

Description

Evaluate an R expression in an environment constructed from a ffdf data frame. (see with). Please note that you should write your expression as if it is a normal data.frame. The resulting return value however will be a ff object.

Usage

## S3 method for class 'ffdf':
with(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

• if expression is a vector a newly created ff vector will be returned otherwise if the expression is a data.frame a newly created ffdf object will be returned.

See Also

ffdfwith

Examples

dat <- data.frame(x=1:10, y=10:1)

ffdat <- as.ffdf(dat)

with(ffdat, {x+y})