ffbase: transform.ffdf – R documentation

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transform.ffdf

Transform a ffdf data.frame

Description

Same functionality as transform, but on a ffdf object. Please note that you should write your expression as if it is a normal data.frame. The resulting data.frame however will be a ffdf data.frame.

Usage

## S3 method for class 'ffdf'
transform(`_data`, ...)

Arguments

`_data`	`ffdf` data object to be transformed.
`...`	named arguments that will be added to the `ffdf` data.frame

Value

a modified clone of `_data`.

Examples

transform(as.ffdf(airquality), Ozone = -Ozone)
transform(as.ffdf(airquality), new = -Ozone, Temp = (Temp-32)/1.8)

ffbase

Basic Statistical Functions for Package 'ff'

v0.13.3

GPL-3

Authors

Edwin de Jonge, Jan Wijffels, Jan van der Laan

Initial release