ram2ffcode {ff}R Documentation

Factor codings

Description

Function ram2ffcode creates the internal factor codes used by ff to store factor levels. Function ram2ramcode is a compatibility function used instead if RETURN_FF==FALSE.

Usage

ram2ffcode(value, levels, vmode)
ram2ramcode(value, levels)

Arguments

value factor or character vector of values
levels character vector of factor levels
vmode one of the integer vmodes in .rammode

Details

Factors stored in unsigned vmodes .vunsigned have their first level represented as 0L instead of 1L.

Value

A vector of integer values representing the correspnding factor levels.

Author(s)

Jens Oehlschlägel

See Also

factor, levels.ff, vmode

Examples

 ram2ffcode(letters, letters, vmode="byte")
 ram2ffcode(letters, letters, vmode="ubyte")
 ram2ffcode(letters, letters, vmode="nibble")
 cat('note that ram2ffcode() does NOT warn that vmode="nibble" cannot store 26 levels\n')

[Package ff version 2.0.0 Index]