rPref (version 0.3)

base_pref_macros: Useful base preference macros

Description

In addition to the fundamental base preferences, rPref offers some macros to define preferences where a given interval or point is preferred.

Usage

around(expr, center)

between(expr, left, right)

pos(expr, pos_value)

layered(expr, ...)

Arguments

expr

A numerical expression (for around and between) or an arbitrary expression (for pos and layered). We search for value where expr evaluates to a value in the preferred interval, layer, etc.

center

Preferred value for around.

left

Lower limit of the preferred interval for between.

right

Upper limit of the preferred interval for between.

pos_value

A vector containing the preferred values for a pos preference. Has to be of the same type (numeric, logical, character, ...) as expr.

...

Layers (sets) for a layered preference, where the first set are the most preferred values.

Examples

# Search for cars where mpg is near to 25
psel(mtcars, around(mpg, 25))

# cyl = 2 and cyl = 4 are equally good, cyl = 6 is worse
psel(mtcars, layered(cyl, c(2, 4), 6))