Vowel space area functions {phonR}

Calculate the area of a vowel space

Description

Calculate the area of an F2 x F1 vowel space, either as the area of a polygon connecting vowel formant means, or the area of a convex hull encompassing all tokens.

Usage

    convexHullArea(f1, f2, group=NULL)
    vowelMeansPolygonArea(f1, f2, vowel, poly.order, group=NULL)

Arguments

f1

Numeric vector of first formant frequencies.

f2

Numeric vector or second formant frequencies.

vowel

Vector or factor of vowel identifiers (typically a character vector, though numeric will work).

poly.order

Order in which the polygon vertices should be connected. Should contain each value in vowel once.

group

Vector or factor indicating groupings of points to fit separate convex hulls to. If NULL (the default), a single hull will be generated for all points.

Author(s)

McCloy, Daniel [e-mail]

See Also

chull, areapl

Examples

    data(indoVowels)
    hull.area <- with(indo, convexHullArea(f1, f2, group=subj))
    poly.area <- with(indo, vowelMeansPolygonArea(f1, f2, vowel, 
        poly.order=c("i", "e", "a", "o", "u"), group=subj))