phonTools (version 0.2-2.1)

vplot: Plot Vowels

Description

A flexible function that can create a wide variety of vowel plots (including IPA symbols).

Usage

vplot (x, y, labels = NULL, colors = NULL, points = NULL, 
meansonly = FALSE, ellipsesd = 0, add = FALSE, alternateaxes = FALSE,
xsampa = FALSE, logaxes = FALSE, ...)

Arguments

x

A numeric vector indicating formant frequencies to be plotted on the x axis.

y

A numeric vector indicating formant frequencies to be plotted on the y axis.

labels

A vector with labels for vowels. Must be provided for any category-dependent differences in plotting. If x-sampa labels are given IPA symbols may be plotted.

colors

Colors to use for different categories. If specified this overrides automatic colors. It cycles through the list given if number of colors are less than number of categories.

points

Kinds of points to use determined by 'pch' value. If specified it overrides text labels. IPA symbols may be plotted by finding appropriate values using the pickIPA() function included in this package.

meansonly

If TRUE, only category means are plotted (labels must be provided).

ellipsesd

If a number greater than zero is given, ellipses are drawn enclosing this many standard deviations (one per category as indicated by label vector).

add

If TRUE, vowels are plotted on existing figure. If FALSE, a new one is created.

logaxes

Linear axes are used by default, for log axes set to TRUE.

alternateaxes

If TRUE, the origin in the top right corner of the plot, resulting in a configuration like the IPA vowel quadrilateral if F1 and F2 are provided. By default the origin in the bottom left corner.

xsampa

If TRUE, the labels vector given to the function is assumed to be specified in x-sampa and IPA symbols are used to plot using the xsampatoIPA() function included in this package. If this is set to TRUE and the 'labels' input is not in x-sampa, the symbols will be wrong.

...

Additional arguments are passed to the internal call of 'plot'.

Author

Santiago Barreda <[e-mail]>

Details

*** This function replaces the older vowelplot() function, which has been deprecated. ***

A flexible vowel plotting function, including functionality to easily generate vowel plots using IPA symbols. This relies on category labels being specified in x-sampa (the required plotting values for IPA symbols may be selected using the pickIPA() function included in this package).

Default parameter values are set for the plot, but these may all be overridden using the standard plotting parameters.

There may be issues when exporting figures to PDF using IPA font. Exporting plots directly as images works 'out of the box'.

References

http://en.wikipedia.org/wiki/X-SAMPA

Examples

## A few examples of some vowel plots. 

## load the Peterson and Barney data
data (pb52)
pb52 = pb52[pb52$type=='m',]  ## use only the males

par (mfrow = c(3,2), mar = c(4.2,4.2,1,1))

# standard layout with linear axes
vplot (pb52$f1, pb52$f2, pb52$vowel, xsampa = TRUE)

# alternate layout with log axes
vplot (pb52$f1, pb52$f2, pb52$vowel, logaxes = TRUE, 
           alternateaxes = TRUE, xsampa = TRUE)

# category means only 
vplot (pb52$f1, pb52$f2, pb52$vowel, logaxes = TRUE, 
           meansonly = TRUE, xsampa = TRUE, cex = 3)

# category means only with standard deviation ellipses
vplot (pb52$f1, pb52$f2, pb52$vowel, logaxes = FALSE, 
       meansonly = TRUE, ellipsesd = 2, xsampa = TRUE)

# same as above, with alternate axes
vplot (pb52$f1, pb52$f2, pb52$vowel, logaxes = TRUE, 
       meansonly = TRUE, ellipsesd = 2, xsampa = TRUE, 
	   alternateaxes = TRUE)

# individual points with standard deviation ellipses
# and alternate axes
vplot (pb52$f1, pb52$f2, pb52$vowel, logaxes = TRUE, 
	   meansonly = FALSE, ellipsesd = 2, xsampa = TRUE, 
	   alternateaxes = TRUE)