plot.wst2D: Plot packet-ordered 2D non-decimated wavelet coefficients.

Description

This function plots packet-ordered 2D non-decimated wavelet coefficients arising from a wst2D object.

Usage

# S3 method for wst2D
plot(x, plot.type="level", main="", ...)

Value

A plot of the coefficients contained within the wst2D object is produced.

Arguments

x: The wst2D object whose coefficients you wish to plot.
plot.type: So far the only valid argument is "level" which plots coefficients a level at a time.
main: The main title of the plot.
...: Any other arguments.

RELEASE

Version 3.9 Copyright Guy Nason 1998

Author

G P Nason

Details

The coefficients in a wst2D object are stored in a three-dimensional subarray called wst2D. The first index of the 3D array indexes the resolution level of coefficients: this function with plot.type="level" causes an image of coefficients to be plotted one for each resolution level.

The following corresponds to images produced on S+ graphics devices (e.g. image on motif()). Given a resolution level there are 4^(nlevelsWT-level) packets within a level. Each packet can be addressed by a base-4 string of length nlevels-level. A zero corresponds to no shift, a 1 to a horizontal shift, a 2 to a vertical shift and a 3 to both a horizontal and vertical shift.

So, for examples, at resolution level nlevelsWT-1 there are 4 sub-images each containing 4 sub-images. The main subimages correspond to (clockwise from bottom-left) no shift, horizontal shift, both shift and vertical shifts. The sub-images of the sub-images correspond to the usual smooth, horizontal detail, diagonal detail and vertical detail (clockwise, again from bottom left). Coarser resolution levels correspond to finer shifts! The following figure demonstrates the nlevels-1 resolution level for the ua image (although the whole image has been rotated by 90 degrees clockwise for display here!):

Examples

Run this code

#
# The above picture is one of a series produced by 
#
#plot(uawst2D)
#
# Where the uawst2D object was produced in the EXAMPLES section
# of the help for \code{\link{wst2D}}

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