wavethresh (version 4.7.3)

plot.imwd: Draw a picture of the 2D wavelet coefficients using image

Description

This function images 2D the absolute values discrete wavelet transform coefficients arising from a imwd.object object.

Usage

# S3 method for imwd
plot(x, scaling = "by.level", co.type = "abs",
	package = "R", plot.type = "mallat", arrangement = c(3, 3),
	transform = FALSE, tfunction = sqrt, ...)
# S3 method for imwdc
plot(x, verbose=FALSE, ...)

Value

If the package="S" argument is set then a matrix is returned containing the image that would have been plotted (and this only works if the plot.type="mallat" argument is set also.

Arguments

x

The 2D imwd object you wish to depict

scaling

How coefficient scaling is performed. The options are by.level to scale the coefficients independently by level, anything else causes coefficients to be scaled globally

co.type

Can be "abs" for the absolute values of the coefficients to be plotted, can be "mabs" for the negative absolute values or "none" for none of this.

package

Can be "R" for the R package, or "S". The latter does less interesting things and results in a simpler plot

plot.type

If this argument is "mallat" the coefficients at different scales and orientations are packed into one image and plotted, a format originating from Mallat's early papers on this. The other possibility is "cols" which plots each combination of scale and direction on a separate plot. This latter format is useful for examining coefficients, especially at the coarser scales.

arrangement

If plot.type="cols" then this argument specifies how many rows and columns there are in the plot array.

transform

If FALSE then the coefficients are plotted as they are (subject to the co.type argument above), if TRUE then the transform function supplied by tfunction is applied to the coefficients.

tfunction

If transform=TRUE then this function gets applied to transform the coefficients before plotting

verbose

Print out informative messages

...

Supply other arguments to the call to the image function. This is very useful to, e.g., can the colours, or other aspects of the image

Author

G P Nason

Details

Description says all

See Also

imwd, imwd.object, threshold.imwd

Examples

data(lennon)
lwd <- imwd(lennon)
if (FALSE) plot(lwd)
if (FALSE) plot(lwd, col=grey(seq(from=0, to=1, length=100)), transform=TRUE)