plot.imwd

Plot 2D wavelet transform coefficients.

DESCRIPTION

USAGE

plot.imwd(imwd, scaling = "by.level", co.type = "abs", package = "SPlus", 
    plot.type = "mallat", arrangement = c(3, 3), transform = F, 
    tfunction = sqrt) 

REQUIRED ARGUMENTS

imwd

The imwd object whose coefficients you wish to plot.

OPTIONAL ARGUMENTS

scaling

If "by.level" then each orientation gets an individual rescaling to 0 to 255 on each scale. If anything else then each scale gets scale stretched to 0 to 255 but on a scale by scale basis (Actually, it would have been better if "by.level" had been renamed "by.orientation").

co.type

If "abs" then the absolute values of the coefficients are plotted. If "mabs" then the negative absolute values of the coefficients are plotted.

package

If "SPlus" then a plot is drawn on the current graphics device. If "S" then the values that would have been drawn on the plot are returned as a matrix. You could then plot these values using another call to, e.g. image. The "S" option is especially useful for the R package as the matrix of the image that would have been plotted is returned and then one is free to plot this image in R (e.g. setting colormap options in image() with e.g.

	col=grey(seq(from=0, to=1, length=255))
	

to get a grey scale picture, or using other graphics devices.)

plot.type

If "mallat" then the coefficients are arranged as a montage of subimages that occupy no more space than the original image (illustrating the space efficiency of the wavelet transform). If "cols" then the subimages are plotted on multiple pages. This option can be useful when you want to view the coarse scale images at a decent size. With the Mallat mosaic the coarse scale images are sometimes very small.

arrangement

If plot.type="cols" then this parameter sets the mfrow parameter for the par command issued just before the plot. So, if you wanted your coefficient subimages displayed in a 4x4 panel set arrangement=c(4,4).

transform

If T a transform is applied to the coefficients after their absolute value, or negative absolute values have been computed. If F then no transform is applied.

tfunc

If transform=T then this argument specifies the function to use to transform the absolute coefficients before plotting.

VALUE

SIDE EFFECTS

DETAILS

RELEASE

SEE ALSO

EXAMPLES

# The help to threshold.imwd shows the
# plot.imwd function in action.