draw.imwdc {wavethresh}

Draw mother wavelet associated with an imwdc object.

Description

This function draws the mother wavelet associated with an imwdc.object — a compressed two-dimensional wavelet decomposition.

Usage

## S3 method for class 'imwdc'
draw(wd, resolution=128, ...)

Arguments

wd

The imwd class object whose associated wavelet you wish to draw. (I know its called wd, sorry).

resolution

The resolution at which the computation is done to compute the wavelet picture. Generally the resolution should be lower for two-dimensional wavelets since the number of computations is proportional to the square of the resolution (the DWT is still O(n) though).

...

Additional arguments to pass to the draw.default function which does the drawing.

Details

This function extracts the filter component from the imwd object (which is constructed using the filter.select function) to decide which wavelet to draw. Once decided the draw.default function is used to actually do the drawing.

Value

If the plot.it argument is set to TRUE then nothing is returned. Otherwise, as with draw.default, the coordinates of what would have been plotted are returned.

RELEASE

Version 2 Copyright Guy Nason 1993

Note

If the plot.it argument is TRUE (which it is by default) a plot of the mother wavelet or scaling function is plotted on the active graphics device.

Author(s)

G P Nason

See Also

filter.select, imwdc.object, draw.default.

Examples

#
# Let's use the lennon test image
#
data(lennon)
## Not run: image(lennon)
#
# Now let's do the 2D discrete wavelet transform using Daubechies'
# least-asymmetric wavelet N=6
#
lwd <- imwd(lennon, filter.number=6)
#
# Now let's threshold the 2D DWT
# The resultant class of object is imwdc object.
#
lwdT <- threshold(lwd)
#
# And now draw the wavelet that did this transform
#
## Not run: draw(lwdT)
#
# A nice little two-dimensional wavelet!
#