WaveThresh
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draw.imwdc
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
draw.imwdc(wd, resolution=128, ...)
REQUIRED ARGUMENTS
- wd
- The imwd class object whose associated wavelet
you wish to draw. (I know its called wd, sorry).
OPTIONAL ARGUMENTS
- 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.
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.
SIDE EFFECTS
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.
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.
RELEASE
Version 2 Copyright Guy Nason 1993
SEE ALSO
filter.select,
imwdc object,
draw.default.
EXAMPLES
#
# Let's use the lennon test image
#
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
#
draw(lwdT)
#
# A nice little two-dimensional wavelet!
#