WaveThresh Help - draw.default
Draw a picture of a wavelet
DESCRIPTION
Draws pictures of wavelets associated with the wavethresh package.
USAGE
draw.default(filter.number=2, family="DaubExPhase",
resolution=1024, verbose=F, plot.it=T, main="Wavelet Picture",
sub=zwd$filter$name, xlab="x", ylab="psi", dimension=1,
twodplot=persp, enhance=T, efactor=0.05, ...)
OPTIONAL ARGUMENTS
- filter.number
- The number of the filter in the wavelet family
specified by filter to draw, the range of numbers depends
on the family.
- family
- The family of wavelets to use, can be "DaubExPhase" or
"DaubLeAsymm".
- resolution
- The number of points used to form the X-axis of
the plot. Very high resolution pictures can be obtained if
you increase this number.
- verbose
- The function will be chatty if you set this argument
equal to T
- plot.it
- If this is T the function will be plotted on the
current graphics device If it is F then an list containing
two components "x" and "y" will be returned. The (x,y)
pair contain the coordinates of points that would have
been drawn if plot.it were T.
- main
- The main title of the plot
- sub
- The subtitle of the plot
- xlab
- The label for the x axis
- ylab
- The label for the y axis
- dimension
- This argument must be only 1 or 2. If it is 1 then
a 1-d plot will be drawn. If it is 2 then a two-
dimensional plot will be drawn using the function
referenced by the "twodplot" argument.
- enhance
- The effective support of the wavelet is often less
than the actual support. If the enhance argument is set
to T then the wavelet will only be drawn where an
appreciable amount of it exists.
- efactor
- The smallest interval containing the set where the
absolute value of the wavelet exceeds efactor multiplied
by the maximum value of the wavelet. See
Nason
and Silverman (1994) for details.
- ...
Other arguments that could be passed to the plot routines.
REFERENCES
Daubechies, I. (1988) Orthonormal bases of compactly
supported wavelets. Communications on Pure and Applied
Mathematics, 41, 909--996
Nason, G. P. and Silverman, B. W. (1994).
The
discrete wavelet transform in S. Journal of Computational and
Graphical Statistics, 3, 163--191.
SEE ALSO
`draw'
#
# Draw a 1-dimensional Daubechies extremal phase wavelet
#
> draw.default(filter.number=2)
#
# Draw a 2-dimensional Daubechies least asymmetric wavelet
#
> draw.default(filter.number=6, family="DaubLeAsymm", dim=2,
res=256, efactor=0.03)
Wavelets Home Page
G.P.Nason@bristol.ac.uk