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dof
Compute number of non-zero coefficients in wd object
DESCRIPTION
Compute number of non-zero coefficients in wd object
USAGE
dof(wd)
REQUIRED ARGUMENTS
- wd
- A wavelet decomposition object (such as that
returned by the wd function).
OPTIONAL ARGUMENTS
None.
VALUE
An integer that represents the number of non-zero coefficients
in the input wd object.
SIDE EFFECTS
None.
DETAILS
Very simple function that counts the number of non-zero coefficients
in a wd class object.
RELEASE
Version 3.0 Copyright Guy Nason 1994
SEE ALSO
wd,
wd object,
threshold,
threshold.wd.
EXAMPLES
#
# Let's generate some purely random numbers!!
#
myrandom <- rnorm(512)
#
# Take the discrete wavelet transform
#
myrandomWD <- wd(myrandom)
#
# How many coefficients are non-zero?
#
dof(myrandomWD)
# [1] 512
#
# All of them were nonzero!
#
# Threshold it
#
myrandomWDT <- threshold(myrandomWD, policy="universal")
#
# Now lets see how many are nonzero
#
dof(myrandomWDT)
# [1] 8
#
# Wow so 504 of the coefficients were set to zero! Spooky!
#