dof {wavethresh}

Compute number of non-zero coefficients in wd object

Description

Compute number of non-zero coefficients in wd object

Usage

dof(wd)

Arguments

wd

A wavelet decomposition object (such as that returned by the wd function).

Details

Very simple function that counts the number of non-zero coefficients in a wd class object.

Value

An integer that represents the number of non-zero coefficients in the input wd object.

RELEASE

Version 3.0 Copyright Guy Nason 1994

Author(s)

G P Nason

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!
#