threshold2d: Setting wavelet coefficients to zero that correspond to...

In jantonelli111/Irregular2dWavelets: Two-dimensional wavelet decompositions of irregular grids

Description

Takes in a vector of coefficients and returns the same vector, but with entries forced to zero that correspond to the desired wavelet levels

Usage

threshold2d(beta, numLevels, remove.x, remove.y)

Arguments

beta	Vector of wavelet coefficients
numLevels	Number of wavelet levels. Should be an integer between 2 and 10
remove.x	Vector of wavelet levels in the X direction that you want removed. Should contain numbers between 1 and numLevels
remove.y	Vector of wavelet levels in the Y direction that you want removed. Should contain numbers between 1 and numLevels

Value

A vector of wavelet coefficients with those corresponding to basis functions involving levels in remove.x or remove.y set to zero

Examples

data(BostonPMsim)
numLevels <- 3
Decomp <- Irregular2dWavelet(x=BostonPMsim$long, 
                             y=BostonPMsim$lat,
                             f=BostonPMsim$pm,
                             numLevels=numLevels)

threshold.betalow4 <- threshold2d(Decomp$beta, numLevels, remove.x=4:numLevels, remove.y=4:numLevels)
threshold.fHatlow4 <- Decomp$Zxy%*%threshold.betalow4

threshold.col = colors(100)[as.numeric(cut(threshold.fHatlow4,breaks = 100))]
map("state","massachusetts", xlim=range(BostonPMsim$long), ylim=range(BostonPMsim$lat))
points(BostonPMsim$long, BostonPMsim$lat, col=threshold.col, cex=.2)

jantonelli111/Irregular2dWavelets documentation built on May 18, 2019, 2:39 p.m.