Amatdual {adlift}R Documentation

Amatdual

Description

Combines filter matrices to produce a refinement matrix A for a wavelet transform.

Usage

Amatdual(steps, pointsin, removelist, nbrs, weights, alpha)

Arguments

steps

a value indicating which refinement matrix to construct. It refers to the number of points already removed during the transform.

pointsin

The indices of gridpoints still to be removed.

removelist

a vector of indices into envX of the lifted coefficients during the transform (in the order of removal).

nbrs

indices of the neighbours used in the last step of the decomposition.

weights

the prediction weights obtained from the regression in the prediction step of the transform.

alpha

the update weights used to update lengths and coeff.

Details

The function uses the prediction and update weights to construct the filter matrices Hdual and Gdual. Combining these two matrices results in the refinement matrix Adual.

Value

Adual

the refinement matrix for the particular step of the transform.

Hdual

the high-pass filter matrix for the current step of the transform.

Gdual

the low-pass filter matrix for the current step of the transform.

o

the indices of nbrs into the vector of pointsin and the steps removed points of the transform.

alpha

the update weights used to update lengths and coeff.

weights

the prediction weights obtained from the regression in the prediction step of the transform.

Note

This function has been left in the package for completeness. However, the transform matrix is (optionally) computed within the forward lifting transform function fwtnp.

Author(s)

Matt Nunes (nunesrpackages@gmail.com), Marina Knight

See Also

transmatdual, fwtnp

Examples

#
x<-runif(256)
y<-make.signal2("doppler",x=x)
a<-fwtnp(x,y,LocalPred=AdaptNeigh,neighbours=2)
#
Adual<-Amatdual(90,a$pointsin,a$removelist,a$neighbrs[[90]],
a$gamlist[[90]],a$alphalist[[90]])
#
Adual
#
#the 90th refinement matrix for the transform above.
#

[Package adlift version 1.4-5 Index]