calcWOI (version 1.0.3)

wavtra: Performs the wavelet transform

Description

This function uses parts the wavelet transform of Eckely et al. (2010). We use the DaubExPhase4 wavelet for all calculations. The inverse A matrix is loaded from constants.rda. The resulting value of each transform is written to the centre of mass of the spectrum, which is also saved in constants.rda due to computation time.

Usage

wavtra(x)

Arguments

x

2D array of dimension 2^n x 2^n with n = 4, 5, ... or 12. Periodic boundaries are assumed.

Value

Returns a 3D array with 2^n x 2^n x 3*n wavelet coefficients. The third dimension includes the wavelet coefficients of North-South scales 1-n, East-West scales 1-n and Diagonal scales 1-n.

References

Eckley, I.A., Nason, G.P. and Treloar, R.L. (2010) Locally stationary wavelet fields with application to the modelling and analysis of image texture. Journal of the Royal Statistical Society (Series C), 59, 595-616.

Eckley, I.A. and Nason, G.P. (2011). LS2W: Implementing the Locally Stationary 2D Wavelet Process Approach in R, Journal of Statistical Software, 43(3), 1-23.

Examples

# NOT RUN {
x <- array(1:(2^12), dim = c(2^6, 2^6))
print(dim(x))
# }