Calculates the Cross-covariance between multiple wavelet transfomations (dwt or modwt)
wccv(x, decomp = "modwt", filter = "haar", nlevels = NULL)Returns a matrix of lists of all the possible pair cross-covariance, variance of each wavelet cross-covariance and its 95
If nlevels is not specified, it is set to \(\left\lfloor {{{\log }_2}\left( {length\left( x \right)} \right)} \right\rfloor\)