I take the liberty of pasting the on-line documentation for package "wavelets", functions "dwt" and  "wt.filter",  pertinent to the wavelet/filter choice. 
While I apologize for my verbose messages with huge attachments, I encourage whoever loads packages to CRAN to take some minutes to reread the attached documentation.

Usage
dwt(X, filter="la8", n.levels, boundary="periodic", fast=TRUE)

filter Either a wt.filter object, a character string indicating which wavelet filter to use in the decomposition, or a numeric vector of wavelet coefficients (not scaling coefficients). See help(wt.filter) for acceptable filter names 

wt.filter(filter="la8", modwt=FALSE)

Arguments
filter A character string indicating which wavelet transform filter to compute ....

Details
The character strings currently supported are derived from one of four classes of wavelet transform filters: Daubechies, Least Asymetric, Best Localized and Coiflet. The prefixes for filters of these classes are d, la, bl and c, respectively. Following the prefix, the filter name consists of an integer indicating length. Supported lengths are as follows: 

Daubechies
2,4,6,8,10,12,14,16,18,20. 
Least Asymetric
8,10,12,14,16,18,20. 

Now let's try to pick filter "d2" ....

> X1 <- c(.2,-.4,-.6,-.5,-.8,-.4,-.9,0,-.2,.1,-.1,.1,.7,.9,0,.3)
> X2 <- c(.2,-.4,-.6,-.5,-.8,-.4,-.9,0,-.2,.1,-.1,.1,-.7,.9,0,.3)
> 
> # combine them and compute DWT
> newX <- cbind(X1,X2)
> wt <- dwt(newX,filter="d2", n.levels=3, boundary="reflection", fast=FALSE)
Error in wt.filter(filter) : Invalid filter name.

> wt.filter("d2")
Error in wt.filter("d2") : Invalid filter name.

Regards,
Maura





tutti i telefonini TIM!


	[[alternative HTML version deleted]]


