R help - Feb 2011 - tsboot fails on Seasonal Mann-Kendall (seaKen function, wq package)

Dear R-users,

  tsboot fails when I try to perform a block bootstrap on seaKen 
(package wq):

these commands:

require(wq)
require(datasets)
boot.block.sen <- function(data){seaKen(data)[[1]]}
tsboot(sunspot.month, boot.block.sen, R=1999, l=12, sim="fixed")

return:
Error in seaKen(data) : x must be a 'ts'

Any suggestion on how might I change seaKen in order to use it with 
tsboot? Or how might I write my "statistic" in tsboot?

I am using: R version 2.11.1 (2010-05-31) on a Debian testing x86_64

Thanks, regards,

  Alessandro

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alessandro Bigi
Dipartimento di Ingegneria Meccanica e Civile
University of Modena and Reggio Emilia
via Vignolese 905/b, I-41125 Modena
phone: +39-059-2056328
fax:   +39-059-2056126
skype: ale.bigi
email: alessandro.bigi at unimore.it
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