dyadic.check.R

# fields  is a package for analysis of spatial data written for
# the R software environment .
# Copyright (C) 2018
# University Corporation for Atmospheric Research (UCAR)
# Contact: Douglas Nychka, nychka@ucar.edu,
# National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307-3000
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with the R software environment if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
# or see http://www.r-project.org/Licenses/GPL-2    
dyadic.check <- function(n, cut.p = 2) {
    # checks that n is of the form
    # n=p*2^m where p <= cut.p
    n2 <- as.integer(n)
    while (n2 > cut.p) {
        if (n2%%2 != 0) {
            cat(n, "must equal p*2^m where p is less than or equal to ", 
                cut.p, fill = TRUE)
            return(FALSE)
        }
        n2 <- n2/2
    }
    return(TRUE)
}