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)
}