\name{norder}
\alias{norder}
\alias{norder.fd}
\alias{norder.basisfd}
\alias{norder.default}
\alias{norder.bspline}
\title{
  Order of a B-spline
}
\description{
  norder = number of basis functions minus the number of interior
  knots.  
}
\usage{
norder(x, ...) 
\method{norder}{fd}(x, ...)
\method{norder}{basisfd}(x, ...)
\method{norder}{default}(x, ...)
norder.bspline(x, ...) 
}
\arguments{
  \item{x}{
    Either a basisfd object or an object containing a basisfd object as
    a component.  
  }
  \item{\dots}{optional arguments currently unused} 
}
\details{
  norder throws an error of basisfd[['type']] != 'bspline'.  
}
\value{
  An integer giving the order of the B-spline.  
}
%\references{}
\author{
  Spencer Graves
} 
\seealso{
  \code{\link{create.bspline.basis}}
}
\examples{
bspl1.1 <- create.bspline.basis(norder=1, breaks=0:1)

stopifnot(norder(bspl1.1)==1)

stopifnot(norder(fd(0, basisobj=bspl1.1))==1)

stopifnot(norder(fd(rep(0,4)))==4)

stopifnot(norder(list(fd(rep(0,4))))==4)
\dontrun{
norder(list(list(fd(rep(0,4)))))
Error in norder.default(list(list(fd(rep(0, 4))))) : 
  input is not a 'basisfd' object and does not have a 'basisfd'
component. 
}

stopifnot(norder(create.bspline.basis(norder=1, breaks=c(0,.5, 1))) == 1) 

stopifnot(norder(create.bspline.basis(norder=2, breaks=c(0,.5, 1))) == 2)

# Defaut B-spline basis:  Cubic spline:  degree 3, order 4,
# 21 breaks, 19 interior knots.  
stopifnot(norder(create.bspline.basis()) == 4)

\dontrun{
norder(create.fourier.basis(c(0,12) ))
Error in norder.bspline(x) : 
  object x is of type = fourier;  'norder' is only defined for type = 'bsline'
}

}
\keyword{smooth}