\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, ...)

#NOTE:  The following is required by CRAN rules that
# function names like "as.numeric" must follow the documentation
# standards for S3 generics, even when they are not.
# Please ignore the following line:
\method{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}