BSPDERIV:  B-Spline derivative


 Calling Sequence:

          [dc,dk] = bspderiv(d,c,k)

  INPUT:
 
    d - degree of the B-Spline
    c - control points   double matrix(mc,nc)
    k - knot sequence    double vector(nk)
 
  OUTPUT:
 
    dc - control points of the derivative     double  matrix(mc,nc)
    dk - knot sequence of the derivative      double  vector(nk)
 
  Modified version of Algorithm A3.3 from 'The NURBS BOOK' pg98.

Package: nurbs