polySpline              package:splines              R Documentation

_P_i_e_c_e_w_i_s_e _P_o_l_y_n_o_m_i_a_l _S_p_l_i_n_e _R_e_p_r_e_s_e_n_t_a_t_i_o_n

_D_e_s_c_r_i_p_t_i_o_n:

     Create the piecewise polynomial representation of a spline object.

_U_s_a_g_e:

     polySpline(object, ...)
     as.polySpline(object, ...)

_A_r_g_u_m_e_n_t_s:

  object: An object that inherits from class 'spline'.

     ...: Optional additional arguments.  At present no additional
          arguments are used.

_V_a_l_u_e:

     An object that inherits from class 'polySpline'.  This is the
     piecewise polynomial representation of a univariate spline
     function. It is defined by a set of distinct numeric values called
     knots.  The spline function is a polynomial function between each
     successive pair of knots.  At each interior knot the polynomial
     segments on each side are constrained to have the same value of
     the function and some of its derivatives.

_A_u_t_h_o_r(_s):

     Douglas Bates and Bill Venables

_S_e_e _A_l_s_o:

     'interpSpline', 'periodicSpline', 'splineKnots', 'splineOrder'

_E_x_a_m_p_l_e_s:

     require(graphics)
     ispl <- polySpline( interpSpline( weight ~ height,  women, bSpline = TRUE ) )
     print( ispl )   # print the piecewise polynomial representation
     plot( ispl )    # plots over the range of the knots
     points( women$height, women$weight )