moisture            package:DierckxSpline            R Documentation

_V_o_l_u_m_e_t_r_i_c _m_o_i_s_t_u_r_e _c_o_n_t_e_n_t

_D_e_s_c_r_i_p_t_i_o_n:

     16 measurements of volumetric moisture content

_U_s_a_g_e:

     data(moisture)

_F_o_r_m_a_t:

     a data.frame with the following columns:


   _x property

   _y measurement

   _v constant 1

   _w Weight:  constant 1 except for the first 2 and the last
        observations, being 10, 3, 10, respectively.


_D_e_t_a_i_l_s:

     Dierckx (1993, Table 7.2, pp. 129-131)

_S_o_u_r_c_e:

     Dierckx, Paul (1993), _Curve and Surface Fitting with Splines_,
     Springer.

_E_x_a_m_p_l_e_s:

     data(moisture)
     moisture # Dierckx, Table 7.2, p. 130
     f1 <- with(moisture,
       concon(x, y, w, v, s = 0.2))
     f2 <- update(f1, s = 0.04)
     f3 <- update(f1, s = 0.0002)

     g1 <- with(moisture,
       curfit(x, y, w, method = "ls",
              knots = knots(f1)))
     g2 <- update(g1, knots = f2)
     g3 <- update(g1, knots = f3)

