Max                   package:VGAM                   R Documentation

_M_a_x_i_m_a

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

     Generic function for the _maxima_ (maximums) of a model.

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

     Max(object, ...)

_A_r_g_u_m_e_n_t_s:

  object: An object for which the computation or extraction of a
          maximum (or maxima) is meaningful. 

     ...: Other arguments fed into the specific methods function of the
          model. Sometimes they are fed into the methods function for
          'Coef'. 

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

     Different models can define a maximum in different ways. Many
     models have no such notion or definition.

     Maxima occur in quadratic and additive ordination, e.g., CQO or
     UQO or CAO. For these models the maximum is the fitted value at
     the optimum. For quadratic ordination models there is a formula
     for the optimum but for additive ordination models the optimum
     must be searched for numerically. If it occurs on the boundary,
     then the optimum is undefined. For a valid optimum, the fitted
     value at the optimum is the maximum.

_V_a_l_u_e:

     The value returned depends specifically on the methods function
     invoked.

_A_u_t_h_o_r(_s):

     Thomas W. Yee

_R_e_f_e_r_e_n_c_e_s:

     Yee, T. W. (2004) A new technique for maximum-likelihood canonical
     Gaussian ordination. _Ecological Monographs_, *74*, 685-701.

     Yee, T. W. (2006) Constrained additive ordination. _Ecology_,
     *87*, 203-213.

_S_e_e _A_l_s_o:

     'Max.qrrvglm', 'Tol', 'Opt'.

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

     ## Not run: 
     data(hspider)
     set.seed(111)  # This leads to the global solution
     hspider[,1:6] = scale(hspider[,1:6]) # Standardized environmental vars
     p1 = cqo(cbind(Alopacce, Alopcune, Alopfabr, Arctlute, Arctperi,
                    Auloalbi, Pardlugu, Pardmont, Pardnigr, Pardpull,
                    Trocterr, Zoraspin) ~
              WaterCon + BareSand + FallTwig + CoveMoss + CoveHerb + ReflLux,
              Bestof = 2,
              fam = quasipoissonff, data = hspider, Crow1positive=FALSE)

     Max(p1)

     index = 1:ncol(p1@y)
     persp(p1, col=index, las=1, lwd=2)
     abline(h=Max(p1), lty=2, col=index)

     ## End(Not run)

