var2cor                package:nlreg                R Documentation

_C_o_n_v_e_r_t _C_o_v_a_r_i_a_n_c_e _M_a_t_r_i_x _t_o _C_o_r_r_e_l_a_t_i_o_n _M_a_t_r_i_x - _G_e_n_e_r_i_c _F_u_n_c_t_i_o_n

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

     This function converts the covariance matrix from a fitted model
     into the correlation matrix.

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

     var2cor(object, ...)

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

  object: any fitted model object from which a covariance matrix may be
          extracted. 

     ...: absorbs any additional argument. 

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

     This function is generic (see 'methods'); method  functions can be
     written to handle specific classes of data.   Classes which
     already have methods for this function include:  'nlreg',
     'summary.nlreg', 'mpl' and 'summary.mpl'.

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

     the correlation matrix of the estimates from a fitted model.

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

     'var2cor.nlreg', 'var2cor.mpl',  'methods'

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

     data(metsulfuron)
     metsulfuron.nl <- 
         nlreg( log(area) ~ log( b1+(b2-b1) / (1+(dose/b4)^b3) ), 
                weights = ~( 1+dose^exp(g) )^2, data = metsulfuron, 
                start = c(b1 = 138, b2 = 2470, b3 = 2, b4 = 0.07, g = log(0.3)),
                hoa = TRUE )
     var2cor( metsulfuron.nl )
     ##
     metsulfuron.sum <- summary( metsulfuron.nl, corr = FALSE )
     var2cor( metsulfuron.sum )

