maxwell                 package:VGAM                 R Documentation

_M_a_x_w_e_l_l _D_i_s_t_r_i_b_u_t_i_o_n _F_a_m_i_l_y _F_u_n_c_t_i_o_n

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

     Estimating the parameter of the Maxwell  distribution by maximum
     likelihood estimation.

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

     maxwell(link = "loge")

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

    link: Parameter link function applied to the parameter a.  See
          'Links' for more choices. A log link is the default because
          the parameter is positive.

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

     The Maxwell distribution, which is used in the area of
     thermodynamics, has a probability density function that can be
     written

         f(y) = sqrt(2/pi) * a^(3/2) * y^2 * exp(-0.5*a*y^2)

     for y>0 and a>0.  The mean of Y is sqrt(8 / (a * pi)) (returned as
     the fitted values), and its variance is (3*pi - 8)/(pi*a).

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

     An object of class '"vglmff"' (see 'vglmff-class'). The object is
     used by modelling functions such as 'vglm', 'rrvglm' and 'vgam'.

_N_o_t_e:

     A related distribution is the Rayleigh distribution.

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

     T. W. Yee

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

     von Seggern, D. H. (1993) _CRC Standard Curves and Surfaces_, Boca
     Raton, FL.: CRC Press.

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

     'Maxwell', 'rayleigh'.

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

     y = rmaxwell(n <- 1000, a=exp(2))
     fit = vglm(y ~ 1, maxwell, trace=TRUE, crit="c")
     coef(fit, matrix=TRUE)
     Coef(fit)

