lrt                  package:merror                  R Documentation

_L_i_k_e_l_i_h_o_o_d _r_a_t_i_o _t_e_s_t _f_o_r _a_l_l _b_e_t_a_s _e_q_u_a_l_l_i_n_g _o_n_e.

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

     Likelihood ratio test statistic - H0: all betas = one.

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

     lrt(x, M = 40)

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

       x: n (no. of items) x N (no. of methods) matrix or data.frame
          containing the measurements. N must be greater than 3 and n >
          N.

       M: Maximum no. of iterations for convergence. 

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

     See Jaech, pp. 204-205.

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

n.items : No.of items.

N.methods : No. of methods.'

beta.bars : N vector of estimated betas.

 lambda : Chi-square test statistic.

     df : Degrees of freedom for the test (N-1).'

p.value : Empirical significance level for the observed test
          statistic.'

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

     Richard A. Bilonick rab@nauticom.net

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

     Jaech, J. L. (1985) _Statistical Analysis of Measurement Errors_.
     New York: Wiley.

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

     'ncb.od','cb.pd','pm2.5'

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

     data(pm2.5)

     lrt(pm2.5) # compare all 5 samplers (4 personal and 1 frm)

     lrt(pm2.5[,1:4]) # compare only the personal samplers

     stem(lrt(pm2.5)$beta.bars) # examine the estimated betas

