opttodes              package:crossdes              R Documentation

_G_e_n_e_r_a_t_i_o_n _o_f _B_a_l_a_n_c_e_d _I_n_c_o_m_p_l_e_t_e _B_l_o_c_k _D_e_s_i_g_n_s _U_s_i_n_g _t_h_e _P_a_c_k_a_g_e _D_o_p_t

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

     The function 'Dopt' of the library 'Dopt' is used to construct
     balanced incomplete block designs (BIBDs). The design is assigned
     to a matrix where rows represent blocks (subjects) and  columns
     represent periods.

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

     opttodes(trt, b, k, iter = 50)

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

     trt: An integer > 1 giving the number of treatments of the design. 

       b: An integer > 1 giving the number of rows (subjects) of the
          design. 

       k: An integer > 1 giving the number of columns (periods) of the
          design. 

    iter: The number of iterations of the function 'Dopt' 

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

     The function 'Dopt' tries to find a D-optimal block design for the
     specified parameters. The resulting design need not be a BIBD. 
     The necessary conditions for the existence are that bk/trt and 
     bk(k-1)/(trt(trt-1)) positive intergers. They are NOT checked
     automatically. Even if they are fulfilled, there need not be a
     BIBD.   If no BIBD is found, the function is iterated. If no BIBD
     is found after 'iter' iterations, the search is terminated. In any
     case, the resulting design is checked by the function 'isGYD', the
     result is displayed on the screen and the resulting design matrix
     is returned.

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

     A matrix that represents the experimental design.

_W_a_r_n_i_n_g:

     This function requires the package 'Dopt'.  As of May 13 2004,
     CRAN states that 'Dopt' is a package in development and that such
     packages may be unstable.

_N_o_t_e:

     As indicated above, the returned design is not necessarily a BIBD
     design.

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

     Oliver Sailer sailer@statistik.uni-dortmund.de

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

     'get.plan', 'Dopt'

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

     opttodes(10,30,4)       # BIBD
     opttodes(3,3,2)         # BIBD, even GYD
     opttodes(5,5,3, 100)    # There is no BIBD for these parameters   

