a1Table              package:adaptTest              R Documentation

_F_u_n_c_t_i_o_n _t_o _p_r_o_d_u_c_e _t_a_b_l_e_s _o_f _a_l_p_h_a_1

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

     This function produces tables of alpha1 for a grid of different
     choices of alpha and alpha0.

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

     a1Table(typ, a = NA, a0 = NA, Pocock = FALSE, round = FALSE)

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

     typ: type of test: '"b"' for Bauer and Koehne (1994), '"l"' for
          Lehmacher and Wassmer (1999), '"v"' for Vandemeulebroecke
          (2006) and '"h"' for the horizontal conditional error
          function

       a: _vector_ of different choices of alpha, the overall test
          level

      a0: _vector_ of different choices of alpha0, the futility
          stopping bound

  Pocock: logical determining whether the "Pocock-type" should be
          calculated or the full level should be applied after the
          second stage (see details; default: full level after second
          stage).

   round: rounding specification, logical or integer (see details;
          default: no rounding)

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

     This function produces tables of alpha1 on a grid spanned by the
     _vectors_ 'a' and 'a0' (i.e., alpha and alpha0). This is done
     either for the "Pocock-type" (i.e., under the condition alpha1 =
     alpha2: 'Pocock = TRUE') or using the full level after the second
     stage (alpha = alpha2: 'Pocock = FALSE' (the default)). The
     function 'a1Table' can be a convenient shortcut for a repeated use
     of 'tsT'; see this latter function for further details.

     The result is rounded to 'round' digits after the comma ('round =
     TRUE' rounds to 1 digit; 'round = FALSE' and 'round = 0' prevent
     rounding).

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

     'a1Table' returns a matrix of alpha1 values, with the
     corresponding alpha and alpha0 values being displayed as dimnames.

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

     Marc Vandemeulebroecke

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

     Bauer, P., Koehne, K. (1994). Evaluation of experiments with
     adaptive interim analyses. _Biometrics_ 50, 1029-1041.

     Lehmacher, W., Wassmer, G. (1999). Adaptive sample size
     calculations in group sequential trials. _Biometrics_ 55,
     1286-1290.

     Vandemeulebroecke, M. (2006). An investigation of two-stage tests.
     _Statistica Sinica_ 16, 933-951.

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

     'adaptTest' package description, 'tsT'

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

     ## Produce basic reference tables for the test by Vandemeulebroecke (2006)
     alpha  <- c(0.1, 0.05, 0.025, 0.01)
     alpha0 <- 1:10/10
     a1Table(typ="v", a=alpha, a0=alpha0, Pocock=FALSE)
     a1Table(typ="v", a=alpha, a0=alpha0, Pocock=TRUE)

