

_G_e_n_e_r_a_t_e _F_a_c_t_o_r _L_e_v_e_l_s

     gl(n, k, length = n*k, labels=1:n, ordered=FALSE)

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

     This function generates `factor's by specifying the
     pattern of their levels.  The result has levels from
     `1' to `n' with each value replicated in groups of
     length `k' out to a total length of `length'.  Labels
     for the resulting factor levels can be optionally
     specified with the arguments `labels' and the factor
     levels can be made ordered by specifying
     `ordered=TRUE'.  `gl' is modelled on the GLIM function
     of the same name.

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

     the underlying `factor(.)'.

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

     # First control, then treatment:
     gl(2,8, label=c("Ctnrl","Treat"))
     # 20 alternating 1s and 2s
     gl(2, 1, 20)
     # alternating pairs of 1s and 2s
     gl(2, 2, 20)

