factorize            package:conf.design            R Documentation

_G_e_n_e_r_i_c _f_u_n_c_t_i_o_n.

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

     The default method factorizes positive numeric integer arguments,
     returning a vector of prime factors.  The factor method can be
     used to generate pseudo-factors.  It accepts a factor, f, as
     principal argument and returns a design with factors fa, fb, ...{}
     each with a prime number of levels such that f is model equivalent
     to join(fa, fb, ...{}).

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

     factorize(x, ...)

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

       x: Principal argument.  At this stage, it may be a numeric
          vector to elicit the default method, or a factor to elicit
          the factor method.

     ...: Additional arguments, if any.

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

     Factorizes by a clumsy though effective enough way for small
     integers. May become very slow if some prime factors are large. 
     For the factor method it generates pseudo factors in the usual
     way.

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

     A vector of (numeric) factors for numeric arguments, or a design
     with (S-PLUS) factors with prime numbers of levels for factor
     arguments.

_S_i_d_e _E_f_f_e_c_t_s:

     None.

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

     conf.design, join

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

      factorize(18)
      # [1] 2 3 3
      f <- factor(rep(0,5), rep(6,5))
      fd <- factorize(f)

