tcctomat               package:rmutil               R Documentation

_C_r_e_a_t_e _o_r _a_d_d _t_o _a _t_i_m_e-_c_o_n_s_t_a_n_t _c_o_v_a_r_i_a_t_e (_t_c_c_o_v) _o_b_j_e_c_t

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

     `tcctomat' creates an object of class, tccov, from a vector or
     matrix containing time-constant baseline covariates or a model
     formula, or combines two such objects.

     Such objects can be printed. Methods are available for extracting
     the covariates, their names, and the formula: `covariates',
     `names', and `formula'. The method, `link{transform}', can
     transform variables in place or by adding new variables to the
     object.

     To obtain the indexing to expand time-constant covariates to the
     size of a repeated measurements response, use `covind'.

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

     tcctomat(ccov, names=NULL, oldccov=NULL, dataframe=TRUE)

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

    ccov: A vector or matrix containing time-constant baseline
          covariates with one row per individual, a model formula using
          vectors of the same size, or an object of class, tccov.

   names: The names of the covariates (if the matrix does not have
          column names).

 oldccov: An object of class, tccov, to which ccov is to be added.

dataframe: If TRUE and factor variables are present, the covariates are
          stored as a dataframe; if FALSE, they are expanded to
          indicator variables. If no factor variables are present,
          covariates are always stored as a matrix.

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

     Returns an object of class, tccov, containing one matrix for the
     covariates (z$ccov) with one row per individual and possibly the
     model formula (z$linear).

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

     J.K. Lindsey

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

     `read.list', `restovec', `rmna', `transform', `tvctomat'.

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

     x1 <- gl(4,1)
     print(tcc1 <- tcctomat(~x1))
     covariates(tcc1)
     covariates(tcc1, name="x12")
     tcctomat(x1)
     tcctomat(x1, dataframe=T)
     x2 <- c(0,0,1,1)
     print(tcc2 <- tcctomat(~x2))
     covariates(tcc2)
     print(tcc3 <- tcctomat(~x1+x2))
     covariates(tcc3)
     covariates(tcc3, names=c("x12","x2"))
     formula(tcc3)
     names(tcc3)
     print(tcc4 <- tcctomat(data.frame(x1,x2)))
     covariates(tcc4)
     print(tcc5 <- tcctomat(data.frame(x1,x2), dataframe=T))
     covariates(tcc5)

