triangularMatrix-class        package:Matrix        R Documentation

_V_i_r_t_u_a_l _C_l_a_s_s _o_f _T_r_i_a_n_g_u_l_a_r _M_a_t_r_i_c_e_s _i_n _p_a_c_k_a_g_e:_M_a_t_r_i_x

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

     The virtual class of triangular matrices,'"triangularMatrix"',
     from the package 'Matrix' contains numeric and logical, dense and
     sparse matrices, e.g., see the examples.

     The main use will be in methods (and C functions) that can deal
     with all triangular matrices.

_S_l_o_t_s:

     '_u_p_l_o': Object of class '"character"'.  Must be either "U", for
          upper triangular, and "L", for lower triangular.

     '_d_i_a_g': Object of class '"character"'.  Must be either '"U"', for
          unit triangular (diagonal is all ones), or '"N"' for
          non-unit.  The diagonal elements are not accessed internally
          when 'diag' is '"U"' (but need to be allocated, i.e.,
          'length(x)' does not depend on 'diag').

     '_D_i_m, _D_i_m_n_a_m_e_s': The dimension (a length-2 '"integer"') and
          corresponding names (or 'NULL'), inherited from the 'Matrix',
          see there.

_E_x_t_e_n_d_s:

     Class '"Matrix"', directly.

_M_e_t_h_o_d_s:

     There's a C function 'triangularMatrix_validity()' called by the
     internal validity checking functions.

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

     Classes 'symmetricMatrix', and, e.g., 'dtrMatrix' for numeric
     _dense_ matrices, or 'ltCMatrix' for a logical _sparse_ matrix
     subclass of '"triangularMatrix"'.

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

     showClass("triangularMatrix")

     ## The names of direct subclasses:
     scl <- getClass("triangularMatrix")@subclasses
     directly <- sapply(lapply(scl, slot, "by"), length) == 0
     names(scl)[directly]

