CHMfactor-class            package:Matrix            R Documentation

_C_H_O_L_M_O_D-_b_a_s_e_d _C_h_o_l_e_s_k_y _F_a_c_t_o_r_i_z_a_t_i_o_n_s

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

     The virtual class '"CHMfactor"' is a class of CHOLMOD-based
     Cholesky factorizations of symmetric, sparse, compressed,
     column-oriented matrices.  Such a factorization is simplicial
     (virtual class '"CHMsimpl"') or supernodal (virtual class
     '"CHMsuper"').  Objects that inherit from these classes are either
     numeric factorizations (classes '"dCHMsimpl"' and '"dCHMsuper"')
     or symbolic factorizations (classes '"nCHMsimpl"' and
     '"nCHMsuper"').

_O_b_j_e_c_t_s _f_r_o_m _t_h_e _C_l_a_s_s:

     Objects can be created by calls of the form 'new("dCHMsuper",
     ...)' but are more commonly created via 'Cholesky()'. applied to 
     'dsCMatrix' or 'lsCMatrix' objects.

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

     of '"CHMfactor"' and all classes inheriting from it:

     '_p_e_r_m': An integer vector giving the 0-based permutation of the
          rows and columns chosen to reduce fill-in and for
          post-ordering.

     '_c_o_l_c_o_u_n_t': Object of class '"integer"' .... 

     '_t_y_p_e': Object of class '"integer"' .... 

     Slots of the non virtual classes "[dl]CHM(super|simpl)":

     '_p': Object of class '"integer"' of pointers, one for each column,
          to the initial (zero-based) index of elements in the column.
          Only present in classes that contain '"CHMsimpl"'.

     '_i': Object of class '"integer"' of length nnzero (number of
          non-zero elements).  These are the row numbers for each
          non-zero element in the matrix.  Only present in classes that
          contain '"CHMsimpl"'.

     '_x': For the '"d*"' classes: '"numeric"' - the non-zero elements
          of the matrix.

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

     _c_o_e_r_c_e 'signature(from = "CHMfactor", to = "sparseMatrix")'

     _i_m_a_g_e 'signature(x = "CHMfactor")'

     _s_o_l_v_e 'signature(a = "CHMfactor", b = "ddenseMatrix")' The 'solve'
          methods for a '"CHMfactor"' object take an optional third
          argument 'system' whose value can be one of the character
          strings '"A"', '"LDLt"', '"LD"', '"DLt"', '"L"', '"Lt"',
          '"D"', '"P"' or '"Pt"'.  This argument describes the system
          to be solved.  The default is to solve 'Ax = b' for 'x' where
          'A' is sparse, positive-definite matrix that was factored to
          produce '"a"'.

     _s_o_l_v_e 'signature(a = "CHMfactor", b = "dsparseMatrix")'

     _s_o_l_v_e 'signature(a = "CHMfactor", b = "matrix")'

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

     'Cholesky', also for examples; class 'dgCMatrix'.

