dsCMatrix-class            package:Matrix            R Documentation

_S_y_m_m_e_t_r_i_c, _c_o_m_p_r_e_s_s_e_d, _s_p_a_r_s_e _c_o_l_u_m_n _m_a_t_r_i_c_e_s

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

     The 'dsCMatrix' class is a class of symmetric, sparse matrices in
     the compressed, column-oriented format.  In this implementation
     the non-zero elements in the columns are sorted into increasing
     row order. The 'dsTMatrix' class is a class of symmetric, sparse
     matrices in triplet format.

_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("dsCMatrix",
     ...)' or 'new("dsTMatrix", ...)'

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

     '_u_p_l_o': A character object indicating if the upper triangle ('"U"'
          or '"u"') or the lower triangle ('"L"' or '"l"') is stored. 
          At present only the lower triangle form is allowed.

     '_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 the 'dsCMatrix' class.)

     '_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.

     '_j': Object of class '"integer"' of length nnzero (number of
          non-zero elements).  These are the column numbers for each
          non-zero element in the matrix. (Only present in the
          'dsTMatrix' class.) 

     '_x': Object of class '"numeric"' - the non-zero elements of the
          matrix.

     '_f_a_c_t_o_r_s': Object of class '"list"' - a list of factorizations of
          the matrix. 

     '_D_i_m': Object of class '"integer"' - the dimensions of the matrix
          - must be an integer vector with exactly two non-negative
          values.

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

     Class '"dgCMatrix"', directly.

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

     _s_o_l_v_e 'signature(a = "dsCMatrix", b = "matrix")': Solve a linear
          system of equations defined by 'x' using a Cholesky
          decomposition.

     _c_h_o_l 'signature(x = "dsCMatrix", pivot = "logical")': Returns (and
          stores) the Cholesky decomposition of the matrix 'x'. If
          'pivot' is 'TRUE' (the default) Metis is used to create a
          reordering of the rows and columns of 'x' so as to minimize
          fill-in.

     _d_e_t_e_r_m_i_n_a_n_t 'signature(x = "dsCMatrix", logarithm = "missing")':
          Evaluate the determinant of 'x' on the logarithm scale.  This
          creates and stores the Cholesky factorization.

     _d_e_t_e_r_m_i_n_a_n_t 'signature(x = "dsCMatrix", logarithm = "logical")':
          Evaluate the determinant of 'x' on the logarithm scale or
          not, according to the 'logarithm' argument.  This creates and
          stores the Cholesky factorization.

     _t 'signature(x = "dsCMatrix")': Transpose.  Because 'x' is
          symmetric this has no effect.

     _t 'signature(x = "dsTMatrix")': Transpose.  For the 'dsTMatrix'
          class the row and column indices are interchanged so that a
          matrix for which the upper triangle is stored produces a
          matrix for which the lower triangle is stored and vice versa.

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

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

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

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

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

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

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

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

     'dgCMatrix-class', 'dgTMatrix-class', 'dgeMatrix-class'

