dpoMatrix-class            package:Matrix            R Documentation

_P_o_s_i_t_i_v_e _s_e_m_i-_d_e_f_i_n_i_t_e, _d_e_n_s_e, _n_u_m_e_r_i_c _m_a_t_r_i_c_e_s

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

     The '"dpoMatrix"' class is the class of positive-semidefinite
     symmetric matrices in nonpacked storage.  The '"dppMatrix"' class
     is the same except in packed storage. Only the upper triangle or
     the lower triangle is required to be available.

_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("dpoMatrix",
     ...)' or from 'crossprod' applied to an '"dgeMatrix"' object.

_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.

     '_x': Object of class '"numeric"'. The numeric values that
          constitute the matrix, stored in column-major order.

     '_D_i_m': Object of class '"integer"'. The dimensions of the matrix
          which must be a two-element vector of non-negative integers.

     '_r_c_o_n_d': Object of class '"numeric"'. A named numeric vector of
          reciprocal condition numbers in either the 1-norm '"O"' or
          the infinity norm '"I"'.

     '_f_a_c_t_o_r_s': Object of class '"list"'.  A named list of
          factorizations that have been computed for the matrix.

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

     Class '"dsyMatrix"', directly. Class '"dgeMatrix"', by class
     '"dsyMatrix"'. Class '"Matrix"', by class '"dsyMatrix"'.

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

     _c_h_o_l 'signature(x = "dpoMatrix")': Returns (and stores) the
          Cholesky decomposition of the matrix 'x'.

     _r_c_o_n_d 'signature(x = "dpoMatrix", type = "character")': Returns
          (and stores) the reciprocal of the condition number of 'x'. 
          The 'type' can be '"O"' for the one-norm (the default) or
          '"I"' for the infinity-norm.  For symmetric matrices the
          result does not depend on the type.

     _s_o_l_v_e 'signature(a = "dpoMatrix", b = "missing")': Return the
          inverse of 'a'.

     _s_o_l_v_e 'signature(a = "dpoMatrix", b = "numeric")': Solve the
          linear system defined by 'a' and 'b', where 'b' can be a
          numeric vector, or a matrix, or a dgeMatrix object.  The
          Cholesky decomposition of 'a' is calculated (if needed) while
          solving the system.

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

     'dsyMatrix-class', 'dgeMatrix-class', 'Matrix', 'rcond', 'chol',
     'solve', 'crossprod'

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

     h6 <- Hilbert(6)
     rcond(h6)
     str(h6)
     solve(h6)
     str(hp6 <- as(h6, "dppMatrix"))

