Ldei                   package:LIM                   R Documentation

_S_o_l_v_e_s _a _l_i_n_e_a_r _i_n_v_e_r_s_e _m_o_d_e_l _u_s_i_n_g _l_e_a_s_t _d_i_s_t_a_n_c_e _p_r_o_g_r_a_m_m_i_n_g

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

     Solves a linear inverse model using least distance programming,
     i.e. minimizes the sum of squared unknowns.

     Input presented either:


        *  as matrices E, F, A, B, G, H (Ldei.double)

        *  as a list (Ldei.lim) or

        *  as a lim input file (Ldei.limfile)

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

     Ldei(...)
     Ldei.lim(lim,...)
     Ldei.limfile(file, verbose=TRUE, ...)
     Ldei.character(...)
     Ldei.double(...)

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

    lim : a list that contains the linear inverse model specification,
          as  generated by function 'setup.limfile'. 

   file : name of the inverse input file. 

verbose : if 'TRUE': prints warnings and messages to the screen. 

    ... : other arguments passed to function 'ldei' from
          package'limSolve'. 

_D_e_t_a_i_l_s:

     Solves the following inverse problem:

                       min(sum {Cost_i*x_i}^2)

     subject to

                                 Ax=B


                                Gx>=H

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

     a list containing: 

      X : vector containing the solution of the least distance problem. 

unconstrained.Solution : vector containing the unconstrained solution
          of the least distance problem. 

residualNorm : scalar, the sum of residuals of equalities and violated
          inequalities. 

solutionNorm : scalar, the value of the quadratic function at the
          solution. 

IsError : logical, 'TRUE', if an error occurred. 

  Error : ldei error text. 

   type : ldei. 

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

     Karline Soetaert <k.soetaert@nioo.knaw.nl>

_R_e_f_e_r_e_n_c_e_s:

     Lawson C.L.and Hanson R.J. 1974. SOLVING LEAST SQUARES PROBLEMS,
     Prentice-Hall

     Lawson C.L.and Hanson R.J. 1995. Solving Least Squares Problems.
     SIAM classics in applied mathematics, Philadelphia.       
     (reprint of book)

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

     'ldei', the more general function from package limSolve.

     'Linp', to solve the linear inverse problem by linear programming.

     'Lsei', to solve the linear inverse problem by lsei (least squares
     with equality and inequality constraints).

     function 'ldei' from package'limSolve'.

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

     Ldei(LIMRigaAutumn)

