function totalcost = totcost(gencost, Pg)%TOTCOST    Computes total cost for generators at given output level.%   totalcost = totcost(gencost, Pg) computes total cost for generators given%   a matrix in gencost format and a column vector or matrix of generation%   levels. The return value has the same dimensions as Pg. Each row%   of gencost is used to evaluate the cost at the points specified in the%   corresponding row of Pg.%   MATPOWER%   $Id: totcost.m,v 1.5 2004/08/23 20:59:54 ray Exp $%   by Ray Zimmerman, PSERC Cornell%   & Carlos E. Murillo-Sanchez, PSERC Cornell & Universidad Autonoma de Manizales%   Copyright (c) 1996-2004 by Power System Engineering Research Center (PSERC)%   See http://www.pserc.cornell.edu/matpower/ for more info.[PW_LINEAR, POLYNOMIAL, MODEL, STARTUP, SHUTDOWN, N, COST] = idx_cost;[ng, m] = size(gencost);totalcost = zeros(ng, size(Pg, 2));if ~isempty(gencost)  ipwl = find(gencost(:, MODEL) == PW_LINEAR);  ipol = find(gencost(:, MODEL) == POLYNOMIAL);  if ~isempty(ipwl)    x = gencost(:, COST:2:(m-1));    y = gencost(:, (COST+1):2:m);    for i = ipwl'      if gencost(i, N) > 0        j1 = 1:(gencost(i, N) - 1);    j2 = 2:gencost(i, N);        pp = mkpp(x(i, 1:gencost(i, N))', [(y(i,j2) - y(i,j1)) ./ (x(i,j2) - x(i,j1));  y(i,j1)]');        totalcost(i,:) = ppval(pp, Pg(i,:));      end    end  end  for i = ipol'    totalcost(i,:)= polyval(gencost(i, COST:(COST+gencost(i, N)-1) ), Pg(i,:) );  endendreturn;