function [Bp, Bpp] = makeB(baseMVA, bus, branch, alg)%MAKEB   Builds the FDPF matrices, B prime and B double prime.%   [Bp, Bpp] = makeB(baseMVA, bus, branch, alg) returns the two%   matrices B prime and B double prime used in the fast decoupled power%   flow. Does appropriate conversions to p.u.%   MATPOWER%   $Id: makeB.m,v 1.5 2005/07/08 18:58:19 ray Exp $%   by Ray Zimmerman, PSERC Cornell%   Copyright (c) 1996-2004 by Power System Engineering Research Center (PSERC)%   See http://www.pserc.cornell.edu/matpower/ for more info.%% constantsnb = size(bus, 1);          %% number of busesnl = size(branch, 1);       %% number of lines%% define named indices into bus, branch matrices[PQ, PV, REF, NONE, BUS_I, BUS_TYPE, PD, QD, GS, BS, BUS_AREA, VM, ...    VA, BASE_KV, ZONE, VMAX, VMIN, LAM_P, LAM_Q, MU_VMAX, MU_VMIN] = idx_bus;[F_BUS, T_BUS, BR_R, BR_X, BR_B, RATE_A, RATE_B, RATE_C, ...    TAP, SHIFT, BR_STATUS, PF, QF, PT, QT, MU_SF, MU_ST, ...    ANGMIN, ANGMAX, MU_ANGMIN, MU_ANGMAX] = idx_brch;%%-----  form Bp (B prime)  -----temp_branch = branch;                       %% modify a copy of branchtemp_bus = bus;                             %% modify a copy of bustemp_bus(:, BS) = zeros(nb, 1);             %% zero out shunts at busestemp_branch(:, BR_B) = zeros(nl, 1);        %% zero out line charging shuntstemp_branch(:, TAP) = ones(nl, 1);          %% cancel out tapsif alg == 2                                 %% if XB method    temp_branch(:, BR_R) = zeros(nl, 1);        %% zero out line resistanceendBp = -imag( makeYbus(baseMVA, temp_bus, temp_branch) );%%-----  form Bpp (B double prime)  -----if nargout == 2    temp_branch = branch;                       %% modify a copy of branch    temp_branch(:, SHIFT) = zeros(nl, 1);       %% zero out phase shifters    if alg == 3                                 %% if BX method        temp_branch(:, BR_R) = zeros(nl, 1);        %% zero out line resistance    end    Bpp = -imag( makeYbus(baseMVA, bus, temp_branch) );endreturn;