function TorF = have_fcn(tag)%HAVE_FCN  Test for optional functionality.%   TorF = have_fcn(tag) returns 1 if the optional functionality is%   available, 0 otherwise.%%   Possible values for input tag and their meanings:%       bpmpd       - bp(), BPMPD interior point solver%       constr      - constr(), solver from Optimization Toolbox 1.x/2.x%       fmincon     - fmincon(), solver from Optimization Toolbox 2.x +%       linprog     - linprog(), LP solver from Optimization Toolbox 2.x +%       lp          - lp(), LP solver from Optimization Toolbox 1.x/2.x%       minopf      - minopf(), MINOPF, MINOS-based OPF solver%       quadprog    - quadprog(), QP solver from Optimization Toolbox 2.x +%       qp          - qp(), QP solver from Optimization Toolbox 1.x/2.x%       smartmarket - runmkt() and friends, for running an auction%       sparse_lp   - LP solver used by mp_lp can handle sparse matrices%       sparse_qp   - QP solver used by mp_qp can handle sparse matrices%   MATPOWER%   $Id: have_fcn.m,v 1.2 2004/09/01 18:18:21 ray Exp $%   by Ray Zimmerman, PSERC Cornell%   Copyright (c) 2004 by Power System Engineering Research Center (PSERC)%   See http://www.pserc.cornell.edu/matpower/ for more info.switch tag    case 'bpmpd'        TorF = exist(which('bp')) == 3;    case 'constr'        TorF = exist(which('constr')) == 2 & exist('foptions');    case 'fmincon'        TorF = exist(which('fmincon')) == 2;    case 'linprog'        TorF = exist(which('linprog')) == 2;    case 'lp'        TorF = exist(which('lp')) == 2;    case 'minopf'        TorF = exist(which('minopf')) == 3;    case 'quadprog'        TorF = exist(which('quadprog')) == 2;    case 'qp'        TorF = exist(which('qp')) == 2;    case 'smartmarket'        TorF = exist(which('runmkt')) == 2;    case 'sparse_lp'        TorF = have_fcn('bpmpd') | have_fcn('linprog');    case 'sparse_qp'        TorF = have_fcn('bpmpd') | have_fcn('quadprog');    otherwise        error(sprintf('have_fcn: unknown functionality %s', tag));endreturn;