コード例 #1
0
ファイル: t_qps_pypower.py プロジェクト: Anastien/PYPOWER
def t_qps_pypower(quiet=False):
    """Tests of C{qps_pypower} QP solvers.

    @author: Ray Zimmerman (PSERC Cornell)
    """
    algs = [200, 250, 400, 500, 600, 700]
    names = ['PIPS', 'sc-PIPS', 'IPOPT', 'CPLEX', 'MOSEK', 'Gurobi']
    check = [None, None, 'ipopt', 'cplex', 'mosek', 'gurobipy']

    n = 36
    t_begin(n * len(algs), quiet)

    for k in range(len(algs)):
        if check[k] is not None and not have_fcn(check[k]):
            t_skip(n, '%s not installed' % names[k])
        else:
            opt = {'verbose': 0, 'alg': algs[k]}

            if names[k] == 'PIPS' or names[k] == 'sc-PIPS':
                opt['pips_opt'] = {}
                opt['pips_opt']['comptol'] = 1e-8
            if names[k] == 'CPLEX':
#               alg = 0        ## default uses barrier method with NaN bug in lower lim multipliers
                alg = 2        ## use dual simplex
                ppopt = ppoption(CPLEX_LPMETHOD = alg, CPLEX_QPMETHOD = min([4, alg]))
                opt['cplex_opt'] = cplex_options([], ppopt)

            if names[k] == 'MOSEK':
#                alg = 5        ## use dual simplex
                ppopt = ppoption()
#                ppopt = ppoption(ppopt, MOSEK_LP_ALG = alg)
                ppopt = ppoption(ppopt, MOSEK_GAP_TOL=1e-9)
                opt['mosek_opt'] = mosek_options([], ppopt)

            t = '%s - 3-d LP : ' % names[k]
            ## example from 'doc linprog'
            c = array([-5, -4, -6], float)
            A = sparse([[1, -1,  1],
                        [3,  2,  4],
                        [3,  2,  0]], dtype=float)
            l = None
            u = array([20, 42, 30], float)
            xmin = array([0, 0, 0], float)
            x0 = None
            x, f, s, _, lam = qps_pypower(None, c, A, l, u, xmin, None, None, opt)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, [0, 15, 3], 6, [t, 'x'])
            t_is(f, -78, 6, [t, 'f'])
            t_is(lam['mu_l'], [0, 0, 0], 13, [t, 'lam.mu_l'])
            t_is(lam['mu_u'], [0, 1.5, 0.5], 9, [t, 'lam.mu_u'])
            t_is(lam['lower'], [1, 0, 0], 9, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - unconstrained 3-d quadratic : ' % names[k]
            ## from http://www.akiti.ca/QuadProgEx0Constr.html
            H = sparse([
                [ 5, -2, -1],
                [-2,  4,  3],
                [-1,  3,  5]
            ], dtype=float)
            c = array([2, -35, -47], float)
            x0 = array([0, 0, 0], float)
            x, f, s, _, lam = qps_pypower(H, c, opt=opt)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, [3, 5, 7], 8, [t, 'x'])
            t_is(f, -249, 13, [t, 'f'])
            t_ok(len(lam['mu_l']) == 0, [t, 'lam.mu_l'])
            t_ok(len(lam['mu_u']) == 0, [t, 'lam.mu_u'])
            t_is(lam['lower'], zeros(shape(x)), 13, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - constrained 2-d QP : ' % names[k]
            ## example from 'doc quadprog'
            H = sparse([[ 1, -1],
                        [-1,  2]], dtype=float)
            c = array([-2, -6], float)
            A = sparse([[ 1, 1],
                        [-1, 2],
                        [ 2, 1]], dtype=float)
            l = None
            u = array([2, 2, 3], float)
            xmin = array([0, 0])
            x0 = None
            x, f, s, _, lam = qps_pypower(H, c, A, l, u, xmin, None, x0, opt)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, array([2., 4.]) / 3, 7, [t, 'x'])
            t_is(f, -74. / 9, 6, [t, 'f'])
            t_is(lam['mu_l'], [0., 0., 0.], 13, [t, 'lam.mu_l'])
            t_is(lam['mu_u'], array([28., 4., 0.]) / 9, 7, [t, 'lam.mu_u'])
            t_is(lam['lower'], zeros(shape(x)), 8, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - constrained 4-d QP : ' % names[k]
            ## from http://www.jmu.edu/docs/sasdoc/sashtml/iml/chap8/sect12.htm
            H = sparse([[1003.1,  4.3,     6.3,     5.9],
                        [4.3,     2.2,     2.1,     3.9],
                        [6.3,     2.1,     3.5,     4.8],
                        [5.9,     3.9,     4.8,    10.0]])
            c = zeros(4)
            A = sparse([[   1,       1,       1,       1],
                        [0.17,    0.11,    0.10,    0.18]])
            l = array([1, 0.10])
            u = array([1, Inf])
            xmin = zeros(4)
            x0 = array([1, 0, 0, 1], float)
            x, f, s, _, lam = qps_pypower(H, c, A, l, u, xmin, None, x0, opt)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, array([0, 2.8, 0.2, 0]) / 3, 5, [t, 'x'])
            t_is(f, 3.29 / 3, 6, [t, 'f'])
            t_is(lam['mu_l'], array([6.58, 0]) / 3, 6, [t, 'lam.mu_l'])
            t_is(lam['mu_u'], [0, 0], 13, [t, 'lam.mu_u'])
            t_is(lam['lower'], [2.24, 0, 0, 1.7667], 4, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - (dict) constrained 4-d QP : ' % names[k]
            p = {'H': H, 'A': A, 'l': l, 'u': u, 'xmin': xmin, 'x0': x0, 'opt': opt}
            x, f, s, _, lam = qps_pypower(p)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, array([0, 2.8, 0.2, 0]) / 3, 5, [t, 'x'])
            t_is(f, 3.29 / 3, 6, [t, 'f'])
            t_is(lam['mu_l'], array([6.58, 0]) / 3, 6, [t, 'lam.mu_l'])
            t_is(lam['mu_u'], [0, 0], 13, [t, 'lam.mu_u'])
            t_is(lam['lower'], [2.24, 0, 0, 1.7667], 4, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - infeasible LP : ' % names[k]
            p = {'A': sparse([1, 1]), 'c': array([1, 1]), 'u': array([-1]),
                 'xmin': array([0, 0]), 'opt': opt}
            x, f, s, _, lam = qps_pypower(p)
            t_ok(s <= 0, [t, 'no success'])

    t_end()
コード例 #2
0
def dcopf_solver(om, ppopt, out_opt=None):
    """Solves a DC optimal power flow.

    Inputs are an OPF model object, a PYPOWER options dict and
    a dict containing fields (can be empty) for each of the desired
    optional output fields.

    Outputs are a C{results} dict, C{success} flag and C{raw} output dict.

    C{results} is a PYPOWER case dict (ppc) with the usual baseMVA, bus
    branch, gen, gencost fields, along with the following additional
    fields:
        - C{order}      see 'help ext2int' for details of this field
        - C{x}          final value of optimization variables (internal order)
        - C{f}          final objective function value
        - C{mu}         shadow prices on ...
            - C{var}
                - C{l}  lower bounds on variables
                - C{u}  upper bounds on variables
            - C{lin}
                - C{l}  lower bounds on linear constraints
                - C{u}  upper bounds on linear constraints
        - C{g}          (optional) constraint values
        - C{dg}         (optional) constraint 1st derivatives
        - C{df}         (optional) obj fun 1st derivatives (not yet implemented)
        - C{d2f}        (optional) obj fun 2nd derivatives (not yet implemented)

    C{success} is C{True} if solver converged successfully, C{False} otherwise.

    C{raw} is a raw output dict in form returned by MINOS
        - C{xr}     final value of optimization variables
        - C{pimul}  constraint multipliers
        - C{info}   solver specific termination code
        - C{output} solver specific output information

    @see: L{opf}, L{qps_pypower}

    @author: Ray Zimmerman (PSERC Cornell)
    @author: Carlos E. Murillo-Sanchez (PSERC Cornell & Universidad
    Autonoma de Manizales)
    @author: Richard Lincoln
    """
    if out_opt is None:
        out_opt = {}

    ## options
    verbose = ppopt['VERBOSE']
    alg = ppopt['OPF_ALG_DC']

    if alg == 0:
        if have_fcn('cplex'):  ## use CPLEX by default, if available
            alg = 500
        elif have_fcn('mosek'):  ## if not, then MOSEK, if available
            alg = 600
        elif have_fcn('gurobi'):  ## if not, then Gurobi, if available
            alg = 700
        else:  ## otherwise PIPS
            alg = 200

    ## unpack data
    ppc = om.get_ppc()
    baseMVA, bus, gen, branch, gencost = \
        ppc["baseMVA"], ppc["bus"], ppc["gen"], ppc["branch"], ppc["gencost"]
    cp = om.get_cost_params()
    N, H, Cw = cp["N"], cp["H"], cp["Cw"]
    fparm = array(c_[cp["dd"], cp["rh"], cp["kk"], cp["mm"]])
    Bf = om.userdata('Bf')
    Pfinj = om.userdata('Pfinj')
    vv, ll, _, _ = om.get_idx()

    ## problem dimensions
    ipol = find(gencost[:, MODEL] == POLYNOMIAL)  ## polynomial costs
    ipwl = find(gencost[:, MODEL] == PW_LINEAR)  ## piece-wise linear costs
    nb = bus.shape[0]  ## number of buses
    nl = branch.shape[0]  ## number of branches
    nw = N.shape[0]  ## number of general cost vars, w
    ny = om.getN('var', 'y')  ## number of piece-wise linear costs
    nxyz = om.getN('var')  ## total number of control vars of all types

    ## linear constraints & variable bounds
    A, l, u = om.linear_constraints()
    x0, xmin, xmax = om.getv()

    ## set up objective function of the form: f = 1/2 * X'*HH*X + CC'*X
    ## where X = [x;y;z]. First set up as quadratic function of w,
    ## f = 1/2 * w'*HHw*w + CCw'*w, where w = diag(M) * (N*X - Rhat). We
    ## will be building on the (optionally present) user supplied parameters.

    ## piece-wise linear costs
    any_pwl = int(ny > 0)
    if any_pwl:
        # Sum of y vars.
        Npwl = sparse(
            (ones(ny), (zeros(ny), arange(vv["i1"]["y"], vv["iN"]["y"]))),
            (1, nxyz))
        Hpwl = sparse((1, 1))
        Cpwl = array([1])
        fparm_pwl = array([[1, 0, 0, 1]])
    else:
        Npwl = None  #zeros((0, nxyz))
        Hpwl = None  #array([])
        Cpwl = array([])
        fparm_pwl = zeros((0, 4))

    ## quadratic costs
    npol = len(ipol)
    if any(find(gencost[ipol, NCOST] > 3)):
        stderr.write('DC opf cannot handle polynomial costs with higher '
                     'than quadratic order.\n')
    iqdr = find(gencost[ipol, NCOST] == 3)
    ilin = find(gencost[ipol, NCOST] == 2)
    polycf = zeros((npol, 3))  ## quadratic coeffs for Pg
    if len(iqdr) > 0:
        polycf[iqdr, :] = gencost[ipol[iqdr], COST:COST + 3]
    if npol:
        polycf[ilin, 1:3] = gencost[ipol[ilin], COST:COST + 2]
    polycf = dot(polycf, diag([baseMVA**2, baseMVA, 1]))  ## convert to p.u.
    if npol:
        Npol = sparse((ones(npol), (arange(npol), vv["i1"]["Pg"] + ipol)),
                      (npol, nxyz))  # Pg vars
        Hpol = sparse((2 * polycf[:, 0], (arange(npol), arange(npol))),
                      (npol, npol))
    else:
        Npol = None
        Hpol = None
    Cpol = polycf[:, 1]
    fparm_pol = ones((npol, 1)) * array([[1, 0, 0, 1]])

    ## combine with user costs
    NN = vstack(
        [n for n in [Npwl, Npol, N] if n is not None and n.shape[0] > 0],
        "csr")
    # FIXME: Zero dimension sparse matrices.
    if (Hpwl is not None) and any_pwl and (npol + nw):
        Hpwl = hstack([Hpwl, sparse((any_pwl, npol + nw))])
    if Hpol is not None:
        if any_pwl and npol:
            Hpol = hstack([sparse((npol, any_pwl)), Hpol])
        if npol and nw:
            Hpol = hstack([Hpol, sparse((npol, nw))])
    if (H is not None) and nw and (any_pwl + npol):
        H = hstack([sparse((nw, any_pwl + npol)), H])
    HHw = vstack(
        [h for h in [Hpwl, Hpol, H] if h is not None and h.shape[0] > 0],
        "csr")
    CCw = r_[Cpwl, Cpol, Cw]
    ffparm = r_[fparm_pwl, fparm_pol, fparm]

    ## transform quadratic coefficients for w into coefficients for X
    nnw = any_pwl + npol + nw
    M = sparse((ffparm[:, 3], (range(nnw), range(nnw))))
    MR = M * ffparm[:, 1]
    HMR = HHw * MR
    MN = M * NN
    HH = MN.T * HHw * MN
    CC = MN.T * (CCw - HMR)
    C0 = 0.5 * dot(MR, HMR) + sum(polycf[:, 2])  # Constant term of cost.

    ## set up input for QP solver
    opt = {'alg': alg, 'verbose': verbose}
    if (alg == 200) or (alg == 250):
        ## try to select an interior initial point
        Varefs = bus[bus[:, BUS_TYPE] == REF, VA] * (pi / 180.0)

        lb, ub = xmin.copy(), xmax.copy()
        lb[xmin == -Inf] = -1e10  ## replace Inf with numerical proxies
        ub[xmax == Inf] = 1e10
        x0 = (lb + ub) / 2
        # angles set to first reference angle
        x0[vv["i1"]["Va"]:vv["iN"]["Va"]] = Varefs[0]
        if ny > 0:
            ipwl = find(gencost[:, MODEL] == PW_LINEAR)
            # largest y-value in CCV data
            c = gencost.flatten('F')[sub2ind(gencost.shape, ipwl,
                                             NCOST + 2 * gencost[ipwl, NCOST])]
            x0[vv["i1"]["y"]:vv["iN"]["y"]] = max(c) + 0.1 * abs(max(c))

        ## set up options
        feastol = ppopt['PDIPM_FEASTOL']
        gradtol = ppopt['PDIPM_GRADTOL']
        comptol = ppopt['PDIPM_COMPTOL']
        costtol = ppopt['PDIPM_COSTTOL']
        max_it = ppopt['PDIPM_MAX_IT']
        max_red = ppopt['SCPDIPM_RED_IT']
        if feastol == 0:
            feastol = ppopt['OPF_VIOLATION']  ## = OPF_VIOLATION by default
        opt["pips_opt"] = {
            'feastol': feastol,
            'gradtol': gradtol,
            'comptol': comptol,
            'costtol': costtol,
            'max_it': max_it,
            'max_red': max_red,
            'cost_mult': 1
        }
    elif alg == 400:
        opt['ipopt_opt'] = ipopt_options([], ppopt)
    elif alg == 500:
        opt['cplex_opt'] = cplex_options([], ppopt)
    elif alg == 600:
        opt['mosek_opt'] = mosek_options([], ppopt)
    elif alg == 700:
        opt['grb_opt'] = gurobi_options([], ppopt)
    else:
        raise ValueError("Unrecognised solver [%d]." % alg)

    ##-----  run opf  -----
    x, f, info, output, lmbda = \
            qps_pypower(HH, CC, A, l, u, xmin, xmax, x0, opt)
    success = (info == 1)

    ##-----  calculate return values  -----
    if not any(isnan(x)):
        ## update solution data
        Va = x[vv["i1"]["Va"]:vv["iN"]["Va"]]
        Pg = x[vv["i1"]["Pg"]:vv["iN"]["Pg"]]
        f = f + C0

        ## update voltages & generator outputs
        bus[:, VA] = Va * 180 / pi
        gen[:, PG] = Pg * baseMVA

        ## compute branch flows
        branch[:, [QF, QT]] = zeros((nl, 2))
        branch[:, PF] = (Bf * Va + Pfinj) * baseMVA
        branch[:, PT] = -branch[:, PF]

    ## package up results
    mu_l = lmbda["mu_l"]
    mu_u = lmbda["mu_u"]
    muLB = lmbda["lower"]
    muUB = lmbda["upper"]

    ## update Lagrange multipliers
    il = find((branch[:, RATE_A] != 0) & (branch[:, RATE_A] < 1e10))
    bus[:, [LAM_P, LAM_Q, MU_VMIN, MU_VMAX]] = zeros((nb, 4))
    gen[:, [MU_PMIN, MU_PMAX, MU_QMIN, MU_QMAX]] = zeros((gen.shape[0], 4))
    branch[:, [MU_SF, MU_ST]] = zeros((nl, 2))
    bus[:, LAM_P] = (mu_u[ll["i1"]["Pmis"]:ll["iN"]["Pmis"]] -
                     mu_l[ll["i1"]["Pmis"]:ll["iN"]["Pmis"]]) / baseMVA
    branch[il, MU_SF] = mu_u[ll["i1"]["Pf"]:ll["iN"]["Pf"]] / baseMVA
    branch[il, MU_ST] = mu_u[ll["i1"]["Pt"]:ll["iN"]["Pt"]] / baseMVA
    gen[:, MU_PMIN] = muLB[vv["i1"]["Pg"]:vv["iN"]["Pg"]] / baseMVA
    gen[:, MU_PMAX] = muUB[vv["i1"]["Pg"]:vv["iN"]["Pg"]] / baseMVA

    pimul = r_[mu_l - mu_u, -ones(
        (ny > 0)),  ## dummy entry corresponding to linear cost row in A
               muLB - muUB]

    mu = {'var': {'l': muLB, 'u': muUB}, 'lin': {'l': mu_l, 'u': mu_u}}

    results = deepcopy(ppc)
    results["bus"], results["branch"], results["gen"], \
        results["om"], results["x"], results["mu"], results["f"] = \
            bus, branch, gen, om, x, mu, f

    raw = {'xr': x, 'pimul': pimul, 'info': info, 'output': output}

    return results, success, raw
コード例 #3
0
ファイル: qps_cplex.py プロジェクト: ink-corp/nonlinear-opt
def qps_cplex(H, c, A, l, u, xmin, xmax, x0, opt):
    """Quadratic Program Solver based on CPLEX.

    A wrapper function providing a PYPOWER standardized interface for using
    C{cplexqp} or C{cplexlp} to solve the following QP (quadratic programming)
    problem::

        min 1/2 X'*H*x + c'*x
         x

    subject to::

        l <= A*x <= u       (linear constraints)
        xmin <= x <= xmax   (variable bounds)

    Inputs (all optional except C{H}, C{c}, C{A} and C{l}):
        - C{H} : matrix (possibly sparse) of quadratic cost coefficients
        - C{c} : vector of linear cost coefficients
        - C{A, l, u} : define the optional linear constraints. Default
        values for the elements of L and U are -Inf and Inf, respectively.
        - C{xmin, xmax} : optional lower and upper bounds on the
        C{x} variables, defaults are -Inf and Inf, respectively.
        - C{x0} : optional starting value of optimization vector C{x}
        - C{opt} : optional options structure with the following fields,
        all of which are also optional (default values shown in parentheses)
            - C{verbose} (0) - controls level of progress output displayed
                - 0 = no progress output
                - 1 = some progress output
                - 2 = verbose progress output
            - C{cplex_opt} - options dict for CPLEX, value in
            verbose overrides these options
        - C{problem} : The inputs can alternatively be supplied in a single
        C{problem} dict with fields corresponding to the input arguments
        described above: C{H, c, A, l, u, xmin, xmax, x0, opt}

    Outputs:
        - C{x} : solution vector
        - C{f} : final objective function value
        - C{exitflag} : CPLEXQP/CPLEXLP exit flag
        (see C{cplexqp} and C{cplexlp} documentation for details)
        - C{output} : CPLEXQP/CPLEXLP output dict
        (see C{cplexqp} and C{cplexlp} documentation for details)
        - C{lmbda} : dict containing the Langrange and Kuhn-Tucker
        multipliers on the constraints, with fields:
            - mu_l - lower (left-hand) limit on linear constraints
            - mu_u - upper (right-hand) limit on linear constraints
            - lower - lower bound on optimization variables
            - upper - upper bound on optimization variables

    @author: Ray Zimmerman (PSERC Cornell)
    """
    ##----- input argument handling  -----
    ## gather inputs
    if isinstance(H, dict):  ## problem struct
        p = H
        if 'opt' in p: opt = p['opt']
        if 'x0' in p: x0 = p['x0']
        if 'xmax' in p: xmax = p['xmax']
        if 'xmin' in p: xmin = p['xmin']
        if 'u' in p: u = p['u']
        if 'l' in p: l = p['l']
        if 'A' in p: A = p['A']
        if 'c' in p: c = p['c']
        if 'H' in p: H = p['H']
    else:  ## individual args
        assert H is not None
        assert c is not None
        assert A is not None
        assert l is not None

    if opt is None:
        opt = {}
#    if x0 is None:
#        x0 = array([])
#    if xmax is None:
#        xmax = array([])
#    if xmin is None:
#        xmin = array([])

## define nx, set default values for missing optional inputs
    if len(H) == 0 or not any(any(H)):
        if len(A) == 0 and len(xmin) == 0 and len(xmax) == 0:
            stderr.write(
                'qps_cplex: LP problem must include constraints or variable bounds\n'
            )
        else:
            if len(A) > 0:
                nx = shape(A)[1]
            elif len(xmin) > 0:
                nx = len(xmin)
            else:  # if len(xmax) > 0
                nx = len(xmax)
    else:
        nx = shape(H)[0]

    if len(c) == 0:
        c = zeros(nx)

    if  len(A) > 0 and (len(l) == 0 or all(l == -Inf)) and \
                       (len(u) == 0 or all(u ==  Inf)):
        A = None  ## no limits => no linear constraints

    nA = shape(A)[0]  ## number of original linear constraints
    if len(u) == 0:  ## By default, linear inequalities are ...
        u = Inf * ones(nA)  ## ... unbounded above and ...

    if len(l) == 0:
        l = -Inf * ones(nA)  ## ... unbounded below.

    if len(xmin) == 0:  ## By default, optimization variables are ...
        xmin = -Inf * ones(nx)  ## ... unbounded below and ...

    if len(xmax) == 0:
        xmax = Inf * ones(nx)  ## ... unbounded above.

    if len(x0) == 0:
        x0 = zeros(nx)

    ## default options
    if 'verbose' in opt:
        verbose = opt['verbose']
    else:
        verbose = 0

    #if 'max_it' in opt:
    #    max_it = opt['max_it']
    #else:
    #    max_it = 0

    ## split up linear constraints
    ieq = find(abs(u - l) <= EPS)  ## equality
    igt = find(u >= 1e10 & l > -1e10)  ## greater than, unbounded above
    ilt = find(l <= -1e10 & u < 1e10)  ## less than, unbounded below
    ibx = find((abs(u - l) > EPS) & (u < 1e10) & (l > -1e10))
    Ae = A[ieq, :]
    be = u[ieq]
    Ai = r_[A[ilt, :], -A[igt, :], A[ibx, :] - A[ibx, :]]
    bi = r_[u[ilt], -l[igt], u[ibx], -l[ibx]]

    ## grab some dimensions
    nlt = len(ilt)  ## number of upper bounded linear inequalities
    ngt = len(igt)  ## number of lower bounded linear inequalities
    nbx = len(ibx)  ## number of doubly bounded linear inequalities

    ## set up options struct for CPLEX
    if 'cplex_opt' in opt:
        cplex_opt = cplex_options(opt['cplex_opt'])
    else:
        cplex_opt = cplex_options

    cplex = Cplex('null')
    vstr = cplex.getVersion
    s, e, tE, m, t = re.compile(vstr, '(\d+\.\d+)\.')
    vnum = int(t[0][0])
    vrb = max([0, verbose - 1])
    cplex_opt['barrier']['display'] = vrb
    cplex_opt['conflict']['display'] = vrb
    cplex_opt['mip']['display'] = vrb
    cplex_opt['sifting']['display'] = vrb
    cplex_opt['simplex']['display'] = vrb
    cplex_opt['tune']['display'] = vrb
    if vrb and (vnum > 12.2):
        cplex_opt['diagnostics'] = 'on'
    #if max_it:
    #    cplex_opt.    ## not sure what to set here

    if len(Ai) == 0 and len(Ae) == 0:
        unconstrained = 1
        Ae = sparse((1, nx))
        be = 0
    else:
        unconstrained = 0

    ## call the solver
    if verbose:
        methods = [
            'default', 'primal simplex', 'dual simplex', 'network simplex',
            'barrier', 'sifting', 'concurrent'
        ]

    if len(H) == 0 or not any(any(H)):
        if verbose:
            stdout.write('CPLEX Version %s -- %s LP solver\n' %
                         (vstr, methods[cplex_opt['lpmethod'] + 1]))

        x, f, eflag, output, lam = \
            cplexlp(c, Ai, bi, Ae, be, xmin, xmax, x0, cplex_opt)
    else:
        if verbose:
            stdout.write('CPLEX Version %s --  %s QP solver\n' %
                         (vstr, methods[cplex_opt['qpmethod'] + 1]))
        ## ensure H is numerically symmetric
        if H != H.T:
            H = (H + H.T) / 2

        x, f, eflag, output, lam = \
            cplexqp(H, c, Ai, bi, Ae, be, xmin, xmax, x0, cplex_opt)

    ## check for empty results (in case optimization failed)
    if len(x) == 0:
        x = NaN * zeros(nx)

    if len(f) == 0:
        f = NaN

    if len(lam) == 0:
        lam['ineqlin'] = NaN * zeros(len(bi))
        lam['eqlin'] = NaN * zeros(len(be))
        lam['lower'] = NaN * zeros(nx)
        lam['upper'] = NaN * zeros(nx)
        mu_l = NaN * zeros(nA)
        mu_u = NaN * zeros(nA)
    else:
        mu_l = zeros(nA)
        mu_u = zeros(nA)

    if unconstrained:
        lam['eqlin'] = array([])

    ## negate prices depending on version
    if vnum < 12.3:
        lam['eqlin'] = -lam['eqlin']
        lam['ineqlin'] = -lam['ineqlin']

    ## repackage lambdas
    kl = find(lam.eqlin < 0)  ## lower bound binding
    ku = find(lam.eqlin > 0)  ## upper bound binding

    mu_l[ieq[kl]] = -lam['eqlin'][kl]
    mu_l[igt] = lam['ineqlin'][nlt + arange(ngt)]
    mu_l[ibx] = lam['ineqlin'][nlt + ngt + nbx + arange(nbx)]

    mu_u[ieq[ku]] = lam['eqlin'][ku]
    mu_u[ilt] = lam['ineqlin'][:nlt]
    mu_u[ibx] = lam['ineqlin'][nlt + ngt + arange(nbx)]

    lmbda = {
        'mu_l': mu_l,
        'mu_u': mu_u,
        'lower': lam.lower,
        'upper': lam.upper
    }

    return x, f, eflag, output, lmbda
コード例 #4
0
ファイル: dcopf_solver.py プロジェクト: rwl/PYPOWER
def dcopf_solver(om, ppopt, out_opt=None):
    """Solves a DC optimal power flow.

    Inputs are an OPF model object, a PYPOWER options dict and
    a dict containing fields (can be empty) for each of the desired
    optional output fields.

    Outputs are a C{results} dict, C{success} flag and C{raw} output dict.

    C{results} is a PYPOWER case dict (ppc) with the usual baseMVA, bus
    branch, gen, gencost fields, along with the following additional
    fields:
        - C{order}      see 'help ext2int' for details of this field
        - C{x}          final value of optimization variables (internal order)
        - C{f}          final objective function value
        - C{mu}         shadow prices on ...
            - C{var}
                - C{l}  lower bounds on variables
                - C{u}  upper bounds on variables
            - C{lin}
                - C{l}  lower bounds on linear constraints
                - C{u}  upper bounds on linear constraints
        - C{g}          (optional) constraint values
        - C{dg}         (optional) constraint 1st derivatives
        - C{df}         (optional) obj fun 1st derivatives (not yet implemented)
        - C{d2f}        (optional) obj fun 2nd derivatives (not yet implemented)

    C{success} is C{True} if solver converged successfully, C{False} otherwise.

    C{raw} is a raw output dict in form returned by MINOS
        - C{xr}     final value of optimization variables
        - C{pimul}  constraint multipliers
        - C{info}   solver specific termination code
        - C{output} solver specific output information

    @see: L{opf}, L{qps_pypower}

    @author: Ray Zimmerman (PSERC Cornell)
    @author: Carlos E. Murillo-Sanchez (PSERC Cornell & Universidad
    Autonoma de Manizales)
    """
    if out_opt is None:
        out_opt = {}

    ## options
    verbose = ppopt['VERBOSE']
    alg     = ppopt['OPF_ALG_DC']

    if alg == 0:
        if have_fcn('cplex'):        ## use CPLEX by default, if available
            alg = 500
        elif have_fcn('mosek'):      ## if not, then MOSEK, if available
            alg = 600
        elif have_fcn('gurobi'):     ## if not, then Gurobi, if available
            alg = 700
        else:                        ## otherwise PIPS
            alg = 200

    ## unpack data
    ppc = om.get_ppc()
    baseMVA, bus, gen, branch, gencost = \
        ppc["baseMVA"], ppc["bus"], ppc["gen"], ppc["branch"], ppc["gencost"]
    cp = om.get_cost_params()
    N, H, Cw = cp["N"], cp["H"], cp["Cw"]
    fparm = array(c_[cp["dd"], cp["rh"], cp["kk"], cp["mm"]])
    Bf = om.userdata('Bf')
    Pfinj = om.userdata('Pfinj')
    vv, ll, _, _ = om.get_idx()

    ## problem dimensions
    ipol = find(gencost[:, MODEL] == POLYNOMIAL) ## polynomial costs
    ipwl = find(gencost[:, MODEL] == PW_LINEAR)  ## piece-wise linear costs
    nb = bus.shape[0]              ## number of buses
    nl = branch.shape[0]           ## number of branches
    nw = N.shape[0]                ## number of general cost vars, w
    ny = om.getN('var', 'y')       ## number of piece-wise linear costs
    nxyz = om.getN('var')          ## total number of control vars of all types

    ## linear constraints & variable bounds
    A, l, u = om.linear_constraints()
    x0, xmin, xmax = om.getv()

    ## set up objective function of the form: f = 1/2 * X'*HH*X + CC'*X
    ## where X = [x;y;z]. First set up as quadratic function of w,
    ## f = 1/2 * w'*HHw*w + CCw'*w, where w = diag(M) * (N*X - Rhat). We
    ## will be building on the (optionally present) user supplied parameters.

    ## piece-wise linear costs
    any_pwl = int(ny > 0)
    if any_pwl:
        # Sum of y vars.
        Npwl = sparse((ones(ny), (zeros(ny), arange(vv["i1"]["y"], vv["iN"]["y"]))), (1, nxyz))
        Hpwl = sparse((1, 1))
        Cpwl = array([1])
        fparm_pwl = array([[1, 0, 0, 1]])
    else:
        Npwl = None#zeros((0, nxyz))
        Hpwl = None#array([])
        Cpwl = array([])
        fparm_pwl = zeros((0, 4))

    ## quadratic costs
    npol = len(ipol)
    if any(find(gencost[ipol, NCOST] > 3)):
        stderr.write('DC opf cannot handle polynomial costs with higher '
                     'than quadratic order.\n')
    iqdr = find(gencost[ipol, NCOST] == 3)
    ilin = find(gencost[ipol, NCOST] == 2)
    polycf = zeros((npol, 3))         ## quadratic coeffs for Pg
    if len(iqdr) > 0:
        polycf[iqdr, :] = gencost[ipol[iqdr], COST:COST + 3]
    if npol:
        polycf[ilin, 1:3] = gencost[ipol[ilin], COST:COST + 2]
    polycf = dot(polycf, diag([ baseMVA**2, baseMVA, 1]))     ## convert to p.u.
    if npol:
        Npol = sparse((ones(npol), (arange(npol), vv["i1"]["Pg"] + ipol)),
                      (npol, nxyz))  # Pg vars
        Hpol = sparse((2 * polycf[:, 0], (arange(npol), arange(npol))),
                      (npol, npol))
    else:
        Npol = None
        Hpol = None
    Cpol = polycf[:, 1]
    fparm_pol = ones((npol, 1)) * array([[1, 0, 0, 1]])

    ## combine with user costs
    NN = vstack([n for n in [Npwl, Npol, N] if n is not None and n.shape[0] > 0], "csr")
    # FIXME: Zero dimension sparse matrices.
    if (Hpwl is not None) and any_pwl and (npol + nw):
        Hpwl = hstack([Hpwl, sparse((any_pwl, npol + nw))])
    if Hpol is not None:
        if any_pwl and npol:
            Hpol = hstack([sparse((npol, any_pwl)), Hpol])
        if npol and nw:
            Hpol = hstack([Hpol, sparse((npol, nw))])
    if (H is not None) and nw and (any_pwl + npol):
        H = hstack([sparse((nw, any_pwl + npol)), H])
    HHw = vstack([h for h in [Hpwl, Hpol, H] if h is not None and h.shape[0] > 0], "csr")
    CCw = r_[Cpwl, Cpol, Cw]
    ffparm = r_[fparm_pwl, fparm_pol, fparm]

    ## transform quadratic coefficients for w into coefficients for X
    nnw = any_pwl + npol + nw
    M = sparse((ffparm[:, 3], (range(nnw), range(nnw))))
    MR = M * ffparm[:, 1]
    HMR = HHw * MR
    MN = M * NN
    HH = MN.T * HHw * MN
    CC = MN.T * (CCw - HMR)
    C0 = 0.5 * dot(MR, HMR) + sum(polycf[:, 2])  # Constant term of cost.

    ## set up input for QP solver
    opt = {'alg': alg, 'verbose': verbose}
    if (alg == 200) or (alg == 250):
        ## try to select an interior initial point
        Varefs = bus[bus[:, BUS_TYPE] == REF, VA] * (pi / 180.0)

        lb, ub = xmin.copy(), xmax.copy()
        lb[xmin == -Inf] = -1e10   ## replace Inf with numerical proxies
        ub[xmax ==  Inf] =  1e10
        x0 = (lb + ub) / 2;
        # angles set to first reference angle
        x0[vv["i1"]["Va"]:vv["iN"]["Va"]] = Varefs[0]
        if ny > 0:
            ipwl = find(gencost[:, MODEL] == PW_LINEAR)
            # largest y-value in CCV data
            c = gencost.flatten('F')[sub2ind(gencost.shape, ipwl,
                                NCOST + 2 * gencost[ipwl, NCOST])]
            x0[vv["i1"]["y"]:vv["iN"]["y"]] = max(c) + 0.1 * abs(max(c))

        ## set up options
        feastol = ppopt['PDIPM_FEASTOL']
        gradtol = ppopt['PDIPM_GRADTOL']
        comptol = ppopt['PDIPM_COMPTOL']
        costtol = ppopt['PDIPM_COSTTOL']
        max_it  = ppopt['PDIPM_MAX_IT']
        max_red = ppopt['SCPDIPM_RED_IT']
        if feastol == 0:
            feastol = ppopt['OPF_VIOLATION']    ## = OPF_VIOLATION by default
        opt["pips_opt"] = {  'feastol': feastol,
                             'gradtol': gradtol,
                             'comptol': comptol,
                             'costtol': costtol,
                             'max_it':  max_it,
                             'max_red': max_red,
                             'cost_mult': 1  }
    elif alg == 400:
        opt['ipopt_opt'] = ipopt_options([], ppopt)
    elif alg == 500:
        opt['cplex_opt'] = cplex_options([], ppopt)
    elif alg == 600:
        opt['mosek_opt'] = mosek_options([], ppopt)
    elif alg == 700:
        opt['grb_opt'] = gurobi_options([], ppopt)
    else:
        raise ValueError("Unrecognised solver [%d]." % alg)

    ##-----  run opf  -----
    x, f, info, output, lmbda = \
            qps_pypower(HH, CC, A, l, u, xmin, xmax, x0, opt)
    success = (info == 1)

    ##-----  calculate return values  -----
    if not any(isnan(x)):
        ## update solution data
        Va = x[vv["i1"]["Va"]:vv["iN"]["Va"]]
        Pg = x[vv["i1"]["Pg"]:vv["iN"]["Pg"]]
        f = f + C0

        ## update voltages & generator outputs
        bus[:, VA] = Va * 180 / pi
        gen[:, PG] = Pg * baseMVA

        ## compute branch flows
        branch[:, [QF, QT]] = zeros((nl, 2))
        branch[:, PF] = (Bf * Va + Pfinj) * baseMVA
        branch[:, PT] = -branch[:, PF]

    ## package up results
    mu_l = lmbda["mu_l"]
    mu_u = lmbda["mu_u"]
    muLB = lmbda["lower"]
    muUB = lmbda["upper"]

    ## update Lagrange multipliers
    il = find((branch[:, RATE_A] != 0) & (branch[:, RATE_A] < 1e10))
    bus[:, [LAM_P, LAM_Q, MU_VMIN, MU_VMAX]] = zeros((nb, 4))
    gen[:, [MU_PMIN, MU_PMAX, MU_QMIN, MU_QMAX]] = zeros((gen.shape[0], 4))
    branch[:, [MU_SF, MU_ST]] = zeros((nl, 2))
    bus[:, LAM_P]       = (mu_u[ll["i1"]["Pmis"]:ll["iN"]["Pmis"]] -
                           mu_l[ll["i1"]["Pmis"]:ll["iN"]["Pmis"]]) / baseMVA
    branch[il, MU_SF]   = mu_u[ll["i1"]["Pf"]:ll["iN"]["Pf"]] / baseMVA
    branch[il, MU_ST]   = mu_u[ll["i1"]["Pt"]:ll["iN"]["Pt"]] / baseMVA
    gen[:, MU_PMIN]     = muLB[vv["i1"]["Pg"]:vv["iN"]["Pg"]] / baseMVA
    gen[:, MU_PMAX]     = muUB[vv["i1"]["Pg"]:vv["iN"]["Pg"]] / baseMVA

    pimul = r_[
      mu_l - mu_u,
     -ones(int(ny > 0)), ## dummy entry corresponding to linear cost row in A
      muLB - muUB
    ]

    mu = { 'var': {'l': muLB, 'u': muUB},
           'lin': {'l': mu_l, 'u': mu_u} }

    results = deepcopy(ppc)
    results["bus"], results["branch"], results["gen"], \
        results["om"], results["x"], results["mu"], results["f"] = \
            bus, branch, gen, om, x, mu, f

    raw = {'xr': x, 'pimul': pimul, 'info': info, 'output': output}

    return results, success, raw
コード例 #5
0
ファイル: t_qps_pypower.py プロジェクト: redw0lf/PYPOWER
def t_qps_pypower(quiet=False):
    """Tests of C{qps_pypower} QP solvers.

    @author: Ray Zimmerman (PSERC Cornell)
    @author: Richard Lincoln
    """
    algs = [200, 250, 400, 500, 600, 700]
    names = ['PIPS', 'sc-PIPS', 'IPOPT', 'CPLEX', 'MOSEK', 'Gurobi']
    check = [None, None, 'ipopt', 'cplex', 'mosek', 'gurobipy']

    n = 36
    t_begin(n * len(algs), quiet)

    for k in range(len(algs)):
        if check[k] is not None and not have_fcn(check[k]):
            t_skip(n, '%s not installed' % names[k])
        else:
            opt = {'verbose': 0, 'alg': algs[k]}

            if names[k] == 'PIPS' or names[k] == 'sc-PIPS':
                opt['pips_opt'] = {}
                opt['pips_opt']['comptol'] = 1e-8
            if names[k] == 'CPLEX':
                #               alg = 0        ## default uses barrier method with NaN bug in lower lim multipliers
                alg = 2  ## use dual simplex
                ppopt = ppoption(CPLEX_LPMETHOD=alg,
                                 CPLEX_QPMETHOD=min([4, alg]))
                opt['cplex_opt'] = cplex_options([], ppopt)

            if names[k] == 'MOSEK':
                #                alg = 5        ## use dual simplex
                ppopt = ppoption()
                #                ppopt = ppoption(ppopt, MOSEK_LP_ALG = alg)
                ppopt = ppoption(ppopt, MOSEK_GAP_TOL=1e-9)
                opt['mosek_opt'] = mosek_options([], ppopt)

            t = '%s - 3-d LP : ' % names[k]
            ## example from 'doc linprog'
            c = array([-5, -4, -6], float)
            A = sparse([[1, -1, 1], [3, 2, 4], [3, 2, 0]], dtype=float)
            l = None
            u = array([20, 42, 30], float)
            xmin = array([0, 0, 0], float)
            x0 = None
            x, f, s, _, lam = qps_pypower(None, c, A, l, u, xmin, None, None,
                                          opt)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, [0, 15, 3], 6, [t, 'x'])
            t_is(f, -78, 6, [t, 'f'])
            t_is(lam['mu_l'], [0, 0, 0], 13, [t, 'lam.mu_l'])
            t_is(lam['mu_u'], [0, 1.5, 0.5], 9, [t, 'lam.mu_u'])
            t_is(lam['lower'], [1, 0, 0], 9, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - unconstrained 3-d quadratic : ' % names[k]
            ## from http://www.akiti.ca/QuadProgEx0Constr.html
            H = sparse([[5, -2, -1], [-2, 4, 3], [-1, 3, 5]], dtype=float)
            c = array([2, -35, -47], float)
            x0 = array([0, 0, 0], float)
            x, f, s, _, lam = qps_pypower(H, c, opt=opt)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, [3, 5, 7], 8, [t, 'x'])
            t_is(f, -249, 13, [t, 'f'])
            t_ok(len(lam['mu_l']) == 0, [t, 'lam.mu_l'])
            t_ok(len(lam['mu_u']) == 0, [t, 'lam.mu_u'])
            t_is(lam['lower'], zeros(shape(x)), 13, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - constrained 2-d QP : ' % names[k]
            ## example from 'doc quadprog'
            H = sparse([[1, -1], [-1, 2]], dtype=float)
            c = array([-2, -6], float)
            A = sparse([[1, 1], [-1, 2], [2, 1]], dtype=float)
            l = None
            u = array([2, 2, 3], float)
            xmin = array([0, 0])
            x0 = None
            x, f, s, _, lam = qps_pypower(H, c, A, l, u, xmin, None, x0, opt)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, array([2., 4.]) / 3, 7, [t, 'x'])
            t_is(f, -74. / 9, 6, [t, 'f'])
            t_is(lam['mu_l'], [0., 0., 0.], 13, [t, 'lam.mu_l'])
            t_is(lam['mu_u'], array([28., 4., 0.]) / 9, 7, [t, 'lam.mu_u'])
            t_is(lam['lower'], zeros(shape(x)), 8, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - constrained 4-d QP : ' % names[k]
            ## from http://www.jmu.edu/docs/sasdoc/sashtml/iml/chap8/sect12.htm
            H = sparse([[1003.1, 4.3, 6.3, 5.9], [4.3, 2.2, 2.1, 3.9],
                        [6.3, 2.1, 3.5, 4.8], [5.9, 3.9, 4.8, 10.0]])
            c = zeros(4)
            A = sparse([[1, 1, 1, 1], [0.17, 0.11, 0.10, 0.18]])
            l = array([1, 0.10])
            u = array([1, Inf])
            xmin = zeros(4)
            x0 = array([1, 0, 0, 1], float)
            x, f, s, _, lam = qps_pypower(H, c, A, l, u, xmin, None, x0, opt)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, array([0, 2.8, 0.2, 0]) / 3, 5, [t, 'x'])
            t_is(f, 3.29 / 3, 6, [t, 'f'])
            t_is(lam['mu_l'], array([6.58, 0]) / 3, 6, [t, 'lam.mu_l'])
            t_is(lam['mu_u'], [0, 0], 13, [t, 'lam.mu_u'])
            t_is(lam['lower'], [2.24, 0, 0, 1.7667], 4, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - (dict) constrained 4-d QP : ' % names[k]
            p = {
                'H': H,
                'A': A,
                'l': l,
                'u': u,
                'xmin': xmin,
                'x0': x0,
                'opt': opt
            }
            x, f, s, _, lam = qps_pypower(p)
            t_is(s, 1, 12, [t, 'success'])
            t_is(x, array([0, 2.8, 0.2, 0]) / 3, 5, [t, 'x'])
            t_is(f, 3.29 / 3, 6, [t, 'f'])
            t_is(lam['mu_l'], array([6.58, 0]) / 3, 6, [t, 'lam.mu_l'])
            t_is(lam['mu_u'], [0, 0], 13, [t, 'lam.mu_u'])
            t_is(lam['lower'], [2.24, 0, 0, 1.7667], 4, [t, 'lam.lower'])
            t_is(lam['upper'], zeros(shape(x)), 13, [t, 'lam.upper'])

            t = '%s - infeasible LP : ' % names[k]
            p = {
                'A': sparse([1, 1]),
                'c': array([1, 1]),
                'u': array([-1]),
                'xmin': array([0, 0]),
                'opt': opt
            }
            x, f, s, _, lam = qps_pypower(p)
            t_ok(s <= 0, [t, 'no success'])

    t_end()
コード例 #6
0
ファイル: qps_cplex.py プロジェクト: charlie0389/PYPOWER
def qps_cplex(H, c, A, l, u, xmin, xmax, x0, opt):
    """Quadratic Program Solver based on CPLEX.

    A wrapper function providing a PYPOWER standardized interface for using
    C{cplexqp} or C{cplexlp} to solve the following QP (quadratic programming)
    problem::

        min 1/2 X'*H*x + c'*x
         x

    subject to::

        l <= A*x <= u       (linear constraints)
        xmin <= x <= xmax   (variable bounds)

    Inputs (all optional except C{H}, C{c}, C{A} and C{l}):
        - C{H} : matrix (possibly sparse) of quadratic cost coefficients
        - C{c} : vector of linear cost coefficients
        - C{A, l, u} : define the optional linear constraints. Default
        values for the elements of L and U are -Inf and Inf, respectively.
        - C{xmin, xmax} : optional lower and upper bounds on the
        C{x} variables, defaults are -Inf and Inf, respectively.
        - C{x0} : optional starting value of optimization vector C{x}
        - C{opt} : optional options structure with the following fields,
        all of which are also optional (default values shown in parentheses)
            - C{verbose} (0) - controls level of progress output displayed
                - 0 = no progress output
                - 1 = some progress output
                - 2 = verbose progress output
            - C{cplex_opt} - options dict for CPLEX, value in
            verbose overrides these options
        - C{problem} : The inputs can alternatively be supplied in a single
        C{problem} dict with fields corresponding to the input arguments
        described above: C{H, c, A, l, u, xmin, xmax, x0, opt}

    Outputs:
        - C{x} : solution vector
        - C{f} : final objective function value
        - C{exitflag} : CPLEXQP/CPLEXLP exit flag
        (see C{cplexqp} and C{cplexlp} documentation for details)
        - C{output} : CPLEXQP/CPLEXLP output dict
        (see C{cplexqp} and C{cplexlp} documentation for details)
        - C{lmbda} : dict containing the Langrange and Kuhn-Tucker
        multipliers on the constraints, with fields:
            - mu_l - lower (left-hand) limit on linear constraints
            - mu_u - upper (right-hand) limit on linear constraints
            - lower - lower bound on optimization variables
            - upper - upper bound on optimization variables

    @author: Ray Zimmerman (PSERC Cornell)
    @author: Richard Lincoln
    """
    ##----- input argument handling  -----
    ## gather inputs
    if isinstance(H, dict):       ## problem struct
        p = H
        if 'opt' in p: opt = p['opt']
        if 'x0' in p: x0 = p['x0']
        if 'xmax' in p: xmax = p['xmax']
        if 'xmin' in p: xmin = p['xmin']
        if 'u' in p: u = p['u']
        if 'l' in p: l = p['l']
        if 'A' in p: A = p['A']
        if 'c' in p: c = p['c']
        if 'H' in p: H = p['H']
    else:                         ## individual args
        assert H is not None
        assert c is not None
        assert A is not None
        assert l is not None

    if opt is None:
        opt = {}
#    if x0 is None:
#        x0 = array([])
#    if xmax is None:
#        xmax = array([])
#    if xmin is None:
#        xmin = array([])

    ## define nx, set default values for missing optional inputs
    if len(H) == 0 or not any(any(H)):
        if len(A) == 0 and len(xmin) == 0 and len(xmax) == 0:
            stderr.write('qps_cplex: LP problem must include constraints or variable bounds\n')
        else:
            if len(A) > 0:
                nx = shape(A)[1]
            elif len(xmin) > 0:
                nx = len(xmin)
            else:    # if len(xmax) > 0
                nx = len(xmax)
    else:
        nx = shape(H)[0]

    if len(c) == 0:
        c = zeros(nx)

    if  len(A) > 0 and (len(l) == 0 or all(l == -Inf)) and \
                       (len(u) == 0 or all(u ==  Inf)):
        A = None                    ## no limits => no linear constraints

    nA = shape(A)[0]                ## number of original linear constraints
    if len(u) == 0:                 ## By default, linear inequalities are ...
        u = Inf * ones(nA)          ## ... unbounded above and ...

    if len(l) == 0:
        l = -Inf * ones(nA)         ## ... unbounded below.

    if len(xmin) == 0:              ## By default, optimization variables are ...
        xmin = -Inf * ones(nx)      ## ... unbounded below and ...

    if len(xmax) == 0:
        xmax = Inf * ones(nx)       ## ... unbounded above.

    if len(x0) == 0:
        x0 = zeros(nx)

    ## default options
    if 'verbose' in opt:
        verbose = opt['verbose']
    else:
        verbose = 0

    #if 'max_it' in opt:
    #    max_it = opt['max_it']
    #else:
    #    max_it = 0

    ## split up linear constraints
    ieq = find( abs(u-l) <= EPS )           ## equality
    igt = find( u >=  1e10 & l > -1e10 )    ## greater than, unbounded above
    ilt = find( l <= -1e10 & u <  1e10 )    ## less than, unbounded below
    ibx = find( (abs(u-l) > EPS) & (u < 1e10) & (l > -1e10) )
    Ae = A[ieq, :]
    be = u[ieq]
    Ai  = r_[ A[ilt, :], -A[igt, :], A[ibx, :] -A[ibx, :] ]
    bi  = r_[ u[ilt],    -l[igt],    u[ibx],   -l[ibx]    ]

    ## grab some dimensions
    nlt = len(ilt)      ## number of upper bounded linear inequalities
    ngt = len(igt)      ## number of lower bounded linear inequalities
    nbx = len(ibx)      ## number of doubly bounded linear inequalities

    ## set up options struct for CPLEX
    if 'cplex_opt' in opt:
        cplex_opt = cplex_options(opt['cplex_opt'])
    else:
        cplex_opt = cplex_options


    cplex = Cplex('null')
    vstr = cplex.getVersion
    s, e, tE, m, t = re.compile(vstr, '(\d+\.\d+)\.')
    vnum = int(t[0][0])
    vrb = max([0, verbose - 1])
    cplex_opt['barrier']['display']   = vrb
    cplex_opt['conflict']['display']  = vrb
    cplex_opt['mip']['display']       = vrb
    cplex_opt['sifting']['display']   = vrb
    cplex_opt['simplex']['display']   = vrb
    cplex_opt['tune']['display']      = vrb
    if vrb and (vnum > 12.2):
        cplex_opt['diagnostics']   = 'on'
    #if max_it:
    #    cplex_opt.    ## not sure what to set here

    if len(Ai) == 0 and len(Ae) == 0:
        unconstrained = 1
        Ae = sparse((1, nx))
        be = 0
    else:
        unconstrained = 0

    ## call the solver
    if verbose:
        methods = [
            'default',
            'primal simplex',
            'dual simplex',
            'network simplex',
            'barrier',
            'sifting',
            'concurrent'
        ]

    if len(H) == 0 or not any(any(H)):
        if verbose:
            stdout.write('CPLEX Version %s -- %s LP solver\n' %
                (vstr, methods[cplex_opt['lpmethod'] + 1]))

        x, f, eflag, output, lam = \
            cplexlp(c, Ai, bi, Ae, be, xmin, xmax, x0, cplex_opt)
    else:
        if verbose:
            stdout.write('CPLEX Version %s --  %s QP solver\n' %
                (vstr, methods[cplex_opt['qpmethod'] + 1]))
        ## ensure H is numerically symmetric
        if H != H.T:
            H = (H + H.T) / 2

        x, f, eflag, output, lam = \
            cplexqp(H, c, Ai, bi, Ae, be, xmin, xmax, x0, cplex_opt)


    ## check for empty results (in case optimization failed)
    if len(x) == 0:
        x = NaN * zeros(nx)

    if len(f) == 0:
        f = NaN

    if len(lam) == 0:
        lam['ineqlin'] = NaN * zeros(len(bi))
        lam['eqlin']   = NaN * zeros(len(be))
        lam['lower']   = NaN * zeros(nx)
        lam['upper']   = NaN * zeros(nx)
        mu_l        = NaN * zeros(nA)
        mu_u        = NaN * zeros(nA)
    else:
        mu_l        = zeros(nA)
        mu_u        = zeros(nA)

    if unconstrained:
        lam['eqlin'] = array([])

    ## negate prices depending on version
    if vnum < 12.3:
        lam['eqlin']   = -lam['eqlin']
        lam['ineqlin'] = -lam['ineqlin']

    ## repackage lambdas
    kl = find(lam.eqlin < 0)   ## lower bound binding
    ku = find(lam.eqlin > 0)   ## upper bound binding

    mu_l[ieq[kl]] = -lam['eqlin'][kl]
    mu_l[igt] = lam['ineqlin'][nlt + arange(ngt)]
    mu_l[ibx] = lam['ineqlin'][nlt + ngt + nbx + arange(nbx)]

    mu_u[ieq[ku]] = lam['eqlin'][ku]
    mu_u[ilt] = lam['ineqlin'][:nlt]
    mu_u[ibx] = lam['ineqlin'][nlt + ngt + arange(nbx)]

    lmbda = {
        'mu_l': mu_l,
        'mu_u': mu_u,
        'lower': lam.lower,
        'upper': lam.upper
    }

    return x, f, eflag, output, lmbda