Beispiel #1
0
def test_1dmog(mus=[-2., 2.], sigs=[1., np.sqrt(3.)], pis=[0.5, 0.5], deg = 3, obsdeg = 6):
    print 'testing 1d mixture of Gaussians'
    # constraints on parameters here
    
    K = len(mus)
    mu,sig = sp.symbols('mu,sigma')
    M = mm.MomentMatrix(deg, [mu, sig], morder='grevlex')

    num_constrs = obsdeg + 1; # so observe num_constrs-1 moments
    H = abs(hermite_coeffs(num_constrs))
    constrs = [0]*num_constrs
    
    for order in range(num_constrs):
        for i in range(order+1):
            constrs[order] = constrs[order] + H[order,i]* mu**(i) * sig**(order-i)
        constrsval = 0
        for k in range(K):
            constrsval += pis[k]*constrs[order].evalf(subs={mu:mus[k], sig:sigs[k]})
        constrs[order] -= constrsval
    print constrs
    cin = M.get_cvxopt_inputs(constrs[1:])

    gs = [sig-0.2, 5-sig, sig+5, 10-mu, mu+10]
    #gs = [sig-0.2]
    locmatrices = [mm.LocalizingMatrix(M, g) for g in gs]
    Ghs = [lm.get_cvxopt_Gh() for lm in locmatrices]

    Gs=cin['G']# + [Gh['G'] for Gh in Ghs]
    hs=cin['h']# + [Gh['h'] for Gh in Ghs]
    
    sol = solvers.sdp(cin['c'],Gs=Gs, \
                  hs=hs, A=cin['A'], b=cin['b'])

    
    ## Q = cin['A'].T*cin['A']
    ## weight = 1;
    ## dims = {}
    ## dims['l'] = 0; dims['q'] = []; dims['s'] = [len(M.row_monos)]
    ## ipdb.set_trace()
    ## sol = solvers.coneqp(Q*weight, cin['A'].T*cin['b']*weight + cin['c'],G=Gs[0], \
    ##               h=hs[0][:], dims = dims, A=cin['A'], b=cin['b'])

    for i,mono in enumerate(M.matrix_monos):
        trueval = 0;
        if i>0:
            for k in range(K):
                trueval += pis[k]*mono.evalf(subs={mu:mus[k], sig:sigs[k]})
        else:
            trueval = 1
        print '%s:\t%f\t%f' % (str(mono), sol['x'][i], trueval)
    print M.extract_solutions_lasserre(sol['x'], Kmax=len(mus))
    #import MomentMatrixSolver as mmsolver
    #print mmsolver.alternating_solver(M, constrs, 2, maxiter=30000)
    return M,sol
Beispiel #2
0
 def polymom_univariate(xi, c, order):
     constr = 0
     H = abs(hermite_coeffs(order+1))
     for i in range(order+1):
         constr = constr + H[order,i]* xi**(i) * c**((order-i)/2)
     return constr
def test_1dmog(mus=[-2., 2.],
               sigs=[1., np.sqrt(3.)],
               pis=[0.5, 0.5],
               deg=3,
               obsdeg=6):
    print 'testing 1d mixture of Gaussians'
    # constraints on parameters here

    K = len(mus)
    mu, sig = sp.symbols('mu,sigma')
    M = mm.MomentMatrix(deg, [mu, sig], morder='grevlex')

    num_constrs = obsdeg + 1
    # so observe num_constrs-1 moments
    H = abs(hermite_coeffs(num_constrs))
    constrs = [0] * num_constrs

    for order in range(num_constrs):
        for i in range(order + 1):
            constrs[order] = constrs[order] + H[order,
                                                i] * mu**(i) * sig**(order - i)
        constrsval = 0
        for k in range(K):
            constrsval += pis[k] * constrs[order].evalf(subs={
                mu: mus[k],
                sig: sigs[k]
            })
        constrs[order] -= constrsval
    print constrs
    cin = M.get_cvxopt_inputs(constrs[1:])

    gs = [sig - 0.2, 5 - sig, sig + 5, 10 - mu, mu + 10]
    #gs = [sig-0.2]
    locmatrices = [mm.LocalizingMatrix(M, g) for g in gs]
    Ghs = [lm.get_cvxopt_Gh() for lm in locmatrices]

    Gs = cin['G']  # + [Gh['G'] for Gh in Ghs]
    hs = cin['h']  # + [Gh['h'] for Gh in Ghs]

    sol = solvers.sdp(cin['c'],Gs=Gs, \
                  hs=hs, A=cin['A'], b=cin['b'])

    ## Q = cin['A'].T*cin['A']
    ## weight = 1;
    ## dims = {}
    ## dims['l'] = 0; dims['q'] = []; dims['s'] = [len(M.row_monos)]
    ## ipdb.set_trace()
    ## sol = solvers.coneqp(Q*weight, cin['A'].T*cin['b']*weight + cin['c'],G=Gs[0], \
    ##               h=hs[0][:], dims = dims, A=cin['A'], b=cin['b'])

    for i, mono in enumerate(M.matrix_monos):
        trueval = 0
        if i > 0:
            for k in range(K):
                trueval += pis[k] * mono.evalf(subs={mu: mus[k], sig: sigs[k]})
        else:
            trueval = 1
        print '%s:\t%f\t%f' % (str(mono), sol['x'][i], trueval)
    print M.extract_solutions_lasserre(sol['x'], Kmax=len(mus))
    #import MomentMatrixSolver as mmsolver
    #print mmsolver.alternating_solver(M, constrs, 2, maxiter=30000)
    return M, sol