Ejemplo n.º 1
0
class EstStats(ExpSwitcher):
    ''' 
        A simple agent that estimates various statistics 
        of the observations. 
    '''

    def init(self, boot_spec):
        ExpSwitcher.init(self, boot_spec)
        if len(boot_spec.get_observations().shape()) != 1:
            raise UnsupportedSpec('I assume 1D signals.')

        self.y_stats = MeanCovariance()

    def merge(self, other):
        self.y_stats.merge(other.y_stats)
   
   
    def process_observations(self, obs):
        y = obs['observations']
        dt = obs['dt'].item()
        self.y_stats.update(y, dt)

    def get_state(self):
        return dict(y_stats=self.y_stats)

    def set_state(self, state):
        self.y_stats = state['y_stats']

    def publish(self, pub):
        if self.y_stats.get_num_samples() == 0:
            pub.text('warning', 'Too early to publish anything.')
            return
        Py = self.y_stats.get_covariance()
        Ry = self.y_stats.get_correlation()
        Py_inv = self.y_stats.get_information()
        Ey = self.y_stats.get_mean()
        y_max = self.y_stats.get_maximum()
        y_min = self.y_stats.get_minimum()

        Ry0 = Ry.copy()
        np.fill_diagonal(Ry0, np.NaN)
        Py0 = Py.copy()
        np.fill_diagonal(Py0, np.NaN)

        pub.text('stats', 'Num samples: %s' % self.y_stats.get_num_samples())

        with pub.plot('y_bounds') as pylab:
            style_ieee_fullcol_xy(pylab)
            pylab.plot(Ey, label='E(y)')
            pylab.plot(y_max, label='y_max')
            pylab.plot(y_min, label='y_min')
            pylab.legend()

        all_positive = (np.min(Ey) > 0
                        and np.min(y_max) > 0
                        and np.min(y_min) > 0)
        if all_positive:
            with pub.plot('y_stats_log') as pylab:
                style_ieee_fullcol_xy(pylab)
                pylab.semilogy(Ey, label='E(y)')
                pylab.semilogy(y_max, label='y_max')
                pylab.semilogy(y_min, label='y_min')
                pylab.legend()

        pub.array_as_image('Py', Py, caption='cov(y)')
        pub.array_as_image('Py0', Py0, caption='cov(y) - no diagonal')

        pub.array_as_image('Ry', Ry, caption='corr(y)')
        pub.array_as_image('Ry0', Ry0, caption='corr(y) - no diagonal')

        pub.array_as_image('Py_inv', Py_inv)
        pub.array_as_image('Py_inv_n', cov2corr(Py_inv))

        with pub.plot('Py_svd') as pylab:  # XXX: use spectrum
            style_ieee_fullcol_xy(pylab)
            _, s, _ = np.linalg.svd(Py)
            s /= s[0]
            pylab.semilogy(s, 'bx-')

        with pub.subsection('y_stats') as sub:
            self.y_stats.publish(sub)
Ejemplo n.º 2
0
class BDSEEstimator(BDSEEstimatorInterface):
    """
        Estimates a BDSE model.
        
        Tensors used: ::
        
            M^s_vi   (N) x (N x K)
            N^s_i    (N) x (K)
            T^svi    (NxNxK)
            U^si     (NxK)
    
    """

    @contract(rcond='float,>0')
    def __init__(self, rcond=1e-10, antisym_T=False, antisym_M=False, use_P_scaling=False):
        """
            :param rcond: Threshold for computing pseudo-inverse of P.
            :param antisym_T: If True, the estimate of T is antisymmetrized.
            :param antisym_M: If True, the estimate of M is antisymmetrized.
        """
        self.rcond = rcond
        self.antisym_M = antisym_M
        self.antisym_T = antisym_T
        self.use_P_scaling = use_P_scaling
        self.info('rcond: %f' % rcond)
        self.info('antisym_T: %s' % antisym_T)
        self.info('antisym_M: %s' % antisym_M)
        self.info('use_P_scaling: %s' % use_P_scaling)

        self.T = Expectation()
        self.U = Expectation()
        self.y_stats = MeanCovariance()
        self.u_stats = MeanCovariance()
        self.nsamples = 0
        self.once = False
        
    def merge(self, other):
        assert isinstance(other, BDSEEstimator)
        self.T.merge(other.T)
        self.U.merge(other.U)
        self.y_stats.merge(other.y_stats)
        self.u_stats.merge(other.u_stats)
        self.nsamples += other.nsamples
    
    @contract(u='array[K],K>0,finite',
              y='array[N],N>0,finite',
              y_dot='array[N],finite', w='>0')
    def update(self, y, u, y_dot, w=1.0):
        self.once = True
        self.nsamples += 1
        
        self.n = y.size
        self.k = u.size  # XXX: check

        self.y_stats.update(y, w)
        self.u_stats.update(u, w)
        
        # remove mean
        u_n = u - self.u_stats.get_mean()
        y_n = y - self.y_stats.get_mean()
        
        # make products
        T_k = outer(outer(y_n, y_dot), u_n)
        assert T_k.shape == (self.n, self.n, self.k)
        
        U_k = outer(y_dot, u_n)
        assert U_k.shape == (self.n, self.k)
        
        # update tensor
        self.T.update(T_k, w)
        self.U.update(U_k, w)

    def get_P_inv_cond(self):
        P = self.y_stats.get_covariance()
        if False:
            P_inv = np.linalg.pinv(P, rcond=self.rcond)
        if True:
            P2 = P + np.eye(P.shape[0]) * self.rcond
            P_inv = np.linalg.inv(P2)
        return P_inv

    def get_T(self):
        T = self.T.get_value()
        if self.antisym_T:
            self.info('antisymmetrizing T')
            T = antisym(T)
        return T
    
    def get_model(self):
        T = self.get_T()
            
        U = self.U.get_value()
        P = self.y_stats.get_covariance()
        Q = self.u_stats.get_covariance()

        P_inv = self.get_P_inv_cond()
        Q_inv = np.linalg.pinv(Q)

        if False:
            M = get_M_from_P_T_Q(P, T, Q)
        else:
            if hasattr(self, 'use_P_scaling') and self.use_P_scaling:
                M = get_M_from_P_T_Q_alt_scaling(P, T, Q)
            else:
                warnings.warn('untested')
                try:
                    M = get_M_from_Pinv_T_Q(P_inv, T, Q)
                except LinAlgError as e:
                    msg = 'Could not get_M_from_Pinv_T_Q.\n'
                    msg += indent(traceback.format_exc(e), '> ')
                    raise BDSEEstimatorInterface.NotReady(msg)
        
        UQ_inv = np.tensordot(U, Q_inv, axes=(1, 0))
        # This works but badly conditioned
        Myav = np.tensordot(M, self.y_stats.get_mean(), axes=(1, 0))
        N = UQ_inv - Myav

        if self.antisym_M:
            self.info('antisymmetrizing M')
            M = antisym(M)
        
#         # Note: this does not work, don't know why
#         if False:
#             printm('MYav1', Myav)
#             y2 = np.linalg.solve(P, self.y_stats.get_mean())
#             Myav2 = np.tensordot(T, y2, axes=(0, 0))
#             # Myav = np.tensordot(T, y2, axes=(1, 0))
#             printm('MYav2', Myav2)
#         if False:
#             printm('U', U, 'Q_inv', Q_inv)
#             printm('UQ_inv', UQ_inv, 'Myav', Myav, 'N', N)
#             printm('u_mean', self.u_stats.get_mean())
#             printm('u_std', np.sqrt(Q.diagonal()))
#             printm('y_mean', self.y_stats.get_mean())
            
        self.Myav = Myav
        self.UQ_inv = UQ_inv
            
        return BDSEmodel(M, N)

    def publish(self, pub):
        if not self.once:
            pub.text('warning', 'not updated yet')
            return
        
        pub.text('nsamples', '%s' % self.nsamples)
        
        pub.text('rcond', '%g' % self.rcond)
        with pub.subsection('model') as sub:
            try:
                model = self.get_model()
                model.publish(sub)
            except BDSEEstimatorInterface.NotReady as e:
                pub.text('not-ready', str(e))

        with pub.subsection('tensors') as sub:
            T = self.get_T()
            U = self.U.get_value()
            P = self.y_stats.get_covariance()
            Q = self.u_stats.get_covariance()
            P_inv = np.linalg.pinv(P)
            P_inv_cond = self.get_P_inv_cond()
            Q_inv = np.linalg.pinv(Q)
    #
    #        TP_inv2 = obtain_TP_inv_from_TP_2(T, P)  
    #        M2 = np.tensordot(TP_inv2, Q_inv, axes=(2, 0))
        
            pub_tensor3_slice2(sub, 'T', T)
            pub_tensor2_comp1(sub, 'U', U)
            pub_tensor2_cov(sub, 'P', P, rcond=self.rcond)
            pub_tensor2_cov(sub, 'P_inv', P_inv)
            pub_tensor2_cov(sub, 'P_inv_cond', P_inv_cond)
            pub_tensor2_cov(sub, 'Q', Q)
            pub_tensor2_cov(sub, 'Q_inv', Q_inv)
            # Might not have been computed
            # pub_tensor2_comp1(sub, 'Myav', self.Myav)
            # pub_tensor2_comp1(sub, 'UQ_inv', self.UQ_inv)

        with pub.subsection('y_stats') as sub:
            self.y_stats.publish(sub)

        with pub.subsection('u_stats') as sub:
            self.u_stats.publish(sub)
          
        with pub.subsection('alternative', robust=True) as sub:
            sub.text('info', 'This is estimating without conditioning P')
            T = self.get_T() 
            P = self.y_stats.get_covariance()
            Q = self.u_stats.get_covariance()
            
            M1 = get_M_from_P_T_Q(P, T, Q)
            pub_tensor3_slice2(sub, 'get_M_from_P_T_Q', M1)
            
            M2 = get_M_from_P_T_Q_alt(P, T, Q)
            pub_tensor3_slice2(sub, 'get_M_from_P_T_Q_alt', M2)

            M3 = get_M_from_P_T_Q_alt_scaling(P, T, Q)
            pub_tensor3_slice2(sub, 'get_M_from_P_T_Q_alt2', M3)