Exemplo n.º 1
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def white_noise_block(vary=False):
    """
    Returns the white noise block of the model:
        1. EFAC per backend/receiver system
        2. EQUAD per backend/receiver system
        3. ECORR per backend/receiver system
    :param vary:
        If set to true we vary these parameters
        with uniform priors. Otherwise they are set to constants
        with values to be set later.
    """

    # define selection by observing backend
    selection = selections.Selection(selections.by_backend)

    # white noise parameters
    if vary:
        efac = parameter.Uniform(0.01, 10.0)
        equad = parameter.Uniform(-8.5, -5)
        ecorr = parameter.Uniform(-8.5, -5)
    else:
        efac = parameter.Constant()
        equad = parameter.Constant()
        ecorr = parameter.Constant()

    # white noise signals
    ef = white_signals.MeasurementNoise(efac=efac, selection=selection)
    eq = white_signals.EquadNoise(log10_equad=equad, selection=selection)
    ec = white_signals.EcorrKernelNoise(log10_ecorr=ecorr, selection=selection)

    # combine signals
    s = ef + eq + ec

    return s
Exemplo n.º 2
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    def test_compare_ecorr_likelihood(self):
        """Compare basis and kernel ecorr methods."""

        selection = Selection(selections.nanograv_backends)
        ef = white_signals.MeasurementNoise()
        ec = white_signals.EcorrKernelNoise(selection=selection)
        ec2 = gp_signals.EcorrBasisModel(selection=selection)
        tm = gp_signals.TimingModel()
        m = ef + ec + tm
        m2 = ef + ec2 + tm

        pta1 = signal_base.PTA([m(p) for p in self.psrs])
        pta2 = signal_base.PTA([m2(p) for p in self.psrs])

        params = parameter.sample(pta1.params)
        l1 = pta1.get_lnlikelihood(params)

        # need to translate some names for EcorrBasis
        basis_params = {}
        for parname, parval in params.items():
            if "log10_ecorr" in parname:
                toks = parname.split("_")
                basisname = toks[0] + "_basis_ecorr_" + "_".join(toks[1:])
                basis_params[basisname] = parval
        params.update(basis_params)
        l2 = pta2.get_lnlikelihood(params)

        msg = "Likelihood mismatch between ECORR methods"
        assert np.allclose(l1, l2), msg
Exemplo n.º 3
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  def ecorr(self,option="by_backend"):
    """
    Similar to EFAC and EQUAD, ECORR is a white noise parameter that
    describes a correlation between ToAs in a single epoch (observation).

    Arzoumanian, Zaven, et al. The Astrophysical Journal 859.1 (2018): 47.
    """
    if option not in selections.__dict__.keys():
      raise ValueError('ECORR option must be Enterprise selection function \
                        name')
    se=selections.Selection(selections.__dict__[option])
    ecorrpr = interpret_white_noise_prior(self.params.ecorr)
    ecs = white_signals.EcorrKernelNoise(log10_ecorr=ecorrpr,selection=se)
    return ecs
Exemplo n.º 4
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log10_A_gw_1 = parameter.Uniform(-18, -13)('zlog10_A_gw')
gamma_gw_1 = parameter.Constant(13 / 3)('zgamma_gw')

# Second GW parameters
log10_A_gw_2 = parameter.Uniform(-18, -13)('zlog10_A_other_gw')
gamma_gw_2 = parameter.Constant(7 / 3)('zgamma_other_gw')

##### Set up signals #####

# timing model
tm = gp_signals.TimingModel()

# white noise
ef = white_signals.MeasurementNoise(efac=efac, selection=selection)
eq = white_signals.EquadNoise(log10_equad=log10_equad, selection=selection)
ec = white_signals.EcorrKernelNoise(log10_ecorr=log10_ecorr,
                                    selection=selection)

# red noise (powerlaw with 30 frequencies)
pl = utils.powerlaw(log10_A=red_noise_log10_A, gamma=red_noise_gamma)
rn = gp_signals.FourierBasisGP(spectrum=pl, components=30, Tspan=Tspan)

cpl_1 = utils.powerlaw(log10_A=log10_A_gw_1, gamma=gamma_gw_1)
cpl_2 = utils.powerlaw(log10_A=log10_A_gw_2, gamma=gamma_gw_2)

#Common red noise process with no correlations
crn_1 = gp_signals.FourierBasisGP(spectrum=cpl_1,
                                  components=30,
                                  Tspan=Tspan,
                                  name='gw')
crn_2 = gp_signals.FourierBasisGP(spectrum=cpl_2,
                                  components=30,
Exemplo n.º 5
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def white_noise_block(vary=False,
                      inc_ecorr=False,
                      gp_ecorr=False,
                      efac1=False,
                      select='backend',
                      name=None):
    """
    Returns the white noise block of the model:

        1. EFAC per backend/receiver system
        2. EQUAD per backend/receiver system
        3. ECORR per backend/receiver system

    :param vary:
        If set to true we vary these parameters
        with uniform priors. Otherwise they are set to constants
        with values to be set later.
    :param inc_ecorr:
        include ECORR, needed for NANOGrav channelized TOAs
    :param gp_ecorr:
        whether to use the Gaussian process model for ECORR
    :param efac1:
        use a strong prior on EFAC = Normal(mu=1, stdev=0.1)
    """

    if select == 'backend':
        # define selection by observing backend
        backend = selections.Selection(selections.by_backend)
        # define selection by nanograv backends
        backend_ng = selections.Selection(selections.nanograv_backends)
    else:
        # define no selection
        backend = selections.Selection(selections.no_selection)

    # white noise parameters
    if vary:
        if efac1:
            efac = parameter.Normal(1.0, 0.1)
        else:
            efac = parameter.Uniform(0.01, 10.0)
        equad = parameter.Uniform(-8.5, -5)
        if inc_ecorr:
            ecorr = parameter.Uniform(-8.5, -5)
    else:
        efac = parameter.Constant()
        equad = parameter.Constant()
        if inc_ecorr:
            ecorr = parameter.Constant()

    # white noise signals
    ef = white_signals.MeasurementNoise(efac=efac,
                                        selection=backend,
                                        name=name)
    eq = white_signals.EquadNoise(log10_equad=equad,
                                  selection=backend,
                                  name=name)
    if inc_ecorr:
        if gp_ecorr:
            if name is None:
                ec = gp_signals.EcorrBasisModel(log10_ecorr=ecorr,
                                                selection=backend_ng)
            else:
                ec = gp_signals.EcorrBasisModel(log10_ecorr=ecorr,
                                                selection=backend_ng,
                                                name=name)

        else:
            ec = white_signals.EcorrKernelNoise(log10_ecorr=ecorr,
                                                selection=backend_ng,
                                                name=name)

    # combine signals
    if inc_ecorr:
        s = ef + eq + ec
    elif not inc_ecorr:
        s = ef + eq

    return s
Exemplo n.º 6
0
    def test_single_pulsar(self):

        # get parameters from PAL2 style noise files
        params = get_noise_from_pal2(datadir + "/B1855+09_noise.txt")

        # setup basic model
        efac = parameter.Constant()
        equad = parameter.Constant()
        ecorr = parameter.Constant()
        log10_A = parameter.Constant()
        gamma = parameter.Constant()

        selection = Selection(selections.by_backend)

        ms = white_signals.MeasurementNoise(efac=efac,
                                            log10_t2equad=equad,
                                            selection=selection)
        ec = white_signals.EcorrKernelNoise(log10_ecorr=ecorr,
                                            selection=selection)

        pl = utils.powerlaw(log10_A=log10_A, gamma=gamma)
        rn = gp_signals.FourierBasisGP(pl)

        s = ms + ec + rn
        m = s(self.psrs[0])

        # set parameters
        m.set_default_params(params)

        # get parameters
        efacs = [params[key] for key in sorted(params.keys()) if "efac" in key]
        equads = [
            params[key] for key in sorted(params.keys()) if "equad" in key
        ]
        ecorrs = [
            params[key] for key in sorted(params.keys()) if "ecorr" in key
        ]
        log10_A = params["B1855+09_red_noise_log10_A"]
        gamma = params["B1855+09_red_noise_gamma"]

        # correct value
        flags = ["430_ASP", "430_PUPPI", "L-wide_ASP", "L-wide_PUPPI"]
        nvec0 = np.zeros_like(self.psrs[0].toas)
        for ct, flag in enumerate(np.unique(flags)):
            ind = flag == self.psrs[0].backend_flags
            nvec0[ind] = efacs[ct]**2 * (
                self.psrs[0].toaerrs[ind]**2 +
                10**(2 * equads[ct]) * np.ones(np.sum(ind)))

        # get the basis
        bflags = self.psrs[0].backend_flags
        Umats = []
        for flag in np.unique(bflags):
            mask = bflags == flag
            Umats.append(
                utils.create_quantization_matrix(self.psrs[0].toas[mask])[0])
        nepoch = sum(U.shape[1] for U in Umats)
        U = np.zeros((len(self.psrs[0].toas), nepoch))
        jvec = np.zeros(nepoch)
        netot = 0
        for ct, flag in enumerate(np.unique(bflags)):
            mask = bflags == flag
            nn = Umats[ct].shape[1]
            U[mask, netot:nn + netot] = Umats[ct]
            jvec[netot:nn + netot] = 10**(2 * ecorrs[ct])
            netot += nn

        # get covariance matrix
        cov = np.diag(nvec0) + np.dot(U * jvec[None, :], U.T)
        cf = sl.cho_factor(cov)
        logdet = np.sum(2 * np.log(np.diag(cf[0])))

        # test
        msg = "EFAC/ECORR logdet incorrect."
        N = m.get_ndiag(params)
        assert np.allclose(N.solve(self.psrs[0].residuals, logdet=True)[1],
                           logdet,
                           rtol=1e-10), msg

        msg = "EFAC/ECORR D1 solve incorrect."
        assert np.allclose(N.solve(self.psrs[0].residuals),
                           sl.cho_solve(cf, self.psrs[0].residuals),
                           rtol=1e-10), msg

        msg = "EFAC/ECORR 1D1 solve incorrect."
        assert np.allclose(
            N.solve(self.psrs[0].residuals, left_array=self.psrs[0].residuals),
            np.dot(self.psrs[0].residuals,
                   sl.cho_solve(cf, self.psrs[0].residuals)),
            rtol=1e-10,
        ), msg

        msg = "EFAC/ECORR 2D1 solve incorrect."
        T = m.get_basis(params)
        assert np.allclose(
            N.solve(self.psrs[0].residuals, left_array=T),
            np.dot(T.T, sl.cho_solve(cf, self.psrs[0].residuals)),
            rtol=1e-10,
        ), msg

        msg = "EFAC/ECORR 2D2 solve incorrect."
        assert np.allclose(N.solve(T, left_array=T),
                           np.dot(T.T, sl.cho_solve(cf, T)),
                           rtol=1e-10), msg

        F, f2 = utils.createfourierdesignmatrix_red(self.psrs[0].toas,
                                                    nmodes=20)

        # spectrum test
        phi = utils.powerlaw(f2, log10_A=log10_A, gamma=gamma)
        msg = "Spectrum incorrect for GP Fourier signal."
        assert np.all(m.get_phi(params) == phi), msg

        # inverse spectrum test
        msg = "Spectrum inverse incorrect for GP Fourier signal."
        assert np.all(m.get_phiinv(params) == 1 / phi), msg
Exemplo n.º 7
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    def test_pta(self):

        # get parameters from PAL2 style noise files
        params = get_noise_from_pal2(datadir + "/B1855+09_noise.txt")
        params2 = get_noise_from_pal2(datadir + "/J1909-3744_noise.txt")
        params.update(params2)

        # setup basic model
        efac = parameter.Constant()
        equad = parameter.Constant()
        ecorr = parameter.Constant()
        log10_A = parameter.Constant()
        gamma = parameter.Constant()

        selection = Selection(selections.by_backend)

        ms = white_signals.MeasurementNoise(efac=efac,
                                            log10_t2equad=equad,
                                            selection=selection)
        ec = white_signals.EcorrKernelNoise(log10_ecorr=ecorr,
                                            selection=selection)

        pl = utils.powerlaw(log10_A=log10_A, gamma=gamma)
        rn = gp_signals.FourierBasisGP(pl)

        s = ms + ec + rn
        pta = s(self.psrs[0]) + s(self.psrs[1])

        # set parameters
        pta.set_default_params(params)

        # get parameters
        efacs, equads, ecorrs, log10_A, gamma = [], [], [], [], []
        for pname in [p.name for p in self.psrs]:
            efacs.append([
                params[key] for key in sorted(params.keys())
                if "efac" in key and pname in key
            ])
            equads.append([
                params[key] for key in sorted(params.keys())
                if "equad" in key and pname in key
            ])
            ecorrs.append([
                params[key] for key in sorted(params.keys())
                if "ecorr" in key and pname in key
            ])
            log10_A.append(params["{}_red_noise_log10_A".format(pname)])
            gamma.append(params["{}_red_noise_gamma".format(pname)])

        # correct value
        tflags = [sorted(list(np.unique(p.backend_flags))) for p in self.psrs]
        cfs, logdets, phis = [], [], []
        for ii, (psr, flags) in enumerate(zip(self.psrs, tflags)):
            nvec0 = np.zeros_like(psr.toas)
            for ct, flag in enumerate(flags):
                ind = psr.backend_flags == flag
                nvec0[ind] = efacs[ii][ct]**2 * (
                    psr.toaerrs[ind]**2 +
                    10**(2 * equads[ii][ct]) * np.ones(np.sum(ind)))

            # get the basis
            bflags = psr.backend_flags
            Umats = []
            for flag in np.unique(bflags):
                mask = bflags == flag
                Umats.append(
                    utils.create_quantization_matrix(psr.toas[mask])[0])
            nepoch = sum(U.shape[1] for U in Umats)
            U = np.zeros((len(psr.toas), nepoch))
            jvec = np.zeros(nepoch)
            netot = 0
            for ct, flag in enumerate(np.unique(bflags)):
                mask = bflags == flag
                nn = Umats[ct].shape[1]
                U[mask, netot:nn + netot] = Umats[ct]
                jvec[netot:nn + netot] = 10**(2 * ecorrs[ii][ct])
                netot += nn

            # get covariance matrix
            cov = np.diag(nvec0) + np.dot(U * jvec[None, :], U.T)
            cf = sl.cho_factor(cov)
            logdet = np.sum(2 * np.log(np.diag(cf[0])))
            cfs.append(cf)
            logdets.append(logdet)

            F, f2 = utils.createfourierdesignmatrix_red(psr.toas, nmodes=20)
            phi = utils.powerlaw(f2, log10_A=log10_A[ii], gamma=gamma[ii])
            phis.append(phi)

        # tests
        Ns = pta.get_ndiag(params)
        pphis = pta.get_phi(params)
        pphiinvs = pta.get_phiinv(params)
        Ts = pta.get_basis(params)
        zipped = zip(logdets, cfs, phis, self.psrs, Ns, pphis, pphiinvs, Ts)
        for logdet, cf, phi, psr, N, pphi, pphiinv, T in zipped:
            msg = "EFAC/ECORR logdet incorrect."
            assert np.allclose(N.solve(psr.residuals, logdet=True)[1],
                               logdet,
                               rtol=1e-10), msg

            msg = "EFAC/ECORR D1 solve incorrect."
            assert np.allclose(N.solve(psr.residuals),
                               sl.cho_solve(cf, psr.residuals),
                               rtol=1e-10), msg

            msg = "EFAC/ECORR 1D1 solve incorrect."
            assert np.allclose(
                N.solve(psr.residuals, left_array=psr.residuals),
                np.dot(psr.residuals, sl.cho_solve(cf, psr.residuals)),
                rtol=1e-10,
            ), msg

            msg = "EFAC/ECORR 2D1 solve incorrect."
            assert np.allclose(N.solve(psr.residuals, left_array=T),
                               np.dot(T.T, sl.cho_solve(cf, psr.residuals)),
                               rtol=1e-10), msg

            msg = "EFAC/ECORR 2D2 solve incorrect."
            assert np.allclose(N.solve(T, left_array=T),
                               np.dot(T.T, sl.cho_solve(cf, T)),
                               rtol=1e-10), msg

            # spectrum test
            msg = "Spectrum incorrect for GP Fourier signal."
            assert np.all(pphi == phi), msg

            # inverse spectrum test
            msg = "Spectrum inverse incorrect for GP Fourier signal."
            assert np.all(pphiinv == 1 / phi), msg
Exemplo n.º 8
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    def _ecorr_test_ipta(self, method="sparse"):
        """Test of sparse/sherman-morrison ecorr signal and solve methods."""
        selection = Selection(selections.nanograv_backends)

        efac = parameter.Uniform(0.1, 5)
        ecorr = parameter.Uniform(-10, -5)
        ef = white_signals.MeasurementNoise(efac=efac)
        ec = white_signals.EcorrKernelNoise(log10_ecorr=ecorr,
                                            selection=selection,
                                            method=method)
        tm = gp_signals.TimingModel()
        s = ef + ec + tm
        m = s(self.ipsr)

        # set parameters
        efacs = [1.3]
        ecorrs = [-6.1, -6.2, -6.3, -6.4, -7.2, -8.4, -7.1, -7.9]
        params = {
            "J1713+0747_efac": efacs[0],
            "J1713+0747_ASP-L_log10_ecorr": ecorrs[0],
            "J1713+0747_ASP-S_log10_ecorr": ecorrs[1],
            "J1713+0747_GASP-8_log10_ecorr": ecorrs[2],
            "J1713+0747_GASP-L_log10_ecorr": ecorrs[3],
            "J1713+0747_GUPPI-8_log10_ecorr": ecorrs[4],
            "J1713+0747_GUPPI-L_log10_ecorr": ecorrs[5],
            "J1713+0747_PUPPI-L_log10_ecorr": ecorrs[6],
            "J1713+0747_PUPPI-S_log10_ecorr": ecorrs[7],
        }

        # get EFAC Nvec
        nvec0 = efacs[0]**2 * self.ipsr.toaerrs**2

        # get the basis
        flags = [
            "ASP-L", "ASP-S", "GASP-8", "GASP-L", "GUPPI-8", "GUPPI-L",
            "PUPPI-L", "PUPPI-S"
        ]
        bflags = self.ipsr.backend_flags
        Umats = []
        for flag in np.unique(bflags):
            if flag in flags:
                mask = bflags == flag
                Umats.append(
                    utils.create_quantization_matrix(self.ipsr.toas[mask],
                                                     nmin=2)[0])
        nepoch = sum(U.shape[1] for U in Umats)
        U = np.zeros((len(self.ipsr.toas), nepoch))
        jvec = np.zeros(nepoch)
        netot, ct = 0, 0
        for flag in np.unique(bflags):
            if flag in flags:
                mask = bflags == flag
                nn = Umats[ct].shape[1]
                U[mask, netot:nn + netot] = Umats[ct]
                jvec[netot:nn + netot] = 10**(2 * ecorrs[ct])
                netot += nn
                ct += 1

        # get covariance matrix
        wd = Woodbury(nvec0, U, jvec)

        # test
        msg = "EFAC/ECORR {} logdet incorrect.".format(method)
        N = m.get_ndiag(params)
        assert np.allclose(N.solve(self.ipsr.residuals, logdet=True)[1],
                           wd.logdet(),
                           rtol=1e-8), msg

        msg = "EFAC/ECORR {} D1 solve incorrect.".format(method)
        assert np.allclose(N.solve(self.ipsr.residuals),
                           wd.solve(self.ipsr.residuals),
                           rtol=1e-8), msg

        msg = "EFAC/ECORR {} 1D1 solve incorrect.".format(method)
        assert np.allclose(
            N.solve(self.ipsr.residuals, left_array=self.ipsr.residuals),
            np.dot(self.ipsr.residuals, wd.solve(self.ipsr.residuals)),
            rtol=1e-8,
        ), msg

        msg = "EFAC/ECORR {} 2D1 solve incorrect.".format(method)
        T = m.get_basis()
        assert np.allclose(N.solve(self.ipsr.residuals, left_array=T),
                           np.dot(T.T, wd.solve(self.ipsr.residuals)),
                           rtol=1e-8), msg

        msg = "EFAC/ECORR {} 2D2 solve incorrect.".format(method)
        assert np.allclose(N.solve(T, left_array=T),
                           np.dot(T.T, wd.solve(T)),
                           rtol=1e-8), msg
Exemplo n.º 9
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    def _ecorr_test(self, method="sparse"):
        """Test of sparse/sherman-morrison ecorr signal and solve methods."""
        selection = Selection(selections.by_backend)

        efac = parameter.Uniform(0.1, 5)
        ecorr = parameter.Uniform(-10, -5)
        ef = white_signals.MeasurementNoise(efac=efac, selection=selection)
        ec = white_signals.EcorrKernelNoise(log10_ecorr=ecorr,
                                            selection=selection,
                                            method=method)
        tm = gp_signals.TimingModel()
        s = ef + ec + tm
        m = s(self.psr)

        # set parameters
        efacs = [1.3, 1.4, 1.5, 1.6]
        ecorrs = [-6.1, -6.2, -6.3, -6.4]
        params = {
            "B1855+09_430_ASP_efac": efacs[0],
            "B1855+09_430_PUPPI_efac": efacs[1],
            "B1855+09_L-wide_ASP_efac": efacs[2],
            "B1855+09_L-wide_PUPPI_efac": efacs[3],
            "B1855+09_430_ASP_log10_ecorr": ecorrs[0],
            "B1855+09_430_PUPPI_log10_ecorr": ecorrs[1],
            "B1855+09_L-wide_ASP_log10_ecorr": ecorrs[2],
            "B1855+09_L-wide_PUPPI_log10_ecorr": ecorrs[3],
        }

        # get EFAC Nvec
        flags = ["430_ASP", "430_PUPPI", "L-wide_ASP", "L-wide_PUPPI"]
        nvec0 = np.zeros_like(self.psr.toas)
        for ct, flag in enumerate(np.unique(flags)):
            ind = flag == self.psr.backend_flags
            nvec0[ind] = efacs[ct]**2 * self.psr.toaerrs[ind]**2

        # get the basis
        bflags = self.psr.backend_flags
        Umats = []
        for flag in np.unique(bflags):
            mask = bflags == flag
            Umats.append(
                utils.create_quantization_matrix(self.psr.toas[mask],
                                                 nmin=2)[0])
        nepoch = sum(U.shape[1] for U in Umats)
        U = np.zeros((len(self.psr.toas), nepoch))
        jvec = np.zeros(nepoch)
        netot = 0
        for ct, flag in enumerate(np.unique(bflags)):
            mask = bflags == flag
            nn = Umats[ct].shape[1]
            U[mask, netot:nn + netot] = Umats[ct]
            jvec[netot:nn + netot] = 10**(2 * ecorrs[ct])
            netot += nn

        # get covariance matrix
        wd = Woodbury(nvec0, U, jvec)

        # test
        msg = "EFAC/ECORR {} logdet incorrect.".format(method)
        N = m.get_ndiag(params)
        assert np.allclose(N.solve(self.psr.residuals, logdet=True)[1],
                           wd.logdet(),
                           rtol=1e-10), msg

        msg = "EFAC/ECORR {} D1 solve incorrect.".format(method)
        assert np.allclose(N.solve(self.psr.residuals),
                           wd.solve(self.psr.residuals),
                           rtol=1e-10), msg

        msg = "EFAC/ECORR {} 1D1 solve incorrect.".format(method)
        assert np.allclose(
            N.solve(self.psr.residuals, left_array=self.psr.residuals),
            np.dot(self.psr.residuals, wd.solve(self.psr.residuals)),
            rtol=1e-10,
        ), msg

        msg = "EFAC/ECORR {} 2D1 solve incorrect.".format(method)
        T = m.get_basis()
        assert np.allclose(N.solve(self.psr.residuals, left_array=T),
                           np.dot(T.T, wd.solve(self.psr.residuals)),
                           rtol=1e-10), msg

        msg = "EFAC/ECORR {} 2D2 solve incorrect.".format(method)
        assert np.allclose(N.solve(T, left_array=T),
                           np.dot(T.T, wd.solve(T)),
                           rtol=1e-10), msg
Exemplo n.º 10
0
    def compute_like(self, npsrs=1, inc_corr=False, inc_kernel=False):

        # get parameters from PAL2 style noise files
        params = get_noise_from_pal2(datadir + "/B1855+09_noise.txt")
        params2 = get_noise_from_pal2(datadir + "/J1909-3744_noise.txt")
        params.update(params2)

        psrs = self.psrs if npsrs == 2 else [self.psrs[0]]

        if inc_corr:
            params.update({"GW_gamma": 4.33, "GW_log10_A": -15.0})

        # find the maximum time span to set GW frequency sampling
        tmin = [p.toas.min() for p in psrs]
        tmax = [p.toas.max() for p in psrs]
        Tspan = np.max(tmax) - np.min(tmin)

        # setup basic model
        efac = parameter.Constant()
        equad = parameter.Constant()
        ecorr = parameter.Constant()
        log10_A = parameter.Constant()
        gamma = parameter.Constant()

        selection = Selection(selections.by_backend)

        ef = white_signals.MeasurementNoise(efac=efac, selection=selection)
        eq = white_signals.EquadNoise(log10_equad=equad, selection=selection)
        ec = white_signals.EcorrKernelNoise(log10_ecorr=ecorr,
                                            selection=selection)

        pl = utils.powerlaw(log10_A=log10_A, gamma=gamma)
        rn = gp_signals.FourierBasisGP(pl)

        orf = utils.hd_orf()
        crn = gp_signals.FourierBasisCommonGP(pl,
                                              orf,
                                              components=20,
                                              name="GW",
                                              Tspan=Tspan)

        tm = gp_signals.TimingModel()

        log10_sigma = parameter.Uniform(-10, -5)
        log10_lam = parameter.Uniform(np.log10(86400), np.log10(1500 * 86400))
        basis = create_quant_matrix(dt=7 * 86400)
        prior = se_kernel(log10_sigma=log10_sigma, log10_lam=log10_lam)
        se = gp_signals.BasisGP(prior, basis, name="se")

        # set up kernel stuff
        if isinstance(inc_kernel, bool):
            inc_kernel = [inc_kernel] * npsrs

        if inc_corr:
            s = ef + eq + ec + rn + crn + tm
        else:
            s = ef + eq + ec + rn + tm

        models = []
        for ik, psr in zip(inc_kernel, psrs):
            snew = s + se if ik else s
            models.append(snew(psr))

        pta = signal_base.PTA(models)

        # set parameters
        pta.set_default_params(params)

        # SE kernel parameters
        log10_sigmas, log10_lams = [-7.0, -6.5], [7.0, 6.5]
        params.update({
            "B1855+09_se_log10_lam": log10_lams[0],
            "B1855+09_se_log10_sigma": log10_sigmas[0],
            "J1909-3744_se_log10_lam": log10_lams[1],
            "J1909-3744_se_log10_sigma": log10_sigmas[1],
        })

        # get parameters
        efacs, equads, ecorrs, log10_A, gamma = [], [], [], [], []
        lsig, llam = [], []
        for pname in [p.name for p in psrs]:
            efacs.append([
                params[key] for key in sorted(params.keys())
                if "efac" in key and pname in key
            ])
            equads.append([
                params[key] for key in sorted(params.keys())
                if "equad" in key and pname in key
            ])
            ecorrs.append([
                params[key] for key in sorted(params.keys())
                if "ecorr" in key and pname in key
            ])
            log10_A.append(params["{}_red_noise_log10_A".format(pname)])
            gamma.append(params["{}_red_noise_gamma".format(pname)])
            lsig.append(params["{}_se_log10_sigma".format(pname)])
            llam.append(params["{}_se_log10_lam".format(pname)])
        GW_gamma = 4.33
        GW_log10_A = -15.0

        # correct value
        tflags = [sorted(list(np.unique(p.backend_flags))) for p in psrs]
        cfs, logdets, phis, Ts = [], [], [], []
        for ii, (ik, psr, flags) in enumerate(zip(inc_kernel, psrs, tflags)):
            nvec0 = np.zeros_like(psr.toas)
            for ct, flag in enumerate(flags):
                ind = psr.backend_flags == flag
                nvec0[ind] = efacs[ii][ct]**2 * psr.toaerrs[ind]**2
                nvec0[ind] += 10**(2 * equads[ii][ct]) * np.ones(np.sum(ind))

            # get the basis
            bflags = psr.backend_flags
            Umats = []
            for flag in np.unique(bflags):
                mask = bflags == flag
                Umats.append(
                    utils.create_quantization_matrix(psr.toas[mask])[0])
            nepoch = sum(U.shape[1] for U in Umats)
            U = np.zeros((len(psr.toas), nepoch))
            jvec = np.zeros(nepoch)
            netot = 0
            for ct, flag in enumerate(np.unique(bflags)):
                mask = bflags == flag
                nn = Umats[ct].shape[1]
                U[mask, netot:nn + netot] = Umats[ct]
                jvec[netot:nn + netot] = 10**(2 * ecorrs[ii][ct])
                netot += nn

            # get covariance matrix
            cov = np.diag(nvec0) + np.dot(U * jvec[None, :], U.T)
            cf = sl.cho_factor(cov)
            logdet = np.sum(2 * np.log(np.diag(cf[0])))
            cfs.append(cf)
            logdets.append(logdet)

            F, f2 = utils.createfourierdesignmatrix_red(psr.toas,
                                                        nmodes=20,
                                                        Tspan=Tspan)
            Mmat = psr.Mmat.copy()
            norm = np.sqrt(np.sum(Mmat**2, axis=0))
            Mmat /= norm
            U2, avetoas = create_quant_matrix(psr.toas, dt=7 * 86400)
            if ik:
                T = np.hstack((F, Mmat, U2))
            else:
                T = np.hstack((F, Mmat))
            Ts.append(T)
            phi = utils.powerlaw(f2, log10_A=log10_A[ii], gamma=gamma[ii])
            if inc_corr:
                phigw = utils.powerlaw(f2, log10_A=GW_log10_A, gamma=GW_gamma)
            else:
                phigw = np.zeros(40)
            K = se_kernel(avetoas,
                          log10_sigma=log10_sigmas[ii],
                          log10_lam=log10_lams[ii])
            k = np.diag(
                np.concatenate((phi + phigw, np.ones(Mmat.shape[1]) * 1e40)))
            if ik:
                k = sl.block_diag(k, K)
            phis.append(k)

        # manually compute loglike
        loglike = 0
        TNrs, TNTs = [], []
        for ct, psr in enumerate(psrs):
            TNrs.append(np.dot(Ts[ct].T, sl.cho_solve(cfs[ct], psr.residuals)))
            TNTs.append(np.dot(Ts[ct].T, sl.cho_solve(cfs[ct], Ts[ct])))
            loglike += -0.5 * (
                np.dot(psr.residuals, sl.cho_solve(cfs[ct], psr.residuals)) +
                logdets[ct])

        TNr = np.concatenate(TNrs)
        phi = sl.block_diag(*phis)

        if inc_corr:
            hd = utils.hd_orf(psrs[0].pos, psrs[1].pos)
            phi[len(phis[0]):len(phis[0]) + 40, :40] = np.diag(phigw * hd)
            phi[:40, len(phis[0]):len(phis[0]) + 40] = np.diag(phigw * hd)

        cf = sl.cho_factor(phi)
        phiinv = sl.cho_solve(cf, np.eye(phi.shape[0]))
        logdetphi = np.sum(2 * np.log(np.diag(cf[0])))
        Sigma = sl.block_diag(*TNTs) + phiinv

        cf = sl.cho_factor(Sigma)
        expval = sl.cho_solve(cf, TNr)
        logdetsigma = np.sum(2 * np.log(np.diag(cf[0])))

        loglike -= 0.5 * (logdetphi + logdetsigma)
        loglike += 0.5 * np.dot(TNr, expval)

        method = ["partition", "sparse", "cliques"]
        for mth in method:
            eloglike = pta.get_lnlikelihood(params, phiinv_method=mth)
            msg = "Incorrect like for npsr={}, phiinv={}".format(npsrs, mth)
            assert np.allclose(eloglike, loglike), msg
Exemplo n.º 11
0
rn_gamma = parameter.Uniform(0, 7)
rn_pl = utils.powerlaw(log10_A=rn_log10_A, gamma=rn_gamma)

# GWB parameters and powerlaw
orf = utils.hd_orf()
if args.ul:
    gwb_log10_A = parameter.LinearExp(-18, -12)('gwb_log10_A')
else:
    gwb_log10_A = parameter.Uniform(-18, -12)('gwb_log10_A')
gwb_gamma = parameter.Constant(13 / 3)('gwb_gamma')
gwb_pl = utils.powerlaw(log10_A=gwb_log10_A, gamma=gwb_gamma)

# signals
ef = white_signals.MeasurementNoise(efac=efac, selection=bkend)
eq = white_signals.EquadNoise(log10_equad=equad, selection=bkend)
ec = white_signals.EcorrKernelNoise(log10_ecorr=ecorr, selection=bkend_NG)

dmgp = gp_signals.BasisGP(dm_pl, dm_basis, name='dm_gp')
dmexp = models.dm_exponential_dip(tmin=54500, tmax=55000, name='dmexp_1')
dm1yr = models.dm_annual_signal()

rn = gp_signals.FourierBasisGP(spectrum=rn_pl, components=30, Tspan=Tspan)
gwb = gp_signals.FourierBasisCommonGP(gwb_pl,
                                      orf,
                                      components=30,
                                      Tspan=Tspan,
                                      name='gw')

tm = gp_signals.TimingModel(use_svd=True)
be = deterministic_signals.PhysicalEphemerisSignal(  # widen prior on jup orbit
    use_epoch_toas=True,