Ejemplo n.º 1
0
    def __init__(self,
                 domain,
                 v_p,
                 wavelet,
                 source_tag,
                 dt=None,
                 p0=None,
                 p0_t=None,
                 absorption_zone=300 * U.m,
                 absorption_cut=1e-2,
                 lumping=True):
        """
           initialize the sonic wave solver

           :param domain: domain of the problem
           :type domain: `Domain`
           :param v_p: p-velocity field
           :type v_p: `escript.Scalar`
           :param wavelet: wavelet to describe the time evolution of source term
           :type wavelet: `Wavelet`
           :param source_tag: tag of the source location
           :type source_tag: 'str' or 'int'
           :param dt: time step size. If not present a suitable time step size is calculated.
           :param p0: initial solution. If not present zero is used.
           :param p0_t: initial solution change rate. If not present zero is used.
           :param absorption_zone: thickness of absorption zone
           :param absorption_cut: boundary value of absorption decay factor
           :param lumping: if True mass matrix lumping is being used. This is accelerates the computing but introduces some diffusion.
           """
        f = createAbsorptionLayerFunction(
            escript.Function(domain).getX(), absorption_zone, absorption_cut)
        v_p = v_p * f

        if p0 == None:
            p0 = escript.Scalar(0., escript.Solution(domain))
        else:
            p0 = escript.interpolate(p0, escript.Solution(domain))

        if p0_t == None:
            p0_t = escript.Scalar(0., escript.Solution(domain))
        else:
            p0_t = escript.interpolate(p0_t, escript.Solution(domain))

        if dt == None:
            dt = min(escript.inf((1. / 5.) * domain.getSize() / v_p),
                     wavelet.getTimeScale())

        super(SonicWave, self).__init__(dt, u0=p0, v0=p0_t, t0=0.)

        self.__wavelet = wavelet
        self.__mypde = lpde.LinearSinglePDE(domain)
        if lumping:
            self.__mypde.getSolverOptions().setSolverMethod(
                lpde.SolverOptions.HRZ_LUMPING)
        self.__mypde.setSymmetryOn()
        self.__mypde.setValue(D=1. / v_p**2)
        self.__source_tag = source_tag
        self.__r = escript.Scalar(
            0., escript.DiracDeltaFunctions(self.__mypde.getDomain()))
Ejemplo n.º 2
0
 def createLevelSetFunction(self, *props):
     """
     returns an instance of an object used to represent a level set function
     initialized with zeros. Components can be overwritten by physical
     properties `props`. If present entries must correspond to the
     `mappings` arguments in the constructor. Use ``None`` for properties
     for which no value is given.
     """
     m=self.regularization.getPDE().createSolution()
     if len(props) > 0:
         for i in range(self.numMappings):
             if props[i]:
                 mp, idx=self.mappings[i]
                 m2=mp.getInverse(props[i])
                 if idx:
                     if len(idx) == 1:
                         m[idx[0]]=m2
                     else:
                         for k in range(idx): m[idx[k]]=m2[k]
                 else:
                     if isinstance(m2, Data):
                        m=interpolate(m2, m.getFunctionSpace())
                     else:
                        m=Data(m2, m.getFunctionSpace())
     return m
 def createLevelSetFunction(self, *props):
     """
     returns an instance of an object used to represent a level set function
     initialized with zeros. Components can be overwritten by physical
     properties `props`. If present entries must correspond to the
     `mappings` arguments in the constructor. Use ``None`` for properties
     for which no value is given.
     """
     m=self.regularization.getPDE().createSolution()
     if len(props) > 0:
         for i in range(self.numMappings):
             if props[i]:
                 mp, idx=self.mappings[i]
                 m2=mp.getInverse(props[i])
                 if idx:
                     if len(idx) == 1:
                         m[idx[0]]=m2
                     else:
                         for k in range(idx): m[idx[k]]=m2[k]
                 else:
                     if isinstance(m2, Data):
                        m=interpolate(m2, m.getFunctionSpace())
                     else:
                        m=Data(m2, m.getFunctionSpace())
     return m
    def getDefect(self, rho, Hx, g_Hx):
        """
        Returns the defect value.

        :param rho: a suggestion for resistivity
        :type rho: ``Data`` of shape ()
        :param Hx: magnetic field
        :type Hx: ``Data`` of shape (2,)
        :param g_Hx: gradient of magnetic field
        :type g_Hx: ``Data`` of shape (2,2)

        :rtype: ``float``
        """
        x = g_Hx.getFunctionSpace().getX()
        Hx = escript.interpolate(Hx, x.getFunctionSpace())
        u0 = Hx[0]
        u1 = Hx[1]
        u01 = g_Hx[0, 1]
        u11 = g_Hx[1, 1]
        scale = rho / (u0**2 + u1**2)

        Z = self._Z
        A = escript.integrate(
            self._weight * (Z[0]**2 + Z[1]**2 + scale *
                            (-2 * Z[0] * (u0 * u01 + u1 * u11) + 2 * Z[1] *
                             (u1 * u01 - u0 * u11) + rho * (u01**2 + u11**2))))
        return A / 2
    def getDefect(self, sigma, Ex, dExdz):
        """
        Returns the defect value.

        :param sigma: a suggestion for conductivity
        :type sigma: ``Data`` of shape ()
        :param Ex: electric field
        :type Ex: ``Data`` of shape (2,)
        :param dExdz: vertical derivative of electric field
        :type dExdz: ``Data`` of shape (2,)

        :rtype: ``float``
        """
        x = dExdz.getFunctionSpace().getX()
        Ex = escript.interpolate(Ex, x.getFunctionSpace())
        u0 = Ex[0]
        u1 = Ex[1]
        u01 = dExdz[0]
        u11 = dExdz[1]
        scale = self._weight / (u01**2 + u11**2)

        Z = self._Z
        A = escript.integrate(
            scale * ((Z[0]**2 + Z[1]**2) * (u01**2 + u11**2) + 2 * Z[1] *
                     (u0 * u11 - u01 * u1) - 2 * Z[0] *
                     (u0 * u01 + u11 * u1) + u0**2 + u1**2))

        return A / 2
    def getGradient(self, sigma, Ex, dExdz):
        """
        Returns the gradient of the defect with respect to density.

        :param sigma: a suggestion for conductivity
        :type sigma: ``Data`` of shape ()
        :param Ex: electric field
        :type Ex: ``Data`` of shape (2,)
        :param dExdz: vertical derivative of electric field
        :type dExdz: ``Data`` of shape (2,)
        """
        pde = self.setUpPDE()
        DIM = self.getDomain().getDim()

        x = dExdz.getFunctionSpace().getX()
        Ex = escript.interpolate(Ex, x.getFunctionSpace())
        u0 = Ex[0]
        u1 = Ex[1]
        u01 = dExdz[0]
        u11 = dExdz[1]

        D = pde.getCoefficient('D')
        Y = pde.getCoefficient('Y')
        X = pde.getCoefficient('X')
        A = pde.getCoefficient('A')

        A[0, :, 0, :] = escript.kronecker(DIM)
        A[1, :, 1, :] = escript.kronecker(DIM)

        f = self._omega_mu * sigma
        D[0, 1] = f
        D[1, 0] = -f

        Z = self._Z
        scale = 1. / (u01**2 + u11**2)
        scale2 = scale**2
        scale *= self._weight
        scale2 *= self._weight

        Y[0] = scale * (u0 - u01 * Z[0] + u11 * Z[1])
        Y[1] = scale * (u1 - u01 * Z[1] - u11 * Z[0])
        X[0,1] = scale2 * (2*u01*u11*(Z[0]*u1-Z[1]*u0) \
                + (Z[0]*u0+Z[1]*u1)*(u01**2-u11**2)
                - u01*(u0**2 + u1**2))
        X[1,1] = scale2 * (2*u01*u11*(Z[1]*u1+Z[0]*u0) \
                + (Z[1]*u0-Z[0]*u1)*(u01**2-u11**2)
                - u11*(u0**2 + u1**2))

        pde.setValue(A=A, D=D, X=X, Y=Y)
        Zstar = pde.getSolution()
        return (-self._omega_mu) * (Zstar[1] * u0 - Zstar[0] * u1)
Ejemplo n.º 7
0
    def getGradient(self, sigma, u, uTar, uTai, uTu):
        """
        Returns the gradient of the defect with respect to density.

        :param sigma: a suggestion for complex 1/V**2
        :type sigma: ``escript.Data`` of shape (2,)
        :param u: a u vector
        :type u: ``escript.Data`` of shape (2,)
        :param uTar: equals `integrate( w  * (data[0]*u[0]+data[1]*u[1]))`
        :type uTar: `float`
        :param uTai: equals `integrate( w  * (data[1]*u[0]-data[0]*u[1]))`
        :type uTa: `float`
        :param uTu: equals `integrate( w  * (u,u))`
        :type uTu: `float`
        """
        pde = self.setUpPDE()

        if self.scaleF and abs(uTu) > 0:
            Z = ((uTar**2 + uTai**2) / uTu**2) * escript.interpolate(
                u, self.__data.getFunctionSpace())
            Z[0] += (-uTar / uTu) * self.__data[0] + (-uTai /
                                                      uTu) * self.__data[1]
            Z[1] += (-uTar /
                     uTu) * self.__data[1] + uTai / uTu * self.__data[0]

        else:
            Z = u - self.__data
        if Z.getFunctionSpace() == escript.DiracDeltaFunctions(
                self.getDomain()):
            pde.setValue(y_dirac=self.__weight * Z)
        else:
            pde.setValue(y=self.__weight * Z)
        D = pde.getCoefficient('D')
        D[0, 0] = -self.__omega**2 * sigma[0]
        D[0, 1] = -self.__omega**2 * sigma[1]
        D[1, 0] = self.__omega**2 * sigma[1]
        D[1, 1] = -self.__omega**2 * sigma[0]
        pde.setValue(D=D)
        ZTo2 = pde.getSolution() * self.__omega**2
        return escript.inner(
            ZTo2, u) * [1, 0] + (ZTo2[1] * u[0] - ZTo2[0] * u[1]) * [0, 1]
Ejemplo n.º 8
0
    def __init__(self,
                 domain,
                 numLevelSets=1,
                 w0=None,
                 w1=None,
                 wc=None,
                 location_of_set_m=escript.Data(),
                 useDiagonalHessianApproximation=False,
                 tol=1e-8,
                 coordinates=None,
                 scale=None,
                 scale_c=None):
        """
        initialization.

        :param domain: domain
        :type domain: `Domain`
        :param numLevelSets: number of level sets
        :type numLevelSets: ``int``
        :param w0: weighting factor for the m**2 term. If not set zero is assumed.
        :type w0: ``Scalar`` if ``numLevelSets`` == 1 or `Data` object of shape
                  (``numLevelSets`` ,) if ``numLevelSets`` > 1
        :param w1: weighting factor for the grad(m_i) terms. If not set zero is assumed
        :type w1: ``Vector`` if ``numLevelSets`` == 1 or `Data` object of shape
                  (``numLevelSets`` , DIM) if ``numLevelSets`` > 1
        :param wc: weighting factor for the cross gradient terms. If not set
                   zero is assumed. Used for the case if ``numLevelSets`` > 1
                   only. Only values ``wc[l,k]`` in the lower triangle (l<k)
                   are used.
        :type wc: `Data` object of shape (``numLevelSets`` , ``numLevelSets``)
        :param location_of_set_m: marks location of zero values of the level
                                  set function ``m`` by a positive entry.
        :type location_of_set_m: ``Scalar`` if ``numLevelSets`` == 1 or `Data`
                object of shape (``numLevelSets`` ,) if ``numLevelSets`` > 1
        :param useDiagonalHessianApproximation: if True cross gradient terms
                    between level set components are ignored when calculating
                    approximations of the inverse of the Hessian Operator.
                    This can speed-up the calculation of the inverse but may
                    lead to an increase of the number of iteration steps in the
                    inversion.
        :type useDiagonalHessianApproximation: ``bool``
        :param tol: tolerance when solving the PDE for the inverse of the
                    Hessian Operator
        :type tol: positive ``float``

        :param coordinates: defines coordinate system to be used
        :type coordinates: ReferenceSystem` or `SpatialCoordinateTransformation`
        :param scale: weighting factor for level set function variation terms.
                      If not set one is used.
        :type scale: ``Scalar`` if ``numLevelSets`` == 1 or `Data` object of
                     shape (``numLevelSets`` ,) if ``numLevelSets`` > 1
        :param scale_c: scale for the cross gradient terms. If not set
                   one is assumed. Used for the case if ``numLevelSets`` > 1
                   only. Only values ``scale_c[l,k]`` in the lower triangle
                   (l<k) are used.
        :type scale_c: `Data` object of shape (``numLevelSets``,``numLevelSets``)

        """
        if w0 is None and w1 is None:
            raise ValueError("Values for w0 or for w1 must be given.")
        if wc is None and numLevelSets > 1:
            raise ValueError("Values for wc must be given.")

        self.__pre_input = None
        self.__pre_args = None
        self.logger = logging.getLogger('inv.%s' % self.__class__.__name__)
        self.__domain = domain
        DIM = self.__domain.getDim()
        self.__numLevelSets = numLevelSets
        self.__trafo = makeTransformation(domain, coordinates)
        self.__pde = linearPDEs.LinearPDE(self.__domain,
                                          numEquations=self.__numLevelSets,
                                          numSolutions=self.__numLevelSets)
        self.__pde.getSolverOptions().setTolerance(tol)
        self.__pde.setSymmetryOn()
        self.__pde.setValue(
            A=self.__pde.createCoefficient('A'),
            D=self.__pde.createCoefficient('D'),
        )
        try:
            self.__pde.setValue(q=location_of_set_m)
        except linearPDEs.IllegalCoefficientValue:
            raise ValueError(
                "Unable to set location of fixed level set function.")

        # =========== check the shape of the scales: ========================
        if scale is None:
            if numLevelSets == 1:
                scale = 1.
            else:
                scale = np.ones((numLevelSets, ))
        else:
            scale = np.asarray(scale)
            if numLevelSets == 1:
                if scale.shape == ():
                    if not scale > 0:
                        raise ValueError("Value for scale must be positive.")
                else:
                    raise ValueError("Unexpected shape %s for scale." %
                                     scale.shape)
            else:
                if scale.shape is (numLevelSets, ):
                    if not min(scale) > 0:
                        raise ValueError(
                            "All values for scale must be positive.")
                else:
                    raise ValueError("Unexpected shape %s for scale." %
                                     scale.shape)

        if scale_c is None or numLevelSets < 2:
            scale_c = np.ones((numLevelSets, numLevelSets))
        else:
            scale_c = np.asarray(scale_c)
            if scale_c.shape == (numLevelSets, numLevelSets):
                if not all([[scale_c[l, k] > 0. for l in range(k)]
                            for k in range(1, numLevelSets)]):
                    raise ValueError(
                        "All values in the lower triangle of scale_c must be positive."
                    )
            else:
                raise ValueError("Unexpected shape %s for scale." %
                                 scale_c.shape)
        # ===== check the shape of the weights: =============================
        if w0 is not None:
            w0 = escript.interpolate(
                w0, self.__pde.getFunctionSpaceForCoefficient('D'))
            s0 = w0.getShape()
            if numLevelSets == 1:
                if not s0 == ():
                    raise ValueError("Unexpected shape %s for weight w0." %
                                     (s0, ))
            else:
                if not s0 == (numLevelSets, ):
                    raise ValueError("Unexpected shape %s for weight w0." %
                                     (s0, ))
            if not self.__trafo.isCartesian():
                w0 *= self.__trafo.getVolumeFactor()
        if not w1 is None:
            w1 = escript.interpolate(
                w1, self.__pde.getFunctionSpaceForCoefficient('A'))
            s1 = w1.getShape()
            if numLevelSets == 1:
                if not s1 == (DIM, ):
                    raise ValueError("Unexpected shape %s for weight w1." %
                                     (s1, ))
            else:
                if not s1 == (numLevelSets, DIM):
                    raise ValueError("Unexpected shape %s for weight w1." %
                                     (s1, ))
            if not self.__trafo.isCartesian():
                f = self.__trafo.getScalingFactors(
                )**2 * self.__trafo.getVolumeFactor()
                if numLevelSets == 1:
                    w1 *= f
                else:
                    for i in range(numLevelSets):
                        w1[i, :] *= f

        if numLevelSets == 1:
            wc = None
        else:
            wc = escript.interpolate(
                wc, self.__pde.getFunctionSpaceForCoefficient('A'))
            sc = wc.getShape()
            if not sc == (numLevelSets, numLevelSets):
                raise ValueError("Unexpected shape %s for weight wc." % (sc, ))
            if not self.__trafo.isCartesian():
                raise ValueError(
                    "Non-cartesian coordinates for cross-gradient term is not supported yet."
                )
        # ============= now we rescale weights: =============================
        L2s = np.asarray(escript.boundingBoxEdgeLengths(domain))**2
        L4 = 1 / np.sum(1 / L2s)**2
        if numLevelSets == 1:
            A = 0
            if w0 is not None:
                A = escript.integrate(w0)
            if w1 is not None:
                A += escript.integrate(inner(w1, 1 / L2s))
            if A > 0:
                f = scale / A
                if w0 is not None:
                    w0 *= f
                if w1 is not None:
                    w1 *= f
            else:
                raise ValueError("Non-positive weighting factor detected.")
        else:  # numLevelSets > 1
            for k in range(numLevelSets):
                A = 0
                if w0 is not None:
                    A = escript.integrate(w0[k])
                if w1 is not None:
                    A += escript.integrate(inner(w1[k, :], 1 / L2s))
                if A > 0:
                    f = scale[k] / A
                    if w0 is not None:
                        w0[k] *= f
                    if w1 is not None:
                        w1[k, :] *= f
                else:
                    raise ValueError(
                        "Non-positive weighting factor for level set component %d detected."
                        % k)

                # and now the cross-gradient:
                if wc is not None:
                    for l in range(k):
                        A = escript.integrate(wc[l, k]) / L4
                        if A > 0:
                            f = scale_c[l, k] / A
                            wc[l, k] *= f
#                       else:
#                           raise ValueError("Non-positive weighting factor for cross-gradient level set components %d and %d detected."%(l,k))

        self.__w0 = w0
        self.__w1 = w1
        self.__wc = wc

        self.__pde_is_set = False
        if self.__numLevelSets > 1:
            self.__useDiagonalHessianApproximation = useDiagonalHessianApproximation
        else:
            self.__useDiagonalHessianApproximation = True
        self._update_Hessian = True

        self.__num_tradeoff_factors = numLevelSets + (
            (numLevelSets - 1) * numLevelSets) // 2
        self.setTradeOffFactors()
        self.__vol_d = escript.vol(self.__domain)
Ejemplo n.º 9
0
    def __init__(
        self,
        domain,
        numLevelSets=1,
        w0=None,
        w1=None,
        wc=None,
        location_of_set_m=Data(),
        useDiagonalHessianApproximation=False,
        tol=1e-8,
        coordinates=None,
        scale=None,
        scale_c=None,
    ):
        """
        initialization.

        :param domain: domain
        :type domain: `Domain`
        :param numLevelSets: number of level sets
        :type numLevelSets: ``int``
        :param w0: weighting factor for the m**2 term. If not set zero is assumed.
        :type w0: ``Scalar`` if ``numLevelSets`` == 1 or `Data` object of shape
                  (``numLevelSets`` ,) if ``numLevelSets`` > 1
        :param w1: weighting factor for the grad(m_i) terms. If not set zero is assumed
        :type w1: ``Vector`` if ``numLevelSets`` == 1 or `Data` object of shape
                  (``numLevelSets`` , DIM) if ``numLevelSets`` > 1
        :param wc: weighting factor for the cross gradient terms. If not set
                   zero is assumed. Used for the case if ``numLevelSets`` > 1
                   only. Only values ``wc[l,k]`` in the lower triangle (l<k)
                   are used.
        :type wc: `Data` object of shape (``numLevelSets`` , ``numLevelSets``)
        :param location_of_set_m: marks location of zero values of the level
                                  set function ``m`` by a positive entry.
        :type location_of_set_m: ``Scalar`` if ``numLevelSets`` == 1 or `Data`
                object of shape (``numLevelSets`` ,) if ``numLevelSets`` > 1
        :param useDiagonalHessianApproximation: if True cross gradient terms
                    between level set components are ignored when calculating
                    approximations of the inverse of the Hessian Operator.
                    This can speed-up the calculation of the inverse but may
                    lead to an increase of the number of iteration steps in the
                    inversion.
        :type useDiagonalHessianApproximation: ``bool``
        :param tol: tolerance when solving the PDE for the inverse of the
                    Hessian Operator
        :type tol: positive ``float``

        :param coordinates: defines coordinate system to be used
        :type coordinates: ReferenceSystem` or `SpatialCoordinateTransformation`
        :param scale: weighting factor for level set function variation terms.
                      If not set one is used.
        :type scale: ``Scalar`` if ``numLevelSets`` == 1 or `Data` object of
                     shape (``numLevelSets`` ,) if ``numLevelSets`` > 1
        :param scale_c: scale for the cross gradient terms. If not set
                   one is assumed. Used for the case if ``numLevelSets`` > 1
                   only. Only values ``scale_c[l,k]`` in the lower triangle
                   (l<k) are used.
        :type scale_c: `Data` object of shape (``numLevelSets``,``numLevelSets``)

        """
        if w0 is None and w1 is None:
            raise ValueError("Values for w0 or for w1 must be given.")
        if wc is None and numLevelSets > 1:
            raise ValueError("Values for wc must be given.")

        self.__pre_input = None
        self.__pre_args = None
        self.logger = logging.getLogger("inv.%s" % self.__class__.__name__)
        self.__domain = domain
        DIM = self.__domain.getDim()
        self.__numLevelSets = numLevelSets
        self.__trafo = makeTransformation(domain, coordinates)
        self.__pde = LinearPDE(self.__domain, numEquations=self.__numLevelSets, numSolutions=self.__numLevelSets)
        self.__pde.getSolverOptions().setTolerance(tol)
        self.__pde.setSymmetryOn()
        self.__pde.setValue(A=self.__pde.createCoefficient("A"), D=self.__pde.createCoefficient("D"))
        try:
            self.__pde.setValue(q=location_of_set_m)
        except IllegalCoefficientValue:
            raise ValueError("Unable to set location of fixed level set function.")

        # =========== check the shape of the scales: ========================
        if scale is None:
            if numLevelSets == 1:
                scale = 1.0
            else:
                scale = np.ones((numLevelSets,))
        else:
            scale = np.asarray(scale)
            if numLevelSets == 1:
                if scale.shape == ():
                    if not scale > 0:
                        raise ValueError("Value for scale must be positive.")
                else:
                    raise ValueError("Unexpected shape %s for scale." % scale.shape)
            else:
                if scale.shape is (numLevelSets,):
                    if not min(scale) > 0:
                        raise ValueError("All values for scale must be positive.")
                else:
                    raise ValueError("Unexpected shape %s for scale." % scale.shape)

        if scale_c is None or numLevelSets < 2:
            scale_c = np.ones((numLevelSets, numLevelSets))
        else:
            scale_c = np.asarray(scale_c)
            if scale_c.shape == (numLevelSets, numLevelSets):
                if not all([[scale_c[l, k] > 0.0 for l in range(k)] for k in range(1, numLevelSets)]):
                    raise ValueError("All values in the lower triangle of scale_c must be positive.")
            else:
                raise ValueError("Unexpected shape %s for scale." % scale_c.shape)
        # ===== check the shape of the weights: =============================
        if w0 is not None:
            w0 = interpolate(w0, self.__pde.getFunctionSpaceForCoefficient("D"))
            s0 = w0.getShape()
            if numLevelSets == 1:
                if not s0 == ():
                    raise ValueError("Unexpected shape %s for weight w0." % (s0,))
            else:
                if not s0 == (numLevelSets,):
                    raise ValueError("Unexpected shape %s for weight w0." % (s0,))
            if not self.__trafo.isCartesian():
                w0 *= self.__trafo.getVolumeFactor()
        if not w1 is None:
            w1 = interpolate(w1, self.__pde.getFunctionSpaceForCoefficient("A"))
            s1 = w1.getShape()
            if numLevelSets == 1:
                if not s1 == (DIM,):
                    raise ValueError("Unexpected shape %s for weight w1." % (s1,))
            else:
                if not s1 == (numLevelSets, DIM):
                    raise ValueError("Unexpected shape %s for weight w1." % (s1,))
            if not self.__trafo.isCartesian():
                f = self.__trafo.getScalingFactors() ** 2 * self.__trafo.getVolumeFactor()
                if numLevelSets == 1:
                    w1 *= f
                else:
                    for i in range(numLevelSets):
                        w1[i, :] *= f

        if numLevelSets == 1:
            wc = None
        else:
            wc = interpolate(wc, self.__pde.getFunctionSpaceForCoefficient("A"))
            sc = wc.getShape()
            if not sc == (numLevelSets, numLevelSets):
                raise ValueError("Unexpected shape %s for weight wc." % (sc,))
            if not self.__trafo.isCartesian():
                raise ValueError("Non-cartesian coordinates for cross-gradient term is not supported yet.")
        # ============= now we rescale weights: =============================
        L2s = np.asarray(boundingBoxEdgeLengths(domain)) ** 2
        L4 = 1 / np.sum(1 / L2s) ** 2
        if numLevelSets == 1:
            A = 0
            if w0 is not None:
                A = integrate(w0)
            if w1 is not None:
                A += integrate(inner(w1, 1 / L2s))
            if A > 0:
                f = scale / A
                if w0 is not None:
                    w0 *= f
                if w1 is not None:
                    w1 *= f
            else:
                raise ValueError("Non-positive weighting factor detected.")
        else:  # numLevelSets > 1
            for k in range(numLevelSets):
                A = 0
                if w0 is not None:
                    A = integrate(w0[k])
                if w1 is not None:
                    A += integrate(inner(w1[k, :], 1 / L2s))
                if A > 0:
                    f = scale[k] / A
                    if w0 is not None:
                        w0[k] *= f
                    if w1 is not None:
                        w1[k, :] *= f
                else:
                    raise ValueError("Non-positive weighting factor for level set component %d detected." % k)

                # and now the cross-gradient:
                if wc is not None:
                    for l in range(k):
                        A = integrate(wc[l, k]) / L4
                        if A > 0:
                            f = scale_c[l, k] / A
                            wc[l, k] *= f
        #                       else:
        #                           raise ValueError("Non-positive weighting factor for cross-gradient level set components %d and %d detected."%(l,k))

        self.__w0 = w0
        self.__w1 = w1
        self.__wc = wc

        self.__pde_is_set = False
        if self.__numLevelSets > 1:
            self.__useDiagonalHessianApproximation = useDiagonalHessianApproximation
        else:
            self.__useDiagonalHessianApproximation = True
        self._update_Hessian = True

        self.__num_tradeoff_factors = numLevelSets + ((numLevelSets - 1) * numLevelSets) // 2
        self.setTradeOffFactors()
        self.__vol_d = vol(self.__domain)
Ejemplo n.º 10
0
    def __init__(self,
                 domain,
                 v_p,
                 wavelet,
                 source_tag,
                 source_vector=[1., 0.],
                 eps=0.,
                 delta=0.,
                 azimuth=0.,
                 dt=None,
                 p0=None,
                 v0=None,
                 absorption_zone=300 * U.m,
                 absorption_cut=1e-2,
                 lumping=True):
        """
           initialize the HTI wave solver

           :param domain: domain of the problem
           :type domain: `Doamin`
           :param v_p: vertical p-velocity field
           :type v_p: `escript.Scalar`
           :param v_s: vertical s-velocity field
           :type v_s: `escript.Scalar`
           :param wavelet: wavelet to describe the time evolution of source term
           :type wavelet: `Wavelet`
           :param source_tag: tag of the source location
           :type source_tag: 'str' or 'int'
           :param source_vector: source orientation vector
           :param eps: first Thompsen parameter
           :param azimuth: azimuth (rotation around verticle axis)
           :param gamma: third Thompsen parameter
           :param rho: density
           :param dt: time step size. If not present a suitable time step size is calculated.
           :param p0: initial solution (Q(t=0), P(t=0)). If not present zero is used.
           :param v0: initial solution change rate. If not present zero is used.
           :param absorption_zone: thickness of absorption zone
           :param absorption_cut: boundary value of absorption decay factor
           :param lumping: if True mass matrix lumping is being used. This is accelerates the computing but introduces some diffusion.
           """
        DIM = domain.getDim()
        f = createAbsorptionLayerFunction(v_p.getFunctionSpace().getX(),
                                          absorption_zone, absorption_cut)

        self.v2_p = v_p**2
        self.v2_t = self.v2_p * escript.sqrt(1 + 2 * delta)
        self.v2_n = self.v2_p * (1 + 2 * eps)

        if p0 == None:
            p0 = escript.Data(0., (2, ), escript.Solution(domain))
        else:
            p0 = escript.interpolate(p0, escript.Solution(domain))

        if v0 == None:
            v0 = escript.Data(0., (2, ), escript.Solution(domain))
        else:
            v0 = escript.interpolate(v0, escript.Solution(domain))

        if dt == None:
            dt = min(
                min(escript.inf(domain.getSize() / escript.sqrt(self.v2_p)),
                    escript.inf(domain.getSize() / escript.sqrt(self.v2_t)),
                    escript.inf(domain.getSize() / escript.sqrt(self.v2_n))),
                wavelet.getTimeScale()) * 0.2

        super(SonicHTIWave, self).__init__(dt, u0=p0, v0=v0, t0=0.)

        self.__wavelet = wavelet

        self.__mypde = lpde.LinearPDESystem(domain)
        if lumping:
            self.__mypde.getSolverOptions().setSolverMethod(
                lpde.SolverOptions.HRZ_LUMPING)
        self.__mypde.setSymmetryOn()
        self.__mypde.setValue(D=escript.kronecker(2),
                              X=self.__mypde.createCoefficient('X'))
        self.__source_tag = source_tag

        self.__r = escript.Vector(
            0, escript.DiracDeltaFunctions(self.__mypde.getDomain()))
        self.__r.setTaggedValue(self.__source_tag, source_vector)
Ejemplo n.º 11
0
    def __init__(self,
                 domain,
                 v_p,
                 v_s,
                 wavelet,
                 source_tag,
                 source_vector=[0., 1.],
                 eps=0.,
                 delta=0.,
                 theta=0.,
                 rho=1.,
                 dt=None,
                 u0=None,
                 v0=None,
                 absorption_zone=300 * U.m,
                 absorption_cut=1e-2,
                 lumping=True):
        """
           initialize the TTI wave solver

           :param domain: domain of the problem
           :type domain: `Domain`
           :param v_p: vertical p-velocity field
           :type v_p: `escript.Scalar`
           :param v_s: vertical s-velocity field
           :type v_s: `escript.Scalar`
           :param wavelet: wavelet to describe the time evolution of source term
           :type wavelet: `Wavelet`
           :param source_tag: tag of the source location
           :type source_tag: 'str' or 'int'
           :param source_vector: source orientation vector
           :param eps: first Thompsen parameter
           :param delta: second Thompsen parameter
           :param theta: tilting (in Rad)
           :param rho: density
           :param dt: time step size. If not present a suitable time step size is calculated.
           :param u0: initial solution. If not present zero is used.
           :param v0: initial solution change rate. If not present zero is used.
           :param absorption_zone: thickness of absorption zone
           :param absorption_cut: boundary value of absorption decay factor
           :param lumping: if True mass matrix lumping is being used. This is accelerates the computing but introduces some diffusion.
           """
        cos = escript.cos
        sin = escript.sin
        DIM = domain.getDim()
        if not DIM == 2:
            raise ValueError("Only 2D is supported.")
        f = createAbsorptionLayerFunction(
            escript.Function(domain).getX(), absorption_zone, absorption_cut)

        v_p = v_p * f
        v_s = v_s * f

        if u0 == None:
            u0 = escript.Vector(0., escript.Solution(domain))
        else:
            u0 = escript.interpolate(p0, escript.Solution(domain))

        if v0 == None:
            v0 = escript.Vector(0., escript.Solution(domain))
        else:
            v0 = escript.interpolate(v0, escript.Solution(domain))

        if dt == None:
            dt = min((1. / 5.) * min(escript.inf(domain.getSize() / v_p),
                                     escript.inf(domain.getSize() / v_s)),
                     wavelet.getTimeScale())

        super(TTIWave, self).__init__(dt, u0=u0, v0=v0, t0=0.)

        self.__wavelet = wavelet

        self.__mypde = lpde.LinearPDESystem(domain)
        if lumping:
            self.__mypde.getSolverOptions().setSolverMethod(
                lpde.SolverOptions.HRZ_LUMPING)
        self.__mypde.setSymmetryOn()
        self.__mypde.setValue(D=rho * escript.kronecker(DIM),
                              X=self.__mypde.createCoefficient('X'))
        self.__source_tag = source_tag

        self.__r = escript.Vector(
            0, escript.DiracDeltaFunctions(self.__mypde.getDomain()))
        self.__r.setTaggedValue(self.__source_tag, source_vector)

        c0_33 = v_p**2 * rho
        c0_66 = v_s**2 * rho
        c0_11 = (1 + 2 * eps) * c0_33
        c0_13 = escript.sqrt(2 * c0_33 * (c0_33 - c0_66) * delta +
                             (c0_33 - c0_66)**2) - c0_66

        self.c11 = c0_11 * cos(theta)**4 - 2 * c0_13 * cos(
            theta)**4 + 2 * c0_13 * cos(theta)**2 + c0_33 * sin(
                theta)**4 - 4 * c0_66 * cos(theta)**4 + 4 * c0_66 * cos(
                    theta)**2
        self.c13 = -c0_11 * cos(theta)**4 + c0_11 * cos(
            theta)**2 + c0_13 * sin(theta)**4 + c0_13 * cos(
                theta)**4 - c0_33 * cos(theta)**4 + c0_33 * cos(
                    theta)**2 + 4 * c0_66 * cos(theta)**4 - 4 * c0_66 * cos(
                        theta)**2
        self.c16 = (-2 * c0_11 * cos(theta)**2 - 4 * c0_13 * sin(theta)**2 +
                    2 * c0_13 + 2 * c0_33 * sin(theta)**2 - 8 * c0_66 *
                    sin(theta)**2 + 4 * c0_66) * sin(theta) * cos(theta) / 2
        self.c33 = c0_11 * sin(theta)**4 - 2 * c0_13 * cos(
            theta)**4 + 2 * c0_13 * cos(theta)**2 + c0_33 * cos(
                theta)**4 - 4 * c0_66 * cos(theta)**4 + 4 * c0_66 * cos(
                    theta)**2
        self.c36 = (2 * c0_11 * cos(theta)**2 - 2 * c0_11 +
                    4 * c0_13 * sin(theta)**2 - 2 * c0_13 +
                    2 * c0_33 * cos(theta)**2 + 8 * c0_66 * sin(theta)**2 -
                    4 * c0_66) * sin(theta) * cos(theta) / 2
        self.c66 = -c0_11 * cos(theta)**4 + c0_11 * cos(
            theta)**2 + 2 * c0_13 * cos(theta)**4 - 2 * c0_13 * cos(
                theta)**2 - c0_33 * cos(theta)**4 + c0_33 * cos(
                    theta)**2 + c0_66 * sin(theta)**4 + 3 * c0_66 * cos(
                        theta)**4 - 2 * c0_66 * cos(theta)**2
Ejemplo n.º 12
0
    def __init__(self,
                 domain,
                 v_p,
                 v_s,
                 wavelet,
                 source_tag,
                 source_vector=[1., 0., 0.],
                 eps=0.,
                 gamma=0.,
                 delta=0.,
                 rho=1.,
                 dt=None,
                 u0=None,
                 v0=None,
                 absorption_zone=None,
                 absorption_cut=1e-2,
                 lumping=True,
                 disable_fast_assemblers=False):
        """
       initialize the VTI wave solver

       :param domain: domain of the problem
       :type domain: `Domain`
       :param v_p: vertical p-velocity field
       :type v_p: `escript.Scalar`
       :param v_s: vertical s-velocity field
       :type v_s: `escript.Scalar`
       :param wavelet: wavelet to describe the time evolution of source term
       :type wavelet: `Wavelet`
       :param source_tag: tag of the source location
       :type source_tag: 'str' or 'int'
       :param source_vector: source orientation vector
       :param eps: first Thompsen parameter
       :param delta: second Thompsen parameter
       :param gamma: third Thompsen parameter
       :param rho: density
       :param dt: time step size. If not present a suitable time step size is calculated.
       :param u0: initial solution. If not present zero is used.
       :param v0: initial solution change rate. If not present zero is used.
       :param absorption_zone: thickness of absorption zone
       :param absorption_cut: boundary value of absorption decay factor
       :param lumping: if True mass matrix lumping is being used. This is accelerates the computing but introduces some diffusion.
       :param disable_fast_assemblers: if True, forces use of slower and more general PDE assemblers
       """
        DIM = domain.getDim()
        self.fastAssembler = hasattr(
            domain, "createAssembler") and not disable_fast_assemblers
        f = createAbsorptionLayerFunction(v_p.getFunctionSpace().getX(),
                                          absorption_zone, absorption_cut)

        v_p = v_p * f
        v_s = v_s * f

        if u0 == None:
            u0 = escript.Vector(0., escript.Solution(domain))
        else:
            u0 = escript.interpolate(p0, escript.Solution(domain))

        if v0 == None:
            v0 = escript.Vector(0., escript.Solution(domain))
        else:
            v0 = escript.interpolate(v0, escript.Solution(domain))

        if dt == None:
            dt = min((1. / 5.) * min(escript.inf(domain.getSize() / v_p),
                                     escript.inf(domain.getSize() / v_s)),
                     wavelet.getTimeScale())

        super(HTIWave, self).__init__(dt, u0=u0, v0=v0, t0=0.)

        self.__wavelet = wavelet

        self.c33 = v_p**2 * rho
        self.c44 = v_s**2 * rho
        self.c11 = (1 + 2 * eps) * self.c33
        self.c66 = (1 + 2 * gamma) * self.c44
        self.c13 = escript.sqrt(2 * self.c33 * (self.c33 - self.c44) * delta +
                                (self.c33 - self.c44)**2) - self.c44
        self.c23 = self.c33 - 2 * self.c66

        if self.fastAssembler:
            C = [("c11", self.c11), ("c23", self.c23), ("c13", self.c13),
                 ("c33", self.c33), ("c44", self.c44), ("c66", self.c66)]
            if "speckley" in domain.getDescription().lower():
                C = [(n, escript.interpolate(d,
                                             escript.ReducedFunction(domain)))
                     for n, d in C]
            self.__mypde = lpde.WavePDE(domain, C)
        else:
            self.__mypde = lpde.LinearPDESystem(domain)
            self.__mypde.setValue(X=self.__mypde.createCoefficient('X'))

        if lumping:
            self.__mypde.getSolverOptions().setSolverMethod(
                lpde.SolverOptions.HRZ_LUMPING)
        self.__mypde.setSymmetryOn()
        self.__mypde.setValue(D=rho * escript.kronecker(DIM))
        self.__source_tag = source_tag

        if DIM == 2:
            source_vector = [source_vector[0], source_vector[2]]

        self.__r = escript.Vector(
            0, escript.DiracDeltaFunctions(self.__mypde.getDomain()))
        self.__r.setTaggedValue(self.__source_tag, source_vector)
Ejemplo n.º 13
0
    def __init__(self,
                 domain,
                 omega,
                 w,
                 data,
                 F,
                 coordinates=None,
                 fixAtBottom=False,
                 tol=1e-10,
                 saveMemory=True,
                 scaleF=True):
        """
        initializes a new forward model with acoustic wave form inversion.

        :param domain: domain of the model
        :type domain: `Domain`
        :param w: weighting factors
        :type w: ``Scalar``
        :param data: real and imaginary part of data
        :type data: ``escript.Data`` of shape (2,)
        :param F: real and imaginary part of source given at Dirac points,
                  on surface or at volume.
        :type F: ``escript.Data`` of shape (2,)
        :param coordinates: defines coordinate system to be used (not supported yet)
        :type coordinates: `ReferenceSystem` or `SpatialCoordinateTransformation`
        :param tol: tolerance of underlying PDE
        :type tol: positive ``float``
        :param saveMemory: if true stiffness matrix is deleted after solution
                           of PDE to minimize memory requests. This will
                           require more compute time as the matrix needs to be
                           reallocated.
        :type saveMemory: ``bool``
        :param scaleF: if true source F is scaled to minimize defect.
        :type scaleF: ``bool``
        :param fixAtBottom: if true pressure is fixed to zero at the bottom of
                            the domain
        :type fixAtBottom: ``bool``
        """
        super(AcousticWaveForm, self).__init__()
        self.__trafo = edc.makeTransformation(domain, coordinates)
        if not self.getCoordinateTransformation().isCartesian():
            raise ValueError(
                "Non-Cartesian Coordinates are not supported yet.")
        if not isinstance(data, escript.Data):
            raise ValueError("data must be an escript.Data object.")
        if not data.getFunctionSpace() == escript.FunctionOnBoundary(domain):
            raise ValueError("data must be defined on boundary")
        if not data.getShape() == (2, ):
            raise ValueError(
                "data must have shape (2,) (real and imaginary part).")
        if w is None:
            w = 1.
        if not isinstance(w, escript.Data):
            w = escript.Data(w, escript.FunctionOnBoundary(domain))
        else:
            if not w.getFunctionSpace() == escript.FunctionOnBoundary(domain):
                raise ValueError("Weights must be defined on boundary.")
            if not w.getShape() == ():
                raise ValueError("Weights must be scalar.")

        self.__domain = domain
        self.__omega = omega
        self.__weight = w
        self.__data = data
        self.scaleF = scaleF
        if scaleF:
            A = escript.integrate(self.__weight *
                                  escript.length(self.__data)**2)
            if A > 0:
                self.__data *= 1. / escript.sqrt(A)

        self.__BX = escript.boundingBox(domain)
        self.edge_lengths = np.asarray(escript.boundingBoxEdgeLengths(domain))

        if not isinstance(F, escript.Data):
            F = escript.interpolate(F, escript.DiracDeltaFunctions(domain))
        if not F.getShape() == (2, ):
            raise ValueError(
                "Source must have shape (2,) (real and imaginary part).")

        self.__F = escript.Data()
        self.__f = escript.Data()
        self.__f_dirac = escript.Data()

        if F.getFunctionSpace() == escript.DiracDeltaFunctions(domain):
            self.__f_dirac = F
        elif F.getFunctionSpace() == escript.FunctionOnBoundary(domain):
            self.__f = F
        else:
            self.__F = F
        self.__tol = tol
        self.__fixAtBottom = fixAtBottom
        self.__pde = None
        if not saveMemory:
            self.__pde = self.setUpPDE()
Ejemplo n.º 14
0
def RegionalCalculation(reg_mask):
    """
    Calculates the "regional" from the entire FEILDS model excluding the
    selected region and outputs gravity at the specified altitude...
    see above for the "residual"
    """

    # read in a gravity data grid to define data computation space
    G_DATA = os.path.join(DATADIR,'Final_BouguerTC_UC15K_qrtdeg.nc')
    FS=ReducedFunction(dom)
    nValues=[NX, NY, 1]
    first = [0, 0, cell_at_altitude]
    multiplier = [1, 1, 1]
    reverse = [0, 0, 0]
    byteorder = BYTEORDER_NATIVE
    gdata = readBinaryGrid(G_DATA, FS, shape=(),
                fill=-999999, byteOrder=byteorder,
                dataType=DATATYPE_FLOAT32, first=first, numValues=nValues,
                multiplier=multiplier, reverse=reverse)
    print("Grid successfully read")

    # get the masking and units sorted out for the data-space
    g_mask = whereNonZero(gdata+999999)

    gdata=gdata*g_mask * GRAV_UNITS

    # if people choose to have air in their region we exclude it from the
    # specified gravity calculation region
    if h_top < 0.:
        reg_mask = reg_mask+mask_air

    live_model = initial_model* whereNonPositive(reg_mask)
    dead_model = initial_model* wherePositive(reg_mask)

    if UseMean is True:
        # calculate the mean density within the selected region
        BackgroundDensity = integrate(dead_model)/integrate(wherePositive(reg_mask))
        print("Density mean for selected region equals = %s"%BackgroundDensity)

        live_model = live_model + BackgroundDensity * wherePositive(reg_mask)

    # create mapping
    rho_mapping = DensityMapping(dom, rho0=live_model)

    # invert sign of gravity field to account for escript's coordinate system
    gdata = -GRAV_UNITS * gdata

    # turn the scalars into vectors (vertical direction)
    d=kronecker(DIM)[DIM-1]
    w=safeDiv(1., g_mask)
    gravity_model=GravityModel(dom, w*d, gdata*d, fixPotentialAtBottom=False, coordinates=COORDINATES)
    gravity_model.rescaleWeights(rho_scale=rho_mapping.getTypicalDerivative())
    phi,_ = gravity_model.getArguments(live_model)
    g_init = -gravity_model.getCoordinateTransformation().getGradient(phi)
    g_init = interpolate(g_init, gdata.getFunctionSpace())
    print("Computed gravity: %s"%(g_init[2]))

    fn=os.path.join(OUTPUTDIR,'regional-gravity')
    if SiloOutput is True:
        saveSilo(fn, density=live_model, gravity_init=g_init, g_initz=-g_init[2], gravitymask=g_mask, modelmask=reg_mask)
        print('SILO file written with the following fields: density (kg/m^3), gravity vector (m/s^2), gz (m/s^2), gravitymask, modelmask')

    # to compare calculated data against input dataset.
    # Not used by default but should work if the input dataset is correct
    #gslice = g_init[2]*wherePositive(g_mask)
    #g_dash = integrate(gslice)/integrate(wherePositive(g_mask))
    #gdataslice = gdata*wherePositive(g_mask)
    #gdata_dash = integrate(gdataslice)/integrate(wherePositive(g_mask))
    #misfit=(gdataslice-gdata_dash)-(gslice-g_dash)
    saveDataCSV(fn+".csv", mask=g_mask, gz=-g_init[2], Long=datacoords[0], Lat=datacoords[1], h=datacoords[2])
    print('CSV file written with the following fields: Longitude (degrees) Latitude (degrees), h (100km), gz (m/s^2)')
    def getGradient(self, rho, Hx, g_Hx):
        """
        Returns the gradient of the defect with respect to resistivity.

        :param rho: a suggestion for resistivity
        :type rho: ``Data`` of shape ()
        :param Hx: magnetic field
        :type Hx: ``Data`` of shape (2,)
        :param g_Hx: gradient of magnetic field
        :type g_Hx: ``Data`` of shape (2,2)
        """
        pde = self.setUpPDE()
        DIM = self.getDomain().getDim()

        x = g_Hx.getFunctionSpace().getX()
        Hx = escript.interpolate(Hx, x.getFunctionSpace())
        u0 = Hx[0]
        u1 = Hx[1]
        u00 = g_Hx[0, 0]
        u10 = g_Hx[1, 0]
        u01 = g_Hx[0, 1]
        u11 = g_Hx[1, 1]

        A = pde.getCoefficient('A')
        D = pde.getCoefficient('D')
        Y = pde.getCoefficient('Y')
        X = pde.getCoefficient('X')

        for i in range(DIM):
            A[0, i, 0, i] = rho
            A[1, i, 1, i] = rho

        f = self._omega_mu
        D[0, 1] = f
        D[1, 0] = -f

        Z = self._Z
        scale = 1. / (u0**2 + u1**2)
        scale2 = scale**2
        scale *= self._weight
        scale2 *= rho * self._weight
        rho_scale = rho * scale

        gscale = u01**2 + u11**2

        Y[0] = scale2 * ((Z[0] * u01 + Z[1] * u11) *
                         (u0**2 - u1**2) + 2 * u0 * u1 *
                         (Z[0] * u11 - Z[1] * u01) - rho * u0 * gscale)
        Y[1] = scale2 * ((Z[0] * u11 - Z[1] * u01) *
                         (u1**2 - u0**2) + 2 * u0 * u1 *
                         (Z[0] * u01 + Z[1] * u11) - rho * u1 * gscale)
        X[0, 1] = rho_scale * (-Z[0] * u0 + Z[1] * u1 + rho * u01)
        X[1, 1] = rho_scale * (-Z[0] * u1 - Z[1] * u0 + rho * u11)

        pde.setValue(A=A, D=D, X=X, Y=Y)
        g = escript.grad(pde.getSolution())

        Hstarr_x = g[0, 0]
        Hstari_x = g[1, 0]
        Hstarr_z = g[0, 1]
        Hstari_z = g[1, 1]
        return -scale*(u0*(Z[0]*u01+Z[1]*u11)+u1*(Z[0]*u11-Z[1]*u01)-rho*gscale)\
               - Hstarr_x*u00 - Hstarr_z*u01 - Hstari_x*u10 - Hstari_z*u11