Exemplo n.º 1
0
    def test_compute_adjoint(self):
        "Test that we can compute the adjoint for some given functional"
        set_dolfin_parameters()
        model = Model()

        params = BasicSingleCellSolver.default_parameters()
        params["theta"] = theta
        time = Constant(0.0)
        solver = BasicSingleCellSolver(model, time, params=params)

        # Get initial conditions (Projection of expressions
        # don't get annotated, which is fine, because there is
        # no need.)
        ics = project(model.initial_conditions(), solver.VS)

        # Run forward model
        info_green("Running forward %s with theta %g" % (model, theta))
        self._run(solver, model, ics)

        (vs_, vs) = solver.solution_fields()

        # Define functional and compute gradient etc
        J = Functional(inner(vs_, vs_) * dx * dt[FINISH_TIME])

        # Compute adjoint
        info_green("Computing adjoint")
        z = compute_adjoint(J)

        # Check that no vs_ adjoint is None (== 0.0!)
        for (value, var) in z:
            if var.name == "vs_":
                msg = "Adjoint solution for vs_ is None (#fail)."
                assert (value is not None), msg
Exemplo n.º 2
0
    def test_compute_gradient(self):
        "Test that we can compute the gradient for some given functional"
        set_dolfin_parameters()
        model = Model()

        params = BasicSingleCellSolver.default_parameters()
        params["theta"] = theta
        time = Constant(0.0)
        solver = BasicSingleCellSolver(model, time, params=params)

        # Get initial conditions (Projection of expressions
        # don't get annotated, which is fine, because there is
        # no need.)
        ics = project(model.initial_conditions(), solver.VS)

        # Run forward model
        info_green("Running forward %s with theta %g" % (model, theta))
        self._run(solver, model, ics)

        # Define functional
        (vs_, vs) = solver.solution_fields()
        J = Functional(inner(vs, vs) * dx * dt[FINISH_TIME])

        # Compute gradient with respect to vs_. Highly unclear
        # why with respect to ics and vs fail.
        info_green("Computing gradient")
        dJdics = compute_gradient(J, Control(vs_))
        assert (dJdics is not None), "Gradient is None (#fail)."
        print(dJdics.vector().array())
Exemplo n.º 3
0
    def _run_solve(self, model, time, theta):
        "Run two time steps for the given model with the given theta solver."
        dt = 0.01
        T = 2 * dt
        interval = (0.0, T)

        # Initialize solver
        params = BasicSingleCellSolver.default_parameters()
        params["theta"] = theta

        params["enable_adjoint"] = False
        solver = BasicSingleCellSolver(model, time, params=params)

        # Assign initial conditions
        (vs_, vs) = solver.solution_fields()
        vs_.assign(model.initial_conditions())

        # Solve for a couple of steps
        solutions = solver.solve(interval, dt)
        for ((t0, t1), vs) in solutions:
            pass

        # Check that we are at the end time
        assert_almost_equal(t1, T, 1e-10)
        return vs.vector()
    def test_taylor_remainder(self):
        "Run Taylor remainder tests for selection of models and solvers."
        set_dolfin_parameters()
        model = Model()

        params = BasicSingleCellSolver.default_parameters()
        params["theta"] = theta
        time = Constant(0.0)
        solver = BasicSingleCellSolver(model, time, params=params)

        # Get initial conditions (Projection of expressions
        # don't get annotated, which is fine, because there is
        # no need.)
        ics = project(model.initial_conditions(), solver.VS)

        # Run forward model
        info_green("Running forward %s with theta %g" % (model, theta))
        self._run(solver, model, ics)

        # Define functional
        (vs_, vs) = solver.solution_fields()
        form = lambda w: inner(w, w)*dx
        J = Functional(form(vs)*dt[FINISH_TIME])

        # Compute value of functional with current ics
        Jics = assemble(form(vs))

        # Compute gradient with respect to vs_ (ics?)
        dJdics = compute_gradient(J, Control(vs_),
                                  forget=False)

        # Stop annotating
        parameters["adjoint"]["stop_annotating"] = True

        # Set-up runner
        def Jhat(ics):
            self._run(solver, model, ics)
            (vs_, vs) = solver.solution_fields()
            return assemble(form(vs))

        # Run taylor test
        if isinstance(model, Tentusscher_2004_mcell):
            seed=1.e-5
        else:
            seed=None

        conv_rate = taylor_test(Jhat, Control(vs_),
                                Jics, dJdics, seed=seed)

        # Check that minimal rate is greater than some given number
        assert_greater(conv_rate, 1.8)
    def test_replay(self):
        "Test that replay reports success for basic single cell solver"
        set_dolfin_parameters()
        model = Model()

        # Initialize solver
        params = BasicSingleCellSolver.default_parameters()
        params["theta"] = theta
        time = Constant(0.0)
        solver = BasicSingleCellSolver(model, time, params=params)

        info_green("Running %s with theta %g" % (model, theta))

        ics = project(model.initial_conditions(), solver.VS).copy(deepcopy=True, name="ics")
        self._run(solver, model, ics)

        info_green("Replaying")
        success = replay_dolfin(tol=0.0, stop=True)
        assert_true(success)
        def _run(cell):
            if dolfin_adjoint:
                from dolfin_adjoint import adj_reset
                adj_reset()

            solver = BasicSingleCellSolver(cell, Constant(0.0))

            # Setup initial condition
            (vs_, vs) = solver.solution_fields()
            vs_.vector()[0] = 30.  # Non-resting state
            vs_.vector()[1] = 0.

            T = 2
            solutions = solver.solve((0, T), 0.25)
            times = []
            v_values = []
            s_values = []
            for ((t0, t1), vs) in solutions:
                times += [0.5 * (t0 + t1)]
                v_values.append(vs.vector()[0])
                s_values.append(vs.vector()[1])

            return (v_values, s_values, times)
    def test_fitzhugh_nagumo_manual(self):
        """Test that the manually written FitzHugh-Nagumo model gives
        comparable results to a given reference from Sundnes et al,
        2006."""
        class Stimulus(Expression):
            def __init__(self, **kwargs):
                self.t = kwargs["t"]

            def eval(self, value, x):
                if float(self.t) >= 50 and float(self.t) < 60:
                    v_amp = 125
                    value[0] = 0.05 * v_amp
                else:
                    value[0] = 0.0

        if dolfin_adjoint:
            from dolfin_adjoint import adj_reset
            adj_reset()

        cell = FitzHughNagumoManual()
        time = Constant(0.0)
        cell.stimulus = Stimulus(t=time, degree=0)
        solver = BasicSingleCellSolver(cell, time)

        # Setup initial condition
        (vs_, vs) = solver.solution_fields()
        ic = cell.initial_conditions()
        vs_.assign(ic)

        # Initial set-up
        interval = (0, 400)
        dt = 1.0

        times = []
        v_values = []
        s_values = []

        # Solve
        solutions = solver.solve(interval, dt=dt)
        for (timestep, vs) in solutions:
            (t0, t1) = timestep
            times += [(t0 + t1) / 2]

            v_values += [vs.vector()[0]]
            s_values += [vs.vector()[1]]

        # Regression test
        v_max_reference = 2.6883308148064152e+01
        s_max_reference = 6.8660144687023219e+01
        tolerance = 1.e-14
        print "max(v_values) %.16e" % max(v_values)
        print "max(s_values) %.16e" % max(s_values)
        msg = "Maximal %s value does not match reference: diff is %.16e"

        v_diff = abs(max(v_values) - v_max_reference)
        s_diff = abs(max(s_values) - s_max_reference)
        assert (v_diff < tolerance), msg % ("v", v_diff)
        assert (s_diff < tolerance), msg % ("s", s_diff)

        # Correctness test
        import os
        if int(os.environ.get("DOLFIN_NOPLOT", 0)) != 1:
            import pylab
            pylab.plot(times, v_values, 'b*')
            pylab.plot(times, s_values, 'r-')