Settings and Stepsize classes

festim/__init__.py

@@ -28,10 +28,14 @@
 
 from .hydrogen_transport_problem import HydrogenTransportProblem
 
+from .settings import Settings
+
 from .species import Species, Trap
 
 from .subdomain.surface_subdomain import SurfaceSubdomain1D
 from .subdomain.volume_subdomain import VolumeSubdomain1D
 
+from .stepsize import Stepsize
+
 from .exports.vtx import VTXExport
 from .exports.xdmf import XDMFExport

festim/hydrogen_transport_problem.py

@@ -77,7 +77,7 @@ def __init__(
         temperature=None,
         sources=[],
         boundary_conditions=[],
-        solver_parameters=None,
+        settings=None,
         exports=[],
     ) -> None:
         self.mesh = mesh
@@ -86,7 +86,7 @@ def __init__(
         self.temperature = temperature
         self.sources = sources
         self.boundary_conditions = boundary_conditions
-        self.solver_parameters = solver_parameters
+        self.settings = settings
         self.exports = exports
 
         self.dx = None
@@ -115,6 +115,7 @@ def initialise(self):
         self.assign_functions_to_species()
 
         self.t = fem.Constant(self.mesh.mesh, 0.0)
+        self.dt = self.settings.stepsize.get_dt(self.mesh.mesh)
 
         self.define_boundary_conditions()
         self.create_formulation()
@@ -218,11 +219,6 @@ def create_formulation(self):
         if len(self.species) > 1:
             raise NotImplementedError("Multiple species not implemented yet")
 
-        # TODO expose dt as parameter of the model
-        dt = fem.Constant(self.mesh.mesh, 1 / 20)
-
-        self.dt = dt  # TODO remove this
-
         self.formulation = 0
 
         for spe in self.species:
@@ -236,7 +232,7 @@ def create_formulation(self):
                 )
 
                 self.formulation += dot(D * grad(u), grad(v)) * self.dx(vol.id)
-                self.formulation += ((u - u_n) / dt) * v * self.dx(vol.id)
+                self.formulation += ((u - u_n) / self.dt) * v * self.dx(vol.id)
 
                 # add sources
                 # TODO implement this
@@ -258,15 +254,14 @@ def create_solver(self):
             self.species[0].solution,
             bcs=self.bc_forms,
         )
-        solver = NewtonSolver(MPI.COMM_WORLD, problem)
-        self.solver = solver
+        self.solver = NewtonSolver(MPI.COMM_WORLD, problem)
+        self.solver.atol = self.settings.atol
+        self.solver.rtol = self.settings.rtol
+        self.solver.max_it = self.settings.max_iterations
 
-    def run(self, final_time: float):
+    def run(self):
         """Runs the model for a given time
 
-        Args:
-            final_time (float): the final time of the simulation
-
         Returns:
             list of float: the times of the simulation
             list of float: the fluxes of the simulation
@@ -279,9 +274,11 @@ def run(self, final_time: float):
         )
         cm = self.species[0].solution
         progress = tqdm.autonotebook.tqdm(
-            desc="Solving H transport problem", total=final_time
+            desc="Solving H transport problem",
+            total=self.settings.final_time,
+            unit_scale=True,
         )
-        while self.t.value < final_time:
+        while self.t.value < self.settings.final_time:
             progress.update(self.dt.value)
             self.t.value += self.dt.value
 

festim/settings.py

@@ -0,0 +1,53 @@
+import festim as F
+
+
+class Settings:
+    """Settings for a festim simulation.
+
+    Args:
+        atol (float): Absolute tolerance for the solver.
+        rtol (float): Relative tolerance for the solver.
+        max_iterations (int, optional): Maximum number of iterations for the
+            solver. Defaults to 30.
+        final_time (float, optional): Final time for a transient simulation.
+            Defaults to None
+        stepsize (festim.Stepsize, optional): stepsize for a transient
+            simulation. Defaults to None
+
+    Attributes:
+        atol (float): Absolute tolerance for the solver.
+        rtol (float): Relative tolerance for the solver.
+        max_iterations (int, optional): Maximum number of iterations for the solver.
+        final_time (float, optional): Final time for a transient simulation.
+        stepsize (festim.Stepsize, optional): stepsize for a transient
+            simulation.
+    """
+
+    def __init__(
+        self,
+        atol,
+        rtol,
+        max_iterations=30,
+        final_time=None,
+        stepsize=None,
+    ) -> None:
+        self.atol = atol
+        self.rtol = rtol
+        self.max_iterations = max_iterations
+        self.final_time = final_time
+        self.stepsize = stepsize
+
+    @property
+    def stepsize(self):
+        return self._stepsize
+
+    @stepsize.setter
+    def stepsize(self, value):
+        if value is None:
+            self._stepsize = None
+        elif isinstance(value, (float, int)):
+            self._stepsize = F.Stepsize(initial_value=value)
+        elif isinstance(value, F.Stepsize):
+            self._stepsize = value
+        else:
+            raise TypeError("stepsize must be an of type int, float or festim.Stepsize")

festim/stepsize.py

@@ -0,0 +1,28 @@
+import festim as F
+
+
+class Stepsize:
+    """
+    A class for evaluating the stepsize of transient simulations.
+
+    Args:
+        initial_value (float, int): initial stepsize.
+
+    Attributes:
+        initial_value (float, int): initial stepsize.
+    """
+
+    def __init__(
+        self,
+        initial_value,
+    ) -> None:
+        self.initial_value = initial_value
+
+    def get_dt(self, mesh):
+        """Defines the dt value
+        Args:
+            mesh (dolfinx.mesh.Mesh): the domain mesh
+        Returns:
+            fem.Constant: the dt value
+        """
+        return F.as_fenics_constant(self.initial_value, mesh)

test/benchmark.py

@@ -133,7 +133,7 @@ def siverts_law(T, S_0, E_S, pressure):
     times = []
     t = 0
     progress = tqdm.autonotebook.tqdm(
-        desc="Solving H transport problem", total=final_time
+        desc="Solving H transport problem", total=final_time, unit_scale=True
     )
     while t < final_time:
         progress.update(float(dt))

test/test_dirichlet_bc.py

@@ -281,13 +281,16 @@ def test_integration_with_HTransportProblem(value):
 
     my_model.temperature = fem.Constant(my_model.mesh.mesh, 550.0)
 
+    my_model.settings = F.Settings(atol=1, rtol=0.1, final_time=2)
+    my_model.settings.stepsize = F.Stepsize(initial_value=1)
+
     # RUN
 
     my_model.initialise()
 
     assert my_bc.value_fenics is not None
 
-    my_model.run(final_time=2)
+    my_model.run()
 
     # TEST
 

test/test_permeation_problem.py

@@ -35,13 +35,18 @@ def test_permeation_problem(mesh_size=1001):
     ]
     my_model.exports = [F.XDMFExport("mobile_concentration.xdmf", field=mobile_H)]
 
+    my_model.settings = F.Settings(
+        atol=1e10,
+        rtol=1e-10,
+        max_iterations=30,
+        final_time=50,
+    )
+
+    my_model.settings.stepsize = F.Stepsize(initial_value=1 / 20)
+
     my_model.initialise()
 
     my_model.solver.convergence_criterion = "incremental"
-    my_model.solver.rtol = 1e-10
-    my_model.solver.atol = 1e10
-
-    my_model.solver.report = True
     ksp = my_model.solver.krylov_solver
     opts = PETSc.Options()
     option_prefix = ksp.getOptionsPrefix()
@@ -50,9 +55,7 @@ def test_permeation_problem(mesh_size=1001):
     opts[f"{option_prefix}pc_factor_mat_solver_type"] = "mumps"
     ksp.setFromOptions()
 
-    final_time = 50
-
-    times, flux_values = my_model.run(final_time=final_time)
+    times, flux_values = my_model.run()
 
     # -------------------------- analytical solution -------------------------------------
 
@@ -126,13 +129,18 @@ def test_permeation_problem_multi_volume():
     ]
     my_model.exports = [F.VTXExport("test.bp", field=mobile_H)]
 
+    my_model.settings = F.Settings(
+        atol=1e10,
+        rtol=1e-10,
+        max_iterations=30,
+        final_time=50,
+    )
+
+    my_model.settings.stepsize = F.Stepsize(initial_value=1 / 20)
+
     my_model.initialise()
 
     my_model.solver.convergence_criterion = "incremental"
-    my_model.solver.rtol = 1e-10
-    my_model.solver.atol = 1e10
-
-    my_model.solver.report = True
     ksp = my_model.solver.krylov_solver
     opts = PETSc.Options()
     option_prefix = ksp.getOptionsPrefix()
@@ -141,9 +149,7 @@ def test_permeation_problem_multi_volume():
     opts[f"{option_prefix}pc_factor_mat_solver_type"] = "mumps"
     ksp.setFromOptions()
 
-    final_time = 50
-
-    times, flux_values = my_model.run(final_time=final_time)
+    times, flux_values = my_model.run()
 
     # -------------------------- analytical solution -------------------------------------
     D = my_mat.get_diffusion_coefficient(my_mesh.mesh, temperature)

test/test_settings.py

@@ -0,0 +1,21 @@
+import festim as F
+import numpy as np
+import pytest
+
+
+@pytest.mark.parametrize("value", [1, F.Stepsize(initial_value=23.0), 1.0, "coucou"])
+def test_stepsize_value(value):
+    """Test that the stepsize is correctly set"""
+    my_model = F.HydrogenTransportProblem()
+    my_model.settings = F.Settings(atol=1, rtol=0.1)
+
+    if isinstance(value, (int, float)):
+        my_model.settings.stepsize = value
+        assert isinstance(my_model.settings.stepsize, F.Stepsize)
+        assert np.isclose(my_model.settings.stepsize.initial_value, value)
+    elif isinstance(value, F.Stepsize):
+        my_model.settings.stepsize = value
+        assert np.isclose(my_model.settings.stepsize.initial_value, 23)
+    else:
+        with pytest.raises(TypeError):
+            my_model.settings.stepsize = value

test/test_sievertsbc.py

@@ -93,10 +93,13 @@ def test_integration_with_HTransportProblem(pressure):
 
     my_model.temperature = fem.Constant(my_model.mesh.mesh, 550.0)
 
+    my_model.settings = F.Settings(atol=1, rtol=0.1, final_time=2)
+    my_model.settings.stepsize = F.Stepsize(initial_value=1)
+
     # RUN
 
     my_model.initialise()
 
     assert my_bc.value_fenics is not None
 
-    my_model.run(final_time=2)
+    my_model.run()

test/test_vtx.py

@@ -60,6 +60,8 @@ def test_vtx_integration_with_h_transport_problem(tmpdir):
     filename = str(tmpdir.join("my_export.bp"))
     my_export = F.VTXExport(filename, field=my_model.species[0])
     my_model.exports = [my_export]
+    my_model.settings = F.Settings(atol=1, rtol=0.1)
+    my_model.settings.stepsize = F.Stepsize(initial_value=1)
 
     my_model.initialise()
 

test/test_xdmf.py

@@ -47,8 +47,10 @@ def test_integration_with_HTransportProblem(tmp_path):
     filename = os.path.join(tmp_path, "test.xdmf")
     my_model.exports = [F.XDMFExport(filename=filename, field=my_model.species)]
 
+    my_model.settings = F.Settings(atol=1, rtol=0.1, final_time=1)
+    my_model.settings.stepsize = F.Stepsize(initial_value=0.5)
     my_model.initialise()
-    my_model.run(1)
+    my_model.run()
 
     # checks that filename exists
     assert os.path.exists(filename)