Merge pull request #770 from RemDelaporteMathurin/temperature-as-float

Temperature can be given as float or sp.Expr

docs/source/userguide/temperature.rst

@@ -3,7 +3,8 @@ Temperature
 ===========
 
 Definition of a temperature field or problem is essential for hydrogen transport 
-and FESTIM as a whole. 
+and FESTIM as a whole.
+Regardless of how you define the temperature of the problem, it is passed to the :code:`T` attribute of the :class:`festim.Simulation` object.
 
 ----------------------
 Analytical expressions
@@ -13,7 +14,7 @@ The temperature can be defined as a constant value in Kelvin (K):
 
 .. code-block:: python
 
-    my_temperature = Temperature(value=300)
+    my_temperature = 300
 
 
 Temperature can also be defined as an expression of time and/or space.
@@ -29,7 +30,7 @@ would be passed to FESTIM as:
 
     from festim import x, t
 
-    my_temp = Temperature(300+2*x+3*t)
+    my_temp = 300 + 2*x + 3*t
 
 More complex expressions can be expressed with sympy:
 
@@ -44,9 +45,16 @@ would be passed to FESTIM as:
     from festim import x, t
     import sympy as sp
 
-    my_temp = Temperature(sp.exp(x)*sp.sin(t))
+    my_temp = sp.exp(x) * sp.sin(t)
 
-For more details, see :class:`festim.Temperature`.
+Conditional expressions are also possible:
+
+.. code-block:: python
+
+    from festim import x, t
+    import sympy as sp
+
+    my_temp = sp.Piecewise((400, F.t < 10), (300, True))
 
 ---------------------------
 From a heat transfer solver

festim/generic_simulation.py

@@ -2,6 +2,7 @@
 from festim.h_transport_problem import HTransportProblem
 from fenics import *
 import numpy as np
+import sympy as sp
 import warnings
 
 
@@ -25,7 +26,7 @@ class Simulation:
             None.
         settings (festim.Settings, optional): The model's settings.
             Defaults to None.
-        temperature (festim.Temperature, optional): The model's
+        temperature (int, float, sympy.Expr, festim.Temperature, optional): The model's
             temperature. Can be an expression or a heat transfer model.
             Defaults to None.
         initial_conditions (list of festim.InitialCondition, optional):
@@ -164,6 +165,23 @@ def exports(self, value):
                 "accepted types for exports are list, festim.Export or festim.Exports"
             )
 
+    @property
+    def T(self):
+        return self._T
+
+    @T.setter
+    def T(self, value):
+        if isinstance(value, festim.Temperature):
+            self._T = value
+        elif value is None:
+            self._T = value
+        elif isinstance(value, (int, float, sp.Expr)):
+            self._T = festim.Temperature(value)
+        else:
+            raise TypeError(
+                "accepted types for T attribute are int, float, sympy.Expr or festim.Temperature"
+            )
+
     def attribute_source_terms(self):
         """Assigns the source terms (in self.sources) to the correct field
         (self.mobile, self.T, or traps)

test/simulation/test_initialise.py

@@ -1,6 +1,7 @@
 import festim as F
 from pathlib import Path
 import pytest
+import sympy as sp
 
 
 def test_initialise_changes_nb_of_sources():
@@ -149,6 +150,42 @@ def test_cartesian_and_surface_flux_warning(quantity, sys):
         my_model.initialise()
 
 
+@pytest.mark.parametrize(
+    "value",
+    [
+        100,
+        0,
+        100.0,
+        0.0,
+        100 + 1 * F.x,
+        0 + 1 * F.x,
+        F.x,
+        F.t,
+        sp.Piecewise((400, F.t < 10), (300, True)),
+    ],
+)
+def test_initialise_temp_as_number_or_sympy(value):
+    """
+    Creates a Simulation object and checks that the T attribute
+    can be given as an int, a float or a sympy Expr
+    """
+    # build
+    my_model = F.Simulation()
+    my_model.mesh = F.MeshFromVertices([1, 2, 3])
+    my_model.materials = F.Material(id=1, D_0=1, E_D=0)
+    my_model.T = value
+    my_model.settings = F.Settings(
+        absolute_tolerance=1e-10, relative_tolerance=1e-10, transient=False
+    )
+
+    # run
+    my_model.initialise()
+
+    # test
+    assert isinstance(my_model.T, F.Temperature)
+    assert my_model.T.value == value
+
+
 def test_error_is_raised_when_no_temp():
     """
     Creates a Simulation object and checks that an AttributeError is raised
@@ -170,6 +207,21 @@ def test_error_is_raised_when_no_temp():
         my_model.initialise()
 
 
+@pytest.mark.parametrize("value", ["coucou", [0, 0]])
+def test_wrong_type_temperature(value):
+    """
+    Creates a Simulation object and checks that a TypeError is raised
+    when the T attribute is given a value of the wrong type
+    """
+    my_model = F.Simulation()
+
+    with pytest.raises(
+        TypeError,
+        match="accepted types for T attribute are int, float, sympy.Expr or festim.Temperature",
+    ):
+        my_model.T = value
+
+
 def test_error_raised_when_no_final_time():
     """
     Creates a Simulation object and checks that a AttributeError is raised