Add transient to docs

docs/source/api.rst

@@ -1,12 +1,15 @@
 API
 ===
 
-EchemSolver class
------------------
+EchemSolver classes
+-------------------
 
 .. autoclass:: echemfem.EchemSolver
    :members:
 
+.. autoclass:: echemfem.TransientEchemSolver
+   :members:
+
 Utility meshes
 --------------
 These are boundary layer meshes, which are modified versions of :func:`firedrake.utility_meshes.IntervalMesh` and :func:`firedrake.utility_meshes.RectangleMesh`.

docs/source/conf.py

@@ -23,6 +23,7 @@
 
 intersphinx_mapping = {
     'python': ('https://docs.python.org/3/', None),
+    'numpy': ('https://docs.scipy.org/doc/numpy/', None),
     'sphinx': ('https://www.sphinx-doc.org/en/master/', None),
     'firedrake': ('https://firedrakeproject.org/', None),
 }
@@ -36,3 +37,4 @@
 
 # -- Options for EPUB output
 epub_show_urls = 'footnote'
+

docs/source/user_guide/index.rst

@@ -9,7 +9,13 @@ The first step of writing an EchemFEM script is to import the ``EchemSolver`` cl
 
    from echemfem import EchemSolver
 
-This is an abstract class, which we will use as the base class for a specific model.
+or for a transient simulation, the ``TransientEchemSolver`` class:
+
+.. code-block::
+
+   from echemfem import TransientEchemSolver
+
+These are abstract classes, which we will use as the base class for a specific model.
 To create a customized solver, the user should set the following inputs:
 
 .. toctree::
@@ -20,3 +26,36 @@ To create a customized solver, the user should set the following inputs:
    boundary_conditions
    echem_params
 
+Here is a barebone example of how a user might define their own solver.
+Several concrete examples can be found in `echemfem/examples
+<https://github.com/LLNL/echemfem/tree/main/examples>`_.
+
+.. code-block::
+
+    class MySolver(EchemSolver): # or TransientEchemSolver
+
+        def __init__(self):
+            # Here define all custom parameters that may require attributes
+
+            super().__init__(...) # with appropriate arguments
+
+        def set_boundary_markers(self):
+            self.boundary_markers = ...
+
+        # and some other methods that need to be defined
+
+Then, to run the simulation, create the object and run the ``solve`` method.
+
+.. code-block::
+
+   solver = MySolver()
+   solver.solve()
+
+For transient cases, a temporal grid defined as a  ``list`` or
+``numpy.ndarray`` must be provided. For example,
+
+.. code-block::
+
+   import numpy as np
+   times = np.linspace(0, 11, 1)  # 10 timesteps of size 0.1
+   solver.solve(times)

echemfem/solver.py

@@ -2605,7 +2605,7 @@ def solve(self, times):
         """Solves the transient problem and outputs the solutions
 
         Args:
-            times (list or numpy.array): array of the discrete temporal grid
+            times (list or :class:`numpy.ndarray`): array of the discrete temporal grid
 
         """