clean up the multigrid docs (#158)

This spreads them out across several notebooks and also cleans up the display.

Author: zingale

.github/workflows/pytest.yml

@@ -44,4 +44,4 @@ jobs:
         run: pip install .
 
       - name: Run tests with pytest
-        run: pytest -v --cov=pyro --nbval --ignore=docs --ignore=./pyro/multigrid/variable_coeff_elliptic.ipynb --ignore=examples/mesh --ignore=examples/multigrid --ignore=presentations
+        run: pytest -v --cov=pyro --nbval --ignore=docs --ignore=./pyro/multigrid/derive_analytic_solutions.ipynb --ignore=examples/mesh --ignore=examples/multigrid --ignore=presentations

docs/source/index.rst

@@ -33,8 +33,7 @@ pyro: a python hydro code
    burgers_basics
    compressible_basics
    compressible_compare
-   multigrid_basics
-   multigrid-examples.ipynb
+   multigrid
    diffusion_basics
    incompressible_basics
    lowmach_basics

docs/source/multigrid-constant-coefficients.ipynb

@@ -0,0 +1 @@
+../../pyro/multigrid/multigrid-constant-coefficients.ipynb

docs/source/multigrid-examples.ipynb

@@ -0,0 +1 @@
+../../pyro/multigrid/multigrid-general-linear.ipynb

docs/source/multigrid-general-linear.ipynb

@@ -0,0 +1 @@
+../../pyro/multigrid/multigrid-variable-coeff.ipynb

docs/source/multigrid-variable-coeff.ipynb

@@ -0,0 +1,10 @@
+Multigrid Solvers
+=================
+
+.. toctree::
+
+   multigrid_basics
+   multigrid-constant-coefficients
+   multigrid-variable-coeff
+   multigrid-general-linear
+   multigrid_exercises

docs/source/multigrid.rst

@@ -1,5 +1,5 @@
-Multigrid solvers
-=================
+Multigrid Class Overview
+========================
 
 pyro solves elliptic problems (like Laplace's equation or Poisson's
 equation) through multigrid. This accelerates the convergence of
@@ -30,8 +30,8 @@ there is no time-dependence in pure elliptic problems. Instead, there
 are a few scripts in the multigrid/ subdirectory that demonstrate its
 use.
 
-Examples
---------
+Simple Examples
+---------------
 
 multigrid test
 ^^^^^^^^^^^^^^
@@ -123,21 +123,3 @@ results are shown below:
 Left is the original u velocity, middle is the modified field after adding the gradient of the scalar, and right is the recovered field.
 
 
-Exercises
----------
-
-Explorations
-^^^^^^^^^^^^
-
-* Try doing just smoothing, no multigrid. Show that it still converges
-  second order if you use enough iterations, but that the amount of
-  time needed to get a solution is much greater.
-
-Extensions
-^^^^^^^^^^
-
-* Implement inhomogeneous dirichlet boundary conditions
-
-* Add a different bottom solver to the multigrid algorithm
-
-* Make the multigrid solver work for non-square domains

docs/source/multigrid_basics.rst

@@ -0,0 +1,18 @@
+Exercises
+=========
+
+Explorations
+------------
+
+* Try doing just smoothing, no multigrid. Show that it still converges
+  second order if you use enough iterations, but that the amount of
+  time needed to get a solution is much greater.
+
+Extensions
+----------
+
+* Add a different bottom solver to the multigrid algorithm
+
+* Make the multigrid solver work for non-square domains
+
+* Implement the full-multigrid algorithm instead of just V-cycles