Update doc, remove mfem as dependency

.gitmodules

@@ -1,9 +1,6 @@
 [submodule "third-party/mmg"]
 	path = third-party/mmg
 	url = https://github.com/cbritopacheco/mmg
-[submodule "third-party/mfem"]
-	path = third-party/mfem
-	url = https://github.com/mfem/mfem/
 [submodule "third-party/corrade"]
 	path = third-party/corrade
 	url = https://github.com/mosra/corrade

doc/Doxygen.in

@@ -2311,7 +2311,7 @@ HIDE_UNDOC_RELATIONS   = YES
 # set to NO
 # The default value is: NO.
 
-HAVE_DOT               = NO
+HAVE_DOT               = YES
 
 # The DOT_NUM_THREADS specifies the number of dot invocations doxygen is allowed
 # to run in parallel. When set to 0 doxygen will base this on the number of
@@ -2331,14 +2331,14 @@ DOT_NUM_THREADS        = 0
 # The default value is: Helvetica.
 # This tag requires that the tag HAVE_DOT is set to YES.
 
-DOT_FONTNAME           = Helvetica
+DOT_FONTNAME           = Source Sans Pro
 
 # The DOT_FONTSIZE tag can be used to set the size (in points) of the font of
 # dot graphs.
 # Minimum value: 4, maximum value: 24, default value: 10.
 # This tag requires that the tag HAVE_DOT is set to YES.
 
-DOT_FONTSIZE           = 10
+DOT_FONTSIZE           = 16
 
 # By default doxygen will tell dot to use the default font as specified with
 # DOT_FONTNAME. If you specify a different font using DOT_FONTNAME you can set

doc/Examples/Variational/Elasticity.dox → doc/Examples/PDEs/Elasticity.dox

@@ -1,5 +1,5 @@
 /**
-  @page examples-variational-elasticity Solving the elasticity equation
+  @page examples-pdes-elasticity Solving the elasticity equation
   @brief Showcases the resolution of the elasticity system
 
   @image html Elasticity.png width=410px
@@ -14,7 +14,7 @@
   of the reference material in the introduction is taken from
   @cite allaire2021shape.
 
-  @section examples-variational-elasticity-intro Introduction
+  @section examples-pdes-elasticity-intro Introduction
 
   In the elasticity setting, we are most typically interested in characterizing
   the <em> elastic displacement </em> @f$ u_\Omega : \Omega \rightarrow
@@ -66,7 +66,7 @@
   @f$, @f$ \mu @f$ are the <em> Lamé parameters </em> of the constituent
   material, satisfying @f$ \mu > 0 @f$ and @f$ \lambda + 2\mu / d > 0 @f$.
   In general, as we have said in the
-  @ref examples-variational-poisson "Poisson example", we are mainly interested
+  @ref examples-pdes-poisson "Poisson example", we are mainly interested
   in the variational formulation of this equation. That is we seek to solve the
   problem:
   @f[
@@ -86,7 +86,7 @@
   theory. In this example we will be implementing the variational formulation
   using Rodin's @ref Rodin::Variational "Variational" module.
 
-  @section examples-variational-elasticity-impl Implementation
+  @section examples-pdes-elasticity-impl Implementation
 
   For simplicity, we will disregard any body forces by taking @f$ f = 0 @f$.
   In this vein, we also note that the integral in the variational formulation
@@ -153,7 +153,7 @@
   @endcode
 
   The full source code may be found below:
-  -   @ref Variational/Elasticity.cpp "Elasticity.cpp"
+  -   @ref PDEs/Elasticity.cpp "Elasticity.cpp"
 
-  @example Variational/Elasticity.cpp @m_examplenavigation{examples-variational-elasticity,Variational/} @m_footernavigation
+  @example PDEs/Elasticity.cpp @m_examplenavigation{examples-pdes-elasticity,PDEs/} @m_footernavigation
   */

doc/Examples/Variational/Poisson.dox → doc/Examples/PDEs/Poisson.dox

@@ -1,5 +1,5 @@
 /**
-  @page examples-variational-poisson Solving the Poisson equation
+  @page examples-pdes-poisson Solving the Poisson equation
   @brief Resolution of the Poisson equation using Rodin
 
   @image html Poisson.png width=410px
@@ -10,7 +10,7 @@
 
   @m_footernavigation
 
-  @section examples-variational-poisson-intro Introduction
+  @section examples-pdes-poisson-intro Introduction
 
   To introduce the Rodin::Variational module it is important to start from a
   type of "Hello World!" example. In this context, the Poisson equation fits
@@ -41,7 +41,7 @@
   literature. Hence we won't go into specifics. Rather, we deem it best to show
   how to implement said weak formulation and solve it.
 
-  @section examples-variational-poisson-preamble Includes and Namespaces
+  @section examples-pdes-poisson-preamble Includes and Namespaces
 
   In order to start using Rodin we first need to include the relevant parts
   which will aid us in the resolution of our equation. If you are familiar with
@@ -72,7 +72,7 @@ components:
   Rodin and Rodin::Variational namespaces to the global scope, so we don't have
   to write their namespace again.
 
-  @section examples-variational-poisson-impl Implementing the solution
+  @section examples-pdes-poisson-impl Implementing the solution
 
   Next we would like to write the code which actually solves the equation. For
   our purposes we will write it inside the `main` function like so:
@@ -183,7 +183,7 @@ components:
   @endcode
 
   The full source code may be found below:
-  -   @ref Variational/Poisson.cpp "Poisson.cpp"
+  -   @ref PDEs/Poisson.cpp "Poisson.cpp"
 
-  @example Variational/Poisson.cpp @m_examplenavigation{examples-variational-poisson,Variational/} @m_footernavigation
+  @example PDEs/Poisson.cpp @m_examplenavigation{examples-pdes-poisson,PDEs/} @m_footernavigation
   */

doc/Examples/Variational/SurfaceMeshes.dox → doc/Examples/PDEs/SurfaceMeshes.dox

@@ -1,5 +1,5 @@
 /**
-  @page examples-variational-surface_meshes Solving on surfaces with flat elements
+  @page examples-pdes-surface_meshes Solving on surfaces with flat elements
   @brief Showcases the resolution of Poisson equation with a mass term on the sphere
 
   @image html SurfaceMeshes.png width=410px
@@ -21,7 +21,7 @@
   elements.
 
   The full source code may be found below:
-  -   @ref Variational/SurfaceMeshes.cpp "SurfaceMeshes.cpp"
+  -   @ref PDEs/SurfaceMeshes.cpp "SurfaceMeshes.cpp"
 
-  @example Variational/SurfaceMeshes.cpp @m_examplenavigation{examples-variational-surface_meshes,Variational/} @m_footernavigation
+  @example PDEs/SurfaceMeshes.cpp @m_examplenavigation{examples-pdes-surface_meshes,PDEs/} @m_footernavigation
   */

doc/Examples/PDEsIndex.dox

@@ -0,0 +1,9 @@
+/**
+  @page examples-pdes-index Variational methods and weak formulations
+  @brief Showcases the usage of the Rodin::Variational module
+
+  - @subpage examples-pdes-poisson
+  - @subpage examples-pdes-elasticity
+  - @subpage examples-pdes-surface_meshes
+
+  */

doc/ExamplesIndex.dox

@@ -4,7 +4,7 @@
 
   @tableofcontents
 
-  @subsection examples-index-variational Variational methods
+  @subsection examples-index-variational Variational methods and weak formulations
 
   The Rodin::Variational module is mostly used when dealing with to variational
   problems of the form:
@@ -14,9 +14,9 @@
     a(u, v) = b(v) \ .
   @f]
 
-  For the complete list of examples go to the link below:
+  @subsection examples-index-pdes Solving PDEs
 
-  - @subpage examples-variational-index
+  - @subpage examples-pdes-index
 
   @subsection examples-index-solver Solving linear systems