add recursive clustering and skeletonization

Author: alexfikl

doc/conf.py

@@ -75,6 +75,7 @@
     "Discretization": "class:meshmode.discretization.Discretization",
     "DOFArray": "class:meshmode.dof_array.DOFArray",
     # boxtree
+    "Tree": "obj:boxtree.tree.Tree",
     "TreeKind": "obj:boxtree.tree_build.TreeKind",
     "FromSepSmallerCrit": "obj:boxtree.traversal.FromSepSmallerCrit",
     # sumpy
@@ -95,6 +96,7 @@
     "pytential.symbolic.dof_desc.DOFDescriptorLike":
         "data:pytential.symbolic.dof_desc.DOFDescriptorLike",
     "sym.DOFDescriptor": "class:pytential.symbolic.dof_desc.DOFDescriptor",
+    "sym.DOFDescriptorLike": "obj:pytential.symbolic.dof_desc.DOFDescriptorLike",
     "sym.IntG": "class:pytential.symbolic.primitives.IntG",
     "sym.var": "obj:pytential.symbolic.primitives.var",
 }

doc/linalg.rst

@@ -32,6 +32,7 @@ Low-level Functionality
     All the classes and routines in this module are experimental and the
     API can change at any point.
 
+.. automodule:: pytential.linalg.cluster
 .. automodule:: pytential.linalg.proxy
 .. automodule:: pytential.linalg.skeletonization