Naive VR implementation for internal use.

1 files changed, 28 insertions, 2 deletions

diff --git a/phstuff/simplicial.py b/phstuff/simplicial.py
index 884a543..6614bf7 100644
--- a/phstuff/simplicial.py
+++ b/phstuff/simplicial.py
@@ -1,3 +1,6 @@
+import numpy as np
+import itertools
+
 class Node:
     def __init__(self, x, i, w, parent):
         self.x = x
@@ -132,13 +135,36 @@ class Complex:
         
         return parent.children.setdefault(last, node)
 
-
     def __contains__(self, simplex):
         return self.find(simplex) is not None
 
     def __iter__(self):
         return ComplexIterator(self.__root)
 
+    def __len__(self):
+        return self.__count
 
-        
+# Very naive temporary VR implementations.
+def naive_vr_tmp(graph, top_dim):
+    assert(graph.shape[0] == graph.shape[1])
+
+    vertex_set = np.arange(0, graph.shape[0])
+    cplx = Complex()
+    for p in range(0, top_dim):
+        to_add = itertools.combinations(vertex_set, p+1)
+        if p == 0:
+            for v in vertex_set:
+                cplx.add([v], 0.0)
+        elif p == 1:
+            for simplex in to_add:
+                cplx.add(simplex, graph[simplex[0], simplex[1]])
+        else:
+            for simplex in to_add:
+                codim1faces = itertools.combinations(simplex, p)
+                weight = 0.0
+                for face in codim1faces:
+                    weight = max(cplx.find(face).w, weight)
+                cplx.add(simplex, weight)
             
+        
+    return cplx