Homophily inference

docs/source/graphs.rst

@@ -1,6 +1,9 @@
 Graphs
 =======
 
+.. autoclass:: netin.Graph
+    :members:
+
 .. toctree::
    :maxdepth: 2
    :caption: Contents:

netin/generators/graph.py

@@ -73,7 +73,6 @@ def __init__(self, n: int, f_m: float, seed: object = None):
         self.node_class_values = None  # dictionary of node class values
         self.gen_start_time = None  # start time of the generation
         self.gen_duration = None  # duration of the generation
-
     ############################################################
     # Init
     ############################################################
@@ -921,6 +920,35 @@ def copy(self) -> Union[nx.Graph, nx.DiGraph]:
         g.n_M = self.n_M
         return g
 
+    def homophily_inference(self) -> float:
+        """
+        Calculates the inferred homophily based on https://arxiv.org/abs/2401.13642
+
+        ##Experimental: For now only undirected and canonical
+
+        Returns
+        -------
+        h_infer: float
+            Inferred homophily
+        Raises
+        ------
+        NotImplementedError
+            If the graph is directed
+        """
+        e = self.calculate_edge_type_counts()
+
+        if self.is_directed():
+            raise NotImplementedError("This function only supports undirected graphs")
+
+        else:
+            e_rs = e['mM'] + e['Mm']
+            e_rr = 2 * e['MM']
+            e_ss = 2 * e['mm']
+            alpha = e_rs / np.sqrt(e_rr * e_ss)
+
+            h_infer = 1 / (1 + alpha)
+
+        return h_infer
 
 ######################################################################################################################
 # Static functions

netin/generators/tests/test_homophily_inference.py

@@ -0,0 +1,70 @@
+from netin import PA
+from netin import PAH
+from netin import PATC
+from netin import PATCH
+from netin.utils import constants as const
+import netin
+import numpy as np
+
+
+class TestHomophilyInference(object):
+
+    def test_patch_case_pah(self):
+        n = 1000
+        k = 2
+        f_m = 0.1
+        h_MM = 0.7
+        h_mm = 0.7
+        # seed = 1234
+        # g = netin.PAH(n=n, k=k, f_m=f_m, h_MM=h_MM, h_mm=h_mm, seed=seed)
+        g = netin.PAH(n=n, k=k, f_m=f_m, h_MM=h_MM, h_mm=h_mm)
+        g.generate()
+        inferred_homophily = g.homophily_inference()
+
+        c1 = np.abs( inferred_homophily - h_MM ) < 0.1
+
+        assert c1, "Incorrect value of homophily inference"
+
+    def test_patch_case_pah_neutral(self):
+        n = 1000
+        k = 2
+        f_m = 0.1
+        h_MM = 0.5  # Changed from 0.7 to 0.5
+        h_mm = 0.5  # Changed from 0.7 to 0.5
+        g = netin.PAH(n=n, k=k, f_m=f_m, h_MM=h_MM, h_mm=h_mm)
+        g.generate()
+        inferred_homophily = g.homophily_inference()
+
+        c1 = np.abs(inferred_homophily - h_MM) < 0.1
+
+        assert c1, "Incorrect value of homophily inference"
+
+
+    def test_patch_case_pa(self):
+        n = 2000  # Increased network size
+        k = 4  # Increased average degree
+        f_m = 0.15
+        # h_MM = 0.8
+        # h_mm = 0.8
+        g = netin.PA(n=n, k=k, f_m=f_m)
+        g.generate()
+        inferred_homophily = g.homophily_inference()
+
+        c1 = np.abs(inferred_homophily - 0.5) < 0.1
+
+        assert c1, "Incorrect value of homophily inference"
+
+
+    def test_patch_case_patch_hetero(self):
+        n = 2000  # Increased network size
+        k = 4  # Increased average degree
+        f_m = 0.15
+        h_MM = 0.3
+        h_mm = 0.3
+        g = netin.PATCH(n=n, k=k, f_m=f_m, h_MM=h_MM, h_mm=h_mm, tc = 0.0)
+        g.generate()
+        inferred_homophily = g.homophily_inference()
+
+        c1 = np.abs(inferred_homophily - h_mm) < 0.1
+
+        assert c1, "Incorrect value of homophily inference"