adding arithmetic for hypergraphs

hypernetx/classes/hypergraph.py

@@ -2040,3 +2040,89 @@ def from_incidence_dataframe(
             return dfnew
         else:
             return Hypergraph(dfnew, cell_weight_col="weight", name=name, **kwargs)
+
+    def __add__(self,other):
+        """
+        Concatenate incidences from two hypergraphs, removing duplicates and
+        dropping duplicate property data in the order of addition.
+
+        Parameters
+        ----------
+        other : Hypergraph
+
+        Returns
+        -------
+        Hypergraph
+            
+        """    
+        return self.sum(other)
+
+    def __sub__(self,other):
+        """
+        Concatenate incidences from two hypergraphs, removing duplicates and
+        dropping duplicate property data in the order of addition.
+
+        Parameters
+        ----------
+        other : Hypergraph
+
+        Returns
+        -------
+        Hypergraph
+            
+        """  
+        return self.difference(other)
+
+    def sum(self,other):
+        """
+        Concatenate incidences from two hypergraphs, removing duplicates and
+        dropping duplicate property data in the order of addition.
+
+        Parameters
+        ----------
+        other : Hypergraph
+
+        Returns
+        -------
+        Hypergraph
+            
+        """
+        df = self.dataframe
+        odf = other.dataframe
+        ndf = pd.concat([df,odf]).groupby(['edges','nodes']).agg('first')    
+        edf = self.edges.dataframe
+        oedf = other.edges.dataframe
+        nedf = pd.concat([edf,oedf]).groupby('uid').agg('first')    
+        nddf = self.nodes.dataframe
+        onddf = other.nodes.dataframe
+        nnddf = pd.concat([nddf,onddf]).groupby('uid').agg('first')    
+        return self._construct_hyp_from_stores(ndf,edge_ps=PropertyStore(nedf),node_ps=PropertyStore(nnddf))
+
+    def difference(self,other):
+        """
+        Concatenate incidences from two hypergraphs, removing duplicates and
+        dropping duplicate property data in the order of addition.
+
+        Parameters
+        ----------
+        other : Hypergraph
+
+        Returns
+        -------
+        Hypergraph
+            
+        """
+        df = self.incidences.properties
+        odf = other.incidences.properties
+        ndf = df.loc[~df.index.isin(odf.index.tolist())]    
+        edf = self.edges.properties
+        oedf = other.edges.properties
+        nedf = edf.loc[~edf.index.isin(oedf.index.tolist())]    
+        nddf = self.nodes.properties
+        onddf = other.nodes.properties
+        nnddf = nddf.loc[~nddf.index.isin(onddf.index.tolist())]   
+        return self._construct_hyp_from_stores(ndf,edge_ps=PropertyStore(nedf),node_ps=PropertyStore(nnddf))
+
+
+
+