community: fix comments

Fix typos and revise Structure methods documentation.

community/louvain_common.go

@@ -47,10 +47,15 @@ type ReducedGraph interface {
 
 	// Structure returns the community structure of
 	// the current level of the module clustering.
-	// The first index of the returned value
-	// corresponds to the index of the nodes in the
-	// next higher level if it exists. The returned
-	// value should not be mutated.
+	// Each slice in the returned value recursively
+	// describes the membership of a community at
+	// the current level by indexing via the node
+	// ID into the structure of the non-nil
+	// ReducedGraph returned by Expanded, or when the
+	// ReducedGraph is nil, by containing nodes
+	// from the original input graph.
+	//
+	// The returned value should not be mutated.
 	Structure() [][]graph.Node
 
 	// Expanded returns the next lower level of the
@@ -150,10 +155,15 @@ type ReducedMultiplex interface {
 
 	// Structure returns the community structure of
 	// the current level of the module clustering.
-	// The first index of the returned value
-	// corresponds to the index of the nodes in the
-	// next higher level if it exists. The returned
-	// value should not be mutated.
+	// Each slice in the returned value recursively
+	// describes the membership of a community at
+	// the current level by indexing via the node
+	// ID into the structure of the non-nil
+	// ReducedGraph returned by Expanded, or when the
+	// ReducedGraph is nil, by containing nodes
+	// from the original input graph.
+	//
+	// The returned value should not be mutated.
 	Structure() [][]graph.Node
 
 	// Expanded returns the next lower level of the

community/louvain_directed.go

@@ -71,7 +71,7 @@ func qDirected(g graph.Directed, communities [][]graph.Node, resolution float64)
 
 // louvainDirected returns the hierarchical modularization of g at the given
 // resolution using the Louvain algorithm. If src is nil, rand.Intn is used
-// as the random generator. Louvain will panic if g has any edge with negative
+// as the random generator. louvainDirected will panic if g has any edge with negative
 // edge weight.
 func louvainDirected(g graph.Directed, resolution float64, src *rand.Rand) ReducedGraph {
 	// See louvain.tex for a detailed description
@@ -407,7 +407,7 @@ type directedLocalMover struct {
 
 	// nodes is the set of working nodes.
 	nodes []graph.Node
-	// edgeWeightOf is the weighted degree
+	// edgeWeightsOf is the weighted degree
 	// of each node indexed by ID.
 	edgeWeightsOf []directedWeights
 

community/louvain_test.go

@@ -29,7 +29,7 @@ func linksTo(i ...int) set {
 
 type layer struct {
 	g          []set
-	edgeWeight float64 // Zero edge weight is interpretted as 1.0.
+	edgeWeight float64 // Zero edge weight is interpreted as 1.0.
 	weight     float64
 }
 

community/louvain_undirected.go

@@ -69,7 +69,7 @@ func qUndirected(g graph.Undirected, communities [][]graph.Node, resolution floa
 
 // louvainUndirected returns the hierarchical modularization of g at the given
 // resolution using the Louvain algorithm. If src is nil, rand.Intn is used as
-// the random generator. Louvain will panic if g has any edge with negative edge
+// the random generator. louvainUndirected will panic if g has any edge with negative edge
 // weight.
 //
 // graph.Undirect may be used as a shim to allow modularization of directed graphs.