add skipi_isolated param for louvain (#37)

Change-Id: Ib24ede9c20bb2c23a3f06fe72c53be2342295fd4
apache · Nov 1, 2022 · 7ecd6cb · 7ecd6cb
1 parent bd62bcb
commit 7ecd6cb
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Showing 3 changed files with 21 additions and 4 deletions.
diff --git a/hugegraph-core/src/main/java/com/baidu/hugegraph/job/algorithm/AbstractAlgorithm.java b/hugegraph-core/src/main/java/com/baidu/hugegraph/job/algorithm/AbstractAlgorithm.java
@@ -88,6 +88,7 @@ public abstract class AbstractAlgorithm implements Algorithm {
     public static final String KEY_PRECISION = "precision";
     public static final String KEY_SHOW_MOD= "show_modularity";
     public static final String KEY_SHOW_COMM = "show_community";
+    public static final String KEY_SKIP_ISOLATED = "skip_isolated";
     public static final String KEY_CLEAR = "clear";
     public static final String KEY_CAPACITY = "capacity";
     public static final String KEY_LIMIT = "limit";

diff --git a/hugegraph-core/src/main/java/com/baidu/hugegraph/job/algorithm/comm/LouvainAlgorithm.java b/hugegraph-core/src/main/java/com/baidu/hugegraph/job/algorithm/comm/LouvainAlgorithm.java
@@ -44,6 +44,7 @@ public void checkParameters(Map<String, Object> parameters) {
         sourceCLabel(parameters);
         showModularity(parameters);
         showCommunity(parameters);
+        skipIsolated(parameters);
         clearPass(parameters);
         workers(parameters);
     }
@@ -53,6 +54,7 @@ public Object call(UserJob<Object> job, Map<String, Object> parameters) {
         String label = sourceLabel(parameters);
         String clabel = sourceCLabel(parameters);
         long degree = degree(parameters);
+        boolean skipIsolated = skipIsolated(parameters);
         int workers = workers(parameters);
 
         Long clearPass = clearPass(parameters);
@@ -61,7 +63,7 @@ public Object call(UserJob<Object> job, Map<String, Object> parameters) {
 
         try (LouvainTraverser traverser = new LouvainTraverser(
                                           job, workers, degree,
-                                          label, clabel)) {
+                                          label, clabel, skipIsolated)) {
             if (clearPass != null) {
                 return traverser.clearPass(clearPass.intValue());
             } else if (modPass != null) {
@@ -96,4 +98,11 @@ protected static Long showModularity(Map<String, Object> parameters) {
         HugeTraverser.checkNonNegative(pass, KEY_SHOW_MOD);
         return pass;
     }
+
+    protected static boolean skipIsolated(Map<String, Object> parameters) {
+        if (!parameters.containsKey(KEY_SKIP_ISOLATED)) {
+            return true;
+        }
+        return ParameterUtil.parameterBoolean(parameters, KEY_SKIP_ISOLATED);
+    }
 }
diff --git a/hugegraph-core/src/main/java/com/baidu/hugegraph/job/algorithm/comm/LouvainTraverser.java b/hugegraph-core/src/main/java/com/baidu/hugegraph/job/algorithm/comm/LouvainTraverser.java
@@ -78,18 +78,22 @@ public class LouvainTraverser extends AlgoTraverser {
     private final String sourceLabel;
     private final String sourceCLabel;
     private final long degree;
+    private final boolean skipIsolated;
+
     private final Cache cache;
 
     private long m;
     private String passLabel;
 
     public LouvainTraverser(UserJob<Object> job, int workers, long degree,
-                            String sourceLabel, String sourceCLabel) {
+                            String sourceLabel, String sourceCLabel,
+                            boolean skipIsolated) {
         super(job, LouvainAlgorithm.ALGO_NAME, workers);
         this.g = this.graph().traversal();
         this.sourceLabel = sourceLabel;
         this.sourceCLabel = sourceCLabel;
         this.degree = degree;
+        this.skipIsolated = skipIsolated;
         this.m = 1L;
         this.passLabel = "";
 
@@ -355,6 +359,9 @@ private void doMoveCommunity(Vertex v, List<Edge> nbs, Community newC) {
     private boolean moveCommunity(Vertex v, int pass) {
         // move vertex to neighbor community if needed
         List<Edge> nbs = neighbors((Id) v.id());
+        if (this.skipIsolated && pass == 0 && nbs.isEmpty()) {
+            return false;
+        }
         Community c = communityOfVertex(v, nbs);
         double ki = kinOfVertex(v) + weightOfVertex(v, nbs);
         // update community of v if △Q changed
@@ -448,7 +455,7 @@ private void mergeCommunities(int pass) {
         LOG.info("Merge community for pass {}", pass);
         // merge each community as a vertex
         Collection<Pair<Community, Set<Id>>> comms = this.cache.communities();
-        assert this.allMembersExist(comms,  pass - 1);
+        assert this.skipIsolated || this.allMembersExist(comms,  pass - 1);
         this.cache.resetVertexWeight();
 
         Consumers<Pair<Community, Set<Id>>> consumers = new Consumers<>(
@@ -479,7 +486,7 @@ private void mergeCommunities(int pass) {
         }
 
         this.graph().tx().commit();
-        assert this.allMembersExist(pass);
+        assert this.skipIsolated || this.allMembersExist(pass);
 
         // reset communities
         this.cache.reset();