fix: avoid complex calculation when inertialModularity disabled

package.json

@@ -15,5 +15,6 @@
   },
   "devDependencies": {
     "lerna": "^3.20.2"
-  }
-}
+  },
+  "repository": "https://github.com/antvis/algorithm.git"
+}

packages/graph/benchmarks/louvain.js

@@ -0,0 +1,98 @@
+/**
+ * Graphology x 173,947 ops/sec ±0.22% (98 runs sampled)
+ * NGraph x 60,245 ops/sec ±0.24% (99 runs sampled)
+ * @antv/algorithm x 436 ops/sec ±0.53% (85 runs sampled)
+ * Fastest is Graphology
+ */
+var Benchmark = require('benchmark');
+var suite = new Benchmark.Suite();
+
+/**
+ * Graphology
+ * @see https://graphology.github.io/standard-library/communities-louvain.html
+ */
+var louvain = require('graphology-communities-louvain');
+
+/**
+ * @antv/algorithm
+ * @see https://g6.antv.antgroup.com/api/algorithm#louvain
+ */
+var Algorithm = require('../lib');
+
+/**
+ * ngraph.louvain
+ * @see https://github.com/anvaka/ngraph.louvain
+ */
+var createNGraph = require('ngraph.graph');
+var ngraphLouvain = require('ngraph.louvain');
+var ngraphCoarsen = require('ngraph.coarsen');
+var nGraph = createNGraph();
+function collectNGraphCommunities(g, result) {
+  var map = {};
+  g.forEachNode((n) => {
+    map[n.id] = result.getClass(n.id);
+  });
+  return map;
+}
+function ngraphLouvainHierarchy(g) {
+  var clusters = ngraphLouvain(g);
+  while (clusters.canCoarse()) {
+    g = ngraphCoarsen(g, clusters);
+    clusters = ngraphLouvain(g);
+  }
+  return collectNGraphCommunities(g, clusters);
+}
+
+/**
+ * Generate graph with clusters.
+ */
+var Graph = require('graphology');
+var randomClusters = require('graphology-generators/random/clusters');
+var seedrandom = require('seedrandom');
+var rng = function () {
+  return seedrandom('bench');
+};
+const NODE_NUM = 10;
+const EDGE_NUM = 30;
+const g6graph = { nodes: [], edges: [] };
+var graph = randomClusters(Graph, {
+  order: NODE_NUM,
+  size: EDGE_NUM,
+  clusters: 5,
+  rng: rng(),
+});
+graph.nodes().forEach(function (node) {
+  nGraph.addNode(node);
+  g6graph.nodes.push({ id: node });
+});
+graph.edges().forEach(function (edge) {
+  graph.setEdgeAttribute(edge, 'weight', 1);
+  const source = graph.source(edge);
+  const target = graph.target(edge);
+  nGraph.addLink(source, target);
+  g6graph.edges.push({ source, target, weight: 1 });
+});
+
+function distinctSize(o) {
+  var keys = new Set();
+  for (var k in o) keys.add(o[k]);
+  return keys.size;
+}
+
+suite
+  .add('Graphology', function () {
+    const clusters = louvain(graph);
+  })
+  .add('NGraph', function () {
+    const clusters = ngraphLouvainHierarchy(nGraph);
+  })
+  .add('@antv/algorithm', function () {
+    const clusters = Algorithm.louvain(g6graph, false);
+  })
+  .on('cycle', function (event) {
+    console.log(String(event.target));
+  })
+  .on('complete', function () {
+    console.log('Fastest is ' + this.filter('fastest').map('name'));
+  })
+  .run({ async: true });

packages/graph/package.json

@@ -34,7 +34,8 @@
     "test-live": "npm run build:umd && DEBUG_MODE=1 jest --watch ./tests/unit/louvain-spec.ts",
     "test-live:async": "npm run build:umd && DEBUG_MODE=1 jest --watch ./tests/unit/louvain-async-spec.ts",
     "lint-staged:js": "eslint --ext .js,.jsx,.ts,.tsx",
-    "cdn": "antv-bin upload -n @antv/algorithm"
+    "cdn": "antv-bin upload -n @antv/algorithm",
+    "benchmark": "node benchmarks/louvain.js"
   },
   "homepage": "https://g6.antv.vision",
   "bugs": {
@@ -54,6 +55,16 @@
     "@types/jest": "^26.0.18",
     "@umijs/fabric": "^2.5.6",
     "babel-loader": "^8.2.2",
+    "benchmark": "^2.1.4",
+    "graphology": "^0.25.1",
+    "graphology-communities-louvain": "latest",
+    "graphology-generators": "^0.11.2",
+    "graphology-types": "^0.24.7",
+    "graphology-metrics": "^2.1.0",
+    "ngraph.graph": "",
+    "ngraph.louvain": "",
+    "ngraph.coarsen": "",
+    "seedrandom": "^3.0.5",
     "father": "^2.30.0",
     "jest": "^26.6.3",
     "jest-electron": "^0.1.11",

packages/graph/src/louvain.ts

@@ -256,7 +256,7 @@ const louvain = (
         propertiesWeightRemove[index] = allPropertiesWeight[nodeRemove.originIndex];
       })
       // the inertialModularity for **removing** the node i from the origin cluster of node i
-      const removeInertialModularity = getInertialModularity(selfClusterNodesAfterRemove, allPropertiesWeight) * inertialWeight;
+      const removeInertialModularity = inertialModularity ? getInertialModularity(selfClusterNodesAfterRemove, allPropertiesWeight) * inertialWeight : 0;
 
       // the neightbors of the node
       const nodeNeighborIds = neighbors[node.id];
@@ -288,7 +288,7 @@ const louvain = (
           propertiesWeightAdd[index] = allPropertiesWeight[nodeAdd.originIndex];
         })
         // the inertialModularity for **adding** node i into this neighbor cluster
-        const addInertialModularity = getInertialModularity(clusterNodesAfterAdd, allPropertiesWeight) * inertialWeight;
+        const addInertialModularity = inertialModularity ? getInertialModularity(clusterNodesAfterAdd, allPropertiesWeight) * inertialWeight : 0;
 
         // the increase modurarity is the difference between addModurarity and removeModurarity
         let increase = addModurarity - removeModurarity;