From dae97ffb2d5d085b3f60995bd097d88c3b7efee4 Mon Sep 17 00:00:00 2001
From: Karsten Schmidt <k@postspectacular.com>
Date: Sun, 17 Feb 2019 17:21:45 +0000
Subject: [PATCH] feat(adjacency): add bitmatrix edge counting, add/fix toDot()
 impls, add tests

---
 packages/adjacency/src/binary.ts  | 24 ++++++++++++++++-----
 packages/adjacency/src/index.ts   |  2 +-
 packages/adjacency/src/sparse.ts  |  6 ++----
 packages/adjacency/test/binary.ts | 35 +++++++++++++++++++++++++++++++
 packages/adjacency/test/index.ts  |  6 ------
 packages/adjacency/test/sparse.ts | 32 ++++++++++++++++++++++++++++
 6 files changed, 89 insertions(+), 16 deletions(-)
 create mode 100644 packages/adjacency/test/binary.ts
 delete mode 100644 packages/adjacency/test/index.ts
 create mode 100644 packages/adjacency/test/sparse.ts

diff --git a/packages/adjacency/src/binary.ts b/packages/adjacency/src/binary.ts
index 925624fd3c..297b5ee402 100644
--- a/packages/adjacency/src/binary.ts
+++ b/packages/adjacency/src/binary.ts
@@ -25,11 +25,13 @@ export class AdjacencyBitMatrix implements
     }
 
     mat: BitMatrix;
-    undirected: boolean;
+    protected undirected: boolean;
+    protected numE: number;
 
     constructor(n: number, undirected = false) {
         this.mat = new BitMatrix(n);
         this.undirected = undirected;
+        this.numE = 0;
     }
 
     *edges() {
@@ -44,11 +46,11 @@ export class AdjacencyBitMatrix implements
     }
 
     numEdges(): number {
-        throw new Error("Method not implemented.");
+        return this.numE;
     }
 
     numVertices(): number {
-        throw new Error("Method not implemented.");
+        return this.mat.n;
     }
 
     /**
@@ -62,13 +64,13 @@ export class AdjacencyBitMatrix implements
     }
 
     addEdge(from: number, to: number) {
-        this.mat.setAt(to, from, true);
+        !this.mat.setAt(to, from, true) && this.numE++;
         this.undirected && this.mat.setAt(from, to, true);
         return this;
     }
 
     removeEdge(from: number, to: number) {
-        this.mat.setAt(to, from, false);
+        this.mat.setAt(to, from, false) && this.numE--;
         this.undirected && this.mat.setAt(from, to, false);
         return this;
     }
@@ -107,4 +109,16 @@ export class AdjacencyBitMatrix implements
     toString() {
         return this.mat.toString();
     }
+
+    toDot() {
+        const [type, sep] = this.undirected ?
+            ["graph", "--"] :
+            ["digraph", "->"];
+        const res = [`${type} g {`];
+        for (let e of this.edges()) {
+            res.push(`"${e[0]}"${sep}"${e[1]}";`);
+        }
+        res.push(`}`);
+        return res.join("\n");
+    }
 }
diff --git a/packages/adjacency/src/index.ts b/packages/adjacency/src/index.ts
index 74bd87346b..d2c2c80ec7 100644
--- a/packages/adjacency/src/index.ts
+++ b/packages/adjacency/src/index.ts
@@ -1,3 +1,3 @@
 export * from "./api";
-export * from "./adjacency";
 export * from "./binary";
+export * from "./sparse";
diff --git a/packages/adjacency/src/sparse.ts b/packages/adjacency/src/sparse.ts
index 545ff013e2..ec436e0105 100644
--- a/packages/adjacency/src/sparse.ts
+++ b/packages/adjacency/src/sparse.ts
@@ -157,10 +157,8 @@ export class AdjacencyMatrix extends CSR implements
             ["graph", "--"] :
             ["digraph", "->"];
         const res = [`${type} g {`];
-        for (let i = 0; i < this.m; i++) {
-            for (let j of this.nzRowCols(i)) {
-                res.push(`"${j}"${sep}"${i}";`);
-            }
+        for (let e of this.edges()) {
+            res.push(`"${e[0]}"${sep}"${e[1]}";`);
         }
         res.push(`}`);
         return res.join("\n");
diff --git a/packages/adjacency/test/binary.ts b/packages/adjacency/test/binary.ts
new file mode 100644
index 0000000000..4073e650b5
--- /dev/null
+++ b/packages/adjacency/test/binary.ts
@@ -0,0 +1,35 @@
+import { Pair } from "@thi.ng/api";
+import { AdjacencyBitMatrix } from "../src/index";
+import * as assert from "assert";
+
+const edges: Pair<number, number>[] = [
+    [2, 3],
+    [0, 1],
+    [5, 4],
+    [2, 0],
+];
+
+describe("adjacency (bitmatrix)", () => {
+    it("fromEdges, undirected", () => {
+        const m = AdjacencyBitMatrix.fromEdges(6, edges, true);
+        console.log([...m.edges()]);
+        assert.deepEqual(
+            m.mat.data.slice(0, 6),
+            [
+                1610612736,
+                2147483648,
+                2415919104,
+                536870912,
+                67108864,
+                134217728
+            ],
+            "data"
+        );
+        assert.equal(m.numEdges(), 4, "numEdges");
+        assert.deepEqual(
+            [...m.edges()],
+            [[4, 5], [2, 3], [0, 1], [0, 2]],
+            "edges"
+        );
+    });
+});
diff --git a/packages/adjacency/test/index.ts b/packages/adjacency/test/index.ts
deleted file mode 100644
index 9135e42175..0000000000
--- a/packages/adjacency/test/index.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-// import * as assert from "assert";
-// import * as a from "../src/index";
-
-describe("adjacency", () => {
-    it("tests pending");
-});
diff --git a/packages/adjacency/test/sparse.ts b/packages/adjacency/test/sparse.ts
new file mode 100644
index 0000000000..cfa3ee7a9c
--- /dev/null
+++ b/packages/adjacency/test/sparse.ts
@@ -0,0 +1,32 @@
+import { Pair } from "@thi.ng/api";
+import { AdjacencyMatrix } from "../src/index";
+import * as assert from "assert";
+
+const edges: Pair<number, number>[] = [
+    [2, 3],
+    [0, 1],
+    [5, 4],
+    [2, 0],
+];
+
+describe("adjacency (sparse)", () => {
+    it("fromEdges, undirected", () => {
+        const m = AdjacencyMatrix.fromEdges(6, edges, true);
+        assert.deepEqual(
+            m.rows,
+            [0, 2, 3, 5, 6, 7, 8],
+            "rows"
+        );
+        assert.deepEqual(
+            m.cols,
+            [1, 2, 0, 0, 3, 2, 5, 4],
+            "cols"
+        );
+        assert.equal(m.numEdges(), 4, "numEdges");
+        assert.deepEqual(
+            [...m.edges()],
+            [[0, 1], [0, 2], [2, 3], [4, 5]],
+            "edges"
+        );
+    });
+});