Graham's Scan tests

felipernb · Sep 8, 2017 · f991768 · f991768
1 parent bfc6e05
commit f991768
Showing 1 changed file with 78 additions and 0 deletions.
diff --git a/src/test/algorithms/geometry/graham_scan.js b/src/test/algorithms/geometry/graham_scan.js
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+const grahamScan = require('../../../algorithms/geometry/graham_scan');
+const assert = require('assert');
+
+describe('Graham s Scan algorithm', () => {
+  /* we have to ensure the order before using deepEqual. */
+  let pointComparison;
+  before(() => {
+    pointComparison = function(a, b) {
+      return (a.x != b.x) ? a.x < b.x : a.y < b.y;
+    };
+  });
+
+  it('ConvexHull of set 0', () => {
+    const P = [{x: 3, y: 4}, {x: 5, y: 2}, {x: 7, y: 4},
+                {x: 3, y: 5}, {x: 4.7, y: 3.66}, {x: 5.4, y: 4.52},
+                {x: 5, y: 6}, {x: 6, y: 6}, {x: 5.62, y: 3.5}];
+    const convexHullOfP = [{x: 3, y: 4}, {x: 5, y: 2}, {x: 7, y: 4},
+                            {x: 3, y: 5}, {x: 5, y: 6}, {x: 6, y: 6}];
+    convexHullOfP.sort(pointComparison);
+    const computedConvexHull = grahamScan(P);
+    computedConvexHull.sort(pointComparison);
+    assert.deepEqual(computedConvexHull, convexHullOfP);
+  });
+
+  it('ConvexHull of set 1', () => {
+    const P = [{x: 2.8, y: 3.6}, {x: 4.2, y: 3.7}, {x: 3.6, y: 4.3},
+                {x: 2.2, y: 5.2}, {x: 3.6, y: 5.8}, {x: 4.6, y: 5.2},
+                {x: 4.8, y: 4.5}, {x: 5.6, y: 3.4}, {x: 4, y: 3},
+                {x: 3, y: 3.1}, {x: 1.9, y: 2.7}, {x: 1.6, y: 3.7},
+                {x: 2.3, y: 4.2}, {x: 3, y: 2.4}];
+    const convexHullOfP = [{x: 2.2, y: 5.2}, {x: 3.6, y: 5.8},
+                            {x: 4.6, y: 5.2}, {x: 5.6, y: 3.4},
+                            {x: 1.9, y: 2.7}, {x: 1.6, y: 3.7},
+                            {x: 3, y: 2.4}];
+    convexHullOfP.sort(pointComparison);
+    const computedConvexHull = grahamScan(P);
+    computedConvexHull.sort(pointComparison);
+    assert.deepEqual(computedConvexHull, convexHullOfP);
+  });
+
+  it('ConvexHull of set 2', () => {
+    const P = [{x: 1.7, y: 2.4}, {x: 2.8, y: 2}, {x: 1.3, y: 1.6},
+                {x: 2.4, y: 1.4}, {x: 2.4, y: 0.6}, {x: 1.6, y: 0.7},
+                {x: 4, y: 1}, {x: 4.9, y: 1.3}, {x: 3.5, y: 2.1},
+                {x: 3.7, y: 2.8}, {x: 2.6, y: 3.1}, {x: 0.7, y: 2.8},
+                {x: 0.9, y: 1.6}];
+    const convexHullOfP = [{x: 2.4, y: 0.6}, {x: 1.6, y: 0.7},
+                            {x: 4, y: 1}, {x: 4.9, y: 1.3},
+                            {x: 3.7, y: 2.8}, {x: 2.6, y: 3.1},
+                            {x: 0.7, y: 2.8}, {x: 0.9, y: 1.6}];
+    convexHullOfP.sort(pointComparison);
+    const computedConvexHull = grahamScan(P);
+    computedConvexHull.sort(pointComparison);
+    assert.deepEqual(computedConvexHull, convexHullOfP);
+  });
+
+  it('ConvexHull of set 3', () => {
+    const P = [{x: 2, y: 1}, {x: 3, y: 2}, {x: 4, y: 3}, {x: 5, y: 4},
+                {x: 3, y: 3}, {x: 3, y: 4}, {x: 2.4, y: 3.5}, {x: 3.6, y: 3.5},
+                {x: 2, y: 4}, {x: 2, y: 3}, {x: 2, y: 2}];
+    const convexHullOfP = [{x: 2, y: 1}, {x: 5, y: 4}, {x: 2, y: 4}];
+    convexHullOfP.sort(pointComparison);
+    const computedConvexHull = grahamScan(P);
+    computedConvexHull.sort(pointComparison);
+    assert.deepEqual(computedConvexHull, convexHullOfP);
+  });
+
+  it('ConvexHull of set 4', () => {
+    const P = [{x: 2, y: 1}, {x: 3, y: 2}, {x: 4, y: 3}, {x: 4, y: 4},
+                {x: 2, y: 5}, {x: 2, y: 6}, {x: 2, y: 4}, {x: 5, y: 4},
+                {x: 3, y: 5}, {x: 2, y: 3}, {x: 2, y: 2}];
+    const convexHullOfP = [{x: 2, y: 1}, {x: 5, y: 4}, {x: 2, y: 6}];
+    convexHullOfP.sort(pointComparison);
+    const computedConvexHull = grahamScan(P);
+    computedConvexHull.sort(pointComparison);
+    assert.deepEqual(computedConvexHull, convexHullOfP);
+  });
+});