Added example and Unit tests for ClampToZero method on p5.Vector.

src/math/p5.Vector.js

@@ -3901,6 +3901,22 @@ p5.Vector = class {
  * @method clampToZero
  * @return {p5.Vector} with components very close to zero replaced with zero.
  * @chainable
+ * @example
+ * <div">
+ * <code>
+ * function setup() {
+ *   // Create a new vector
+ *   let v = createVector(0.0000000000000002220446049250313, 5 );
+ *
+ *   console.log('Before:', v.x , v.y);
+ *
+ *   // Clamp components close to zero to zero
+ *   v.clampToZero();
+ *   console.log('After:', v.x , v.y);
+ *   describe('Round down very small numbers to zero');
+ * }
+ * </code>
+ * </div>
  */
   clampToZero() {
     this.x = this._clampToZero(this.x);

test/unit/math/p5.Vector.js

@@ -1882,5 +1882,48 @@ suite('p5.Vector', function() {
         expect(p5.Vector.equals(a1, a2)).to.be.true;
       });
     });
+
+    suite('p5.Vector.clampToZero()', function() {
+      let v;
+
+      test('should clamp very small positive number to zero', function() {
+        v = new p5.Vector(0.0000000000000002220446049250313, 5);
+        v.clampToZero();
+        expect(v.x).to.equal(0);
+        expect(v.y).to.equal(5);
+      });
+
+      test('should clamp very small negative number to zero', function() {
+        v = new p5.Vector(-0.0000000000000002220446049250313, 5);
+        v.clampToZero();
+        expect(v.x).to.equal(0);
+        expect(v.y).to.equal(5);
+      });
+
+      test('should not clamp regular numbers', function() {
+        v = new p5.Vector(0.01, 5);
+        v.clampToZero();
+        expect(v.x).to.equal(0.01);
+        expect(v.y).to.equal(5);
+      });
+
+      test('should leave zero components unchanged', function() {
+        v = new p5.Vector(0, 0);
+        v.clampToZero();
+        expect(v.x).to.equal(0);
+        expect(v.y).to.equal(0);
+      });
+
+      test('should clamp very small numbers in all components of a 3D vector to zero', function() {
+        v = new p5.Vector(
+          0.0000000000000002220446049250313,
+          -0.0000000000000002220446049250313,
+          0.0000000000000002220446049250313);
+        v.clampToZero();
+        expect(v.x).to.equal(0);
+        expect(v.y).to.equal(0);
+        expect(v.z).to.equal(0);
+      });
+    });
   });
 });