Tipify vector-angle

content/snippets/js/s/vector-angle.md

@@ -1,23 +1,24 @@
 ---
-title: Vector angle
-type: snippet
+title: Calculate the angle between two vectors in JavaScript
+shortTitle: Vector angle
+type: tip
 language: javascript
 tags: [math]
 cover: purple-pier
-dateModified: 2021-01-08
+excerpt: Learn how to calculate the angle (theta) between two vectors in JavaScript.
+dateModified: 2024-05-16
 ---
 
-Calculates the angle (theta) between two vectors.
+Given two vectors, you can calculate the angle between them using a few simple math operations. All you need to do is calculate the magnitude of each vector, the scalar product of the two vectors and use the arccosine function to get the **theta** value.
 
-- Use `Array.prototype.reduce()`, `Math.pow()` and `Math.sqrt()` to calculate the magnitude of each vector and the scalar product of the two vectors.
-- Use `Math.acos()` to calculate the arccosine and get the theta value.
+Simply put, you can use `Math.hyptot()` to calculate the **magnitude** of each vector, then multiply the corresponding elements of the two vectors and sum them up. Then, use `Array.prototype.reduce()` to calculate the **scalar product** of the two vectors. Finally, divide the scalar product by the product of the magnitudes of the two vectors and pass the result to `Math.acos()` to get the **angle in radians**.
 
 ```js
-const vectorAngle = (x, y) => {
- let mX = Math.sqrt(x.reduce((acc, n) => acc + Math.pow(n, 2), 0));
- let mY = Math.sqrt(y.reduce((acc, n) => acc + Math.pow(n, 2), 0));
- return Math.acos(x.reduce((acc, n, i) => acc + n * y[i], 0) / (mX * mY));
-};
+const vectorAngle = (x, y) =>
+ Math.acos(
+  x.reduce((acc, n, i) => acc + n * y[i], 0) /
+  (Math.hypot(...x) * Math.hypot(...y))
+ );
 
 vectorAngle([3, 4], [4, 3]); // 0.283794109208328
 ```