Add rounding function (#15)

* Minor doc updates

* Add contribution guidelines in readme

* Update typedoc

* Release v1.0.1

* Add rounding function

* n cannot be infinity

* Normalize bug

* Changelog for v1.0.2

* Release v1.0.2

smath/CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## 1.0.2
+
+- Add rounding function
+- `isNumber` cannot be +/- infinity
+- Fix normalization bug when `min = max`
+
 ## 1.0.1
 
 - Fix minor documentation in `SMath`

smath/package.json

@@ -1,6 +1,6 @@
 {
   "name": "smath",
-  "version": "1.0.1",
+  "version": "1.0.2",
   "description": "Small math function library",
   "main": "dist/index.js",
   "types": "types/index.d.ts",

smath/src/Polate.ts

@@ -15,7 +15,7 @@ export abstract class Polate {
      */
     public static normalize(n: number, min: number, max: number): number {
         if (min === max) {
-            return min;
+            return 0;
         }
         return (n - min) / (max - min);
     }

smath/src/SMath.ts

@@ -13,7 +13,7 @@ export abstract class SMath {
      * ```
      */
     public static isNumber(n: any): boolean {
-        return typeof n === 'number';
+        return typeof n === 'number' && n !== Infinity && n !== -Infinity;
     }
     /**
      * Clamp a number within a range.
@@ -51,4 +51,17 @@ export abstract class SMath {
     public static approx(a: number, b: number, epsilon: number = 1e-6): boolean {
         return a - b < epsilon && b - a < epsilon;
     }
+    /**
+     * Round a number to any number of decimal places.
+     * @param n The number to round
+     * @param d The number of places on the right side of the decimal
+     * @returns The rounded number
+     * @example
+     * ```js
+     * const pi = SMath.round(3.1416, 2); // 3.14
+     * ```
+     */
+    public static round(n: number, d: number): number {
+        return Math.round(n * 10 ** d) / (10 ** d);
+    }
 }