Add 2 Math Algorithms

-   Average (Median).
-   Volumes of various shapes.

Author: PatOnTheBack

maths/average_median.js

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+/*
+    author: PatOnTheBack
+    license: GPL-3.0 or later
+
+    This script will find the average (median) of an array of numbers.
+
+    More about medians:
+        https://en.wikipedia.org/wiki/Median
+*/
+
+"use strict";
+
+function median(nums) {
+    // Find median of a list of numbers.
+    // Sort array
+    var sorted_list = nums.sort(function (a, b) {
+        return a - b
+    });
+    var med;
+    console.log("List of numbers: " + sorted_list);
+
+    // Is number of items in list even?
+    if (sorted_list.length % 2 === 0) {
+        // Find index for first middle value.
+        var mid_index_1 = (sorted_list.length / 2) - 1;
+        // Find index for second middle value.
+        var mid_index_2 = (sorted_list.length / 2);
+        // Find value that corresponds to `mid_index_2`
+        var value_2 = sorted_list.slice(mid_index_2, -1)
+        // Divide middle values by 2 to get average (mean).
+        console.log("2: " + sorted_list[mid_index_2])
+        med = ((sorted_list[mid_index_1]) + value_2[0]) / 2;
+        return med; // Return makes `else:` unnecessary.
+    }
+    // Number of items is odd.
+    var mid_index = (sorted_list.length - 1) / 2;
+    // Middle index is median.
+    med = sorted_list[mid_index];
+    return med;
+}
+
+// Run `median` Function to find average of two lists of numbers.
+console.log("Odd number of numbers:");
+console.log(median([2, 4, 6, 8, 20, 50, 70]));
+console.log("Even number of numbers:");
+console.log(median([2, 4, 6, 8, 20, 50]));

maths/volume.js

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+/*
+    author: PatOnTheBack
+    license: GPL-3.0 or later
+
+    This script will find the volumes of various shapes.
+
+    More about volume:
+        https://en.wikipedia.org/wiki/Volume
+*/
+
+"use strict";
+
+var PI = Math.PI;
+
+function vol_cube(side_length) {
+    // Calculate the volume of a cube.
+    // Cube the side_length.
+    return Math.pow(side_length, 3);
+}
+
+function vol_cuboid(width, height, length) {
+    // Calculate the Volume of a Cuboid."
+    // Multiply lengths together.
+    return width * height * length;
+}
+
+
+function vol_cone(area_of_base, height) {
+    /*
+    Calculate the Volume of a Cone.
+
+    Wikipedia reference: https: //en.wikipedia.org/wiki/Cone
+    volume = (1 / 3) * area_of_base * height
+    */
+    return (1 / 3) * area_of_base * height;
+}
+
+function vol_right_circ_cone(radius, height) {
+    /*
+    Calculate the Volume of a Right Circular Cone.
+
+    Wikipedia reference: https: //en.wikipedia.org/wiki/Cone
+    volume = (1 / 3) * pi * radius ^ 2 * height
+    */
+
+    return (1 / 3) * PI * Math.pow(radius, 2) * height;
+}
+
+
+function vol_prism(area_of_base, height) {
+    /*
+    Calculate the Volume of a Prism.
+
+    V = Bh
+    Wikipedia reference: https: //en.wikipedia.org/wiki/Prism_(geometry)
+    */
+    return area_of_base * height;
+}
+
+
+function vol_pyramid(area_of_base, height) {
+    /*
+    Calculate the Volume of a Prism.
+
+    V = (1 / 3) * Bh
+    Wikipedia reference: https: //en.wikipedia.org/wiki/Pyramid_(geometry)
+    */
+    return (1 / 3) * area_of_base * height;
+}
+
+function vol_sphere(radius) {
+    /*
+    Calculate the Volume of a Sphere.
+
+    V = (4 / 3) * pi * r ^ 3
+    Wikipedia reference: https: //en.wikipedia.org/wiki/Sphere
+    */
+    return (4 / 3) * PI * Math.pow(radius, 3);
+}
+
+function vol_circular_cylinder(radius, height) {
+    /*
+    Calculate the Volume of a Circular Cylinder.
+
+    Wikipedia reference: https: //en.wikipedia.org/wiki/Cylinder
+    volume = pi * radius ^ 2 * height
+    */
+    return PI * Math.pow(radius, 2) * height;
+}
+
+// Log the Results of Various Volume Calculations.
+console.log("VOLUMES:");
+console.log("Cube: " + vol_cube(2)); // = 8
+console.log("Cuboid: " + vol_cuboid(2, 2, 2)); // = 8
+console.log("Cone: " + vol_cone(2, 2)); // ~ = 1.33
+console.log("Right Circular Cone: " + vol_right_circ_cone(2, 2)); // ~ = 8.38
+console.log("Prism: " + vol_prism(2, 2)); // = 4
+console.log("Pyramid: " + vol_pyramid(2, 2)); // ~ = 1.33
+console.log("Sphere: " + vol_sphere(2)); // ~ = 33.5
+console.log("Circular Cylinder: " + vol_circular_cylinder(2, 2)); // ~ = 25.1