| 1 | # automation lab |
| 2 | |
| 3 | ## Functions |
| 4 | |
| 5 | All functions are exported from `math.js`. |
| 6 | |
| 7 | ```js |
| 8 | const { add, multiply, power, mean, median, standard_deviation } = require("./math"); |
| 9 | ``` |
| 10 | |
| 11 | - `add(a, b)`: returns the sum of `a` and `b`. |
| 12 | ```js |
| 13 | add(2, 3); // 5 |
| 14 | ``` |
| 15 | - `multiply(a, b)`: returns the product of `a` and `b`. |
| 16 | ```js |
| 17 | multiply(4, 5); // 20 |
| 18 | ``` |
| 19 | - `power(base, exponent)`: returns `base` raised to a whole-number `exponent`; throws a `RangeError` if `exponent` is negative. |
| 20 | ```js |
| 21 | power(2, 3); // 8 |
| 22 | ``` |
| 23 | - `mean(numbers)`: returns the average of an array of numbers; throws a `TypeError` if the array is empty. |
| 24 | ```js |
| 25 | mean([1, 2, 3, 4]); // 2.5 |
| 26 | ``` |
| 27 | - `median(numbers)`: returns the middle value (the average of the two middle values when the length is even); throws a `TypeError` if the array is empty. |
| 28 | ```js |
| 29 | median([3, 1, 2]); // 2 |
| 30 | median([1, 2, 3, 4]); // 2.5 |
| 31 | ``` |
| 32 | - `standard_deviation(numbers)`: returns the population standard deviation; throws a `TypeError` if the array is empty. |
| 33 | ```js |
| 34 | standard_deviation([2, 4, 4, 4, 5, 5, 7, 9]); // 2 |
| 35 | ``` |