List (Array)

Mean (Average Calculation)

You can calculate the mean of a list. Supported mean types are arithmetic, geometric, harmonic and rms (root mean square). By default arithmetic is selected.

import { mean } from "quark-dsa";
 
let list = [2, 6, 4, 5, 8];
mean(list); // returns 5
mean(list, "geometric"); // returns 4.54
mean(list, "harmonic"); // returns 4.03
mean(list, "rms"); // returns 5.39

Median

You can calculate middle value of the list, which is median. If list has even number of items, it will return average of middle two values, otherwise it will return middle value. List will get sorted in ascending order before median calculation.

import { median } from "quark-dsa";
 
let list = [4, 12, 14, 17, 22, 23, 23, 24, 25, 29, 40, 67, 77, 82, 92];
median(list); // returns 24
let list2 = [142, 140, 130, 150, 160, 135, 158, 132];
median(list2); // returns 141

Mode

You can also get the element having highest frequency in the list, which is mode. If the list has only one mode, then it will return as a number. If the list has more than one modes, then it will return all mode values in an array.

import { mode } from "quark-dsa";
 
let list = [3, 3, 6, 9, 16, 16, 16, 27, 27, 37, 48];
mode(list); // returns 16
let list2 = [3, 3, 3, 9, 16, 16, 16, 27, 37, 48];
mode(list2); // returns [3, 16]

Variance

You can calculate the Variance of the list. Variance estimates how far a set of numbers are spread out from its mean value.

import { variance } from "quark-dsa";
 
let list = [46, 69, 32, 60, 52, 41];
variance(list); // returns 177.2
let list2 = [4, 2, 5, 8, 6];
variance(list2); // returns 5

Standard Deviation

Standard Deviation is the square of the variance of the list.

import { standardDeviation } from "quark-dsa";
 
  let list = [46, 69, 32, 60, 52, 41];
  standardDeviation(list); // returns 13.31
  let list2 = [4, 2, 5, 8, 6];
  standardDeviation(list2); // returns 2.24

Remove duplicates

You can remove duplicates from a list and returns the same list. Here, in place operation is performed on the list. Only numbers and strings are supported in the list.

import { removeDuplicates } from "quark-dsa";
 
let list = [1, 2, 3, 3, 2, 1, 4, 5, 1, 5, 8, 3];
removeDuplicates(list); // returns [1, 2, 3, 4, 5, 8];
let list2 = [
  "John",
  "George",
  "Paul",
  "Ringo",
  "George",
  "Bob",
  "Elvis",
  "Freddie",
  "Paul",
];
removeDuplicates(list2); // returns ["John", "George", "Paul", "Ringo", "Bob","Elvis", "Freddie"]

Introduction Number