math-helper-functions

Installation

Using npm, npm i math-helper-functions.

Using yarn, yarn add math-helper-functions.

Usage

Using import

import { calcSum } from 'math-helper-functions';

const input = [{ item: 'bookA', count: 3 }, { item: 'bookB', count: 4 }];

const totalBooks = calcSum(input, 'count'); // totalBooks is 7

In a CommonJS environment

const { calcDomain } = require('math-helper-functions');

const input = [
  { item: 'bookA', count: 3 },
  { item: 'bookB', count: 10 },
  { item: 'bookC', count: 1 },
];

const domain = calcDomain(input, 'count'); // domain is [1, 10]

Table of contents

Functions

• calcDistribution
• calcDomain
• calcHistogram
• calcMax
• calcMean
• calcMedian
• calcMin
• calcPercent
• calcQuartiles
• calcSum
• calcWeightedMean
• calcWeightedMedian
• ruleOfThree

Functions

calcDistribution

▸ calcDistribution(array: any[], numOfBins?: number): IDistribution

Calculates the distribution of an arrays values

export

Parameters:

Name	Type	Description
array	any[]	Input array
numOfBins?	number	-

Returns: IDistribution

The distribution

Defined in: modules/distributions.ts:32

---

calcDomain

▸ calcDomain(array: any[], property?: string): [number, number] | [any, any]

Gets the [min, max] value in an array

export

Parameters:

Name	Type	Description
array	any[]	Input array
property?	string	-

Returns: [number, number] | [any, any]

The domain

Defined in: modules/domain.ts:36

---

calcHistogram

▸ calcHistogram(array: any[], numberOfBins?: number, property?: string): number[]

Calculates a histogram from array values

export

Parameters:

Name	Type	Default value	Description
array	any[]	-	Input array
numberOfBins	number	4	-
property?	string	-	-

Returns: number[]

The histogram

Defined in: modules/distributions.ts:118

---

calcMax

▸ calcMax(array: any[], property?: string): number

Gets the max value in an array

export

Parameters:

Name	Type	Description
array	any[]	Input array
property?	string	-

Returns: number

The maximum value in the array

Defined in: modules/domain.ts:12

---

calcMean

▸ calcMean(array: any[], property?: string): number | undefined

Gets the mean value for an array

export

Parameters:

Name	Type	Description
array	any[]	Input array
property?	string	-

Returns: number | undefined

The mean value

Defined in: modules/averages.ts:94

---

calcMedian

▸ calcMedian(array: any[], property?: string): number | undefined

Gets an array median

export

Parameters:

Name	Type	Description
array	any[]	Input array
property?	string	-

Returns: number | undefined

The resulting median

Defined in: modules/averages.ts:14

---

calcMin

▸ calcMin(array: any[], property?: string): number

Gets the min value in an array

export

Parameters:

Name	Type	Description
array	any[]	Input array
property?	string	-

Returns: number

The minimum value in the array

Defined in: modules/domain.ts:24

---

calcPercent

▸ calcPercent(toCalc: number, total: number): number

Calculates the percentage of a value, given a total

export

Parameters:

Name	Type	Description
toCalc	number	Number to get percentage of
total	number	Total

Returns: number

Percentage of the total

Defined in: modules/percentages.ts:22

---

calcQuartiles

▸ calcQuartiles(array: any[], property: string): [number, number, number]

Gets the quartiles of an array

export

Parameters:

Name	Type	Description
array	any[]	Input array
property	string	Property to map by

Returns: [number, number, number]

The quartiles

Defined in: modules/distributions.ts:97

---

calcSum

▸ calcSum(array: any[], property?: string): number

Gets the sum of the values in an array

export

Parameters:

Name	Type	Description
array	any[]	Input array
property?	string	-

Returns: number

The sum

Defined in: modules/operations.ts:12

---

calcWeightedMean

▸ calcWeightedMean(array: any[], valueProperty: string, weightProperty: string): number

Gets the weighted mean for an array

export

Parameters:

Name	Type	Description
array	any[]	Input array
valueProperty	string	Property to use for value
weightProperty	string	Property to use for weight

Returns: number

The weighted mean

Defined in: modules/averages.ts:107

---

calcWeightedMedian

▸ calcWeightedMedian(array: any[], valueProperty: string, weightProperty: string): number

Gets an array weighted median

export

Parameters:

Name	Type	Description
array	any[]	Input array
valueProperty	string	The property to use as value
weightProperty	string	The property to use as weight

Returns: number

The resulting median

Defined in: modules/averages.ts:42

---

ruleOfThree

▸ ruleOfThree(ifThis: number, isThis: number, thenThat: number): number

Performs a simple rule of three

export

Parameters:

Name	Type	Description
ifThis	number	First param
isThis	number	First result
thenThat	number	Second param

Returns: number

Second result

Defined in: modules/percentages.ts:10