math-helper-functions

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]

API

Interfaces

IBucket

Defined in: distributions.ts:22

Properties

Property	Type	Defined in
from	number	distributions.ts:24
inside	(val: number) => boolean	distributions.ts:26
label	string	distributions.ts:23
to	number	distributions.ts:25

---

IDistribution

Defined in: distributions.ts:9

Properties

Property	Type	Defined in
data	number[]	distributions.ts:11
labels	string[]	distributions.ts:10

---

IDistributionArrayItem

Defined in: distributions.ts:14

Properties

Property	Type	Defined in
count	number	distributions.ts:16
from	number	distributions.ts:18
label	string	distributions.ts:15
percentage	number	distributions.ts:17
to	number	distributions.ts:19

---

ISerieDistribution

Defined in: distributions.ts:29

Properties

Property	Type	Defined in
data	object[]	distributions.ts:31
labels	string[]	distributions.ts:30

Functions

calcBuckets()

function calcBuckets(
  array: number[],
  strict?: boolean,
  numOfBins?: number,
): IBucket[];

Defined in: distributions.ts:57

Calculate the buckets given a data array and an amount

Parameters

Parameter	Type	Default value	Description
array	number[]	undefined	The data array
strict?	boolean	false	Whether to use real or pretty domain
numOfBins?	number	undefined	Amount of desired buckets

Returns

IBucket[]

The buckets

---

calcDiff()

function calcDiff(array: any[], property?: string): number;

Defined in: domain.ts:47

Gets the absolute difference between the max and min value in an array

Parameters

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

Returns

number

Absolute difference between the max and min of an array

---

calcDistribution()

function calcDistribution(
  array: number[],
  strict: boolean,
  numOfBins?: number,
): IDistribution;

Defined in: distributions.ts:103

Calculates the distribution of an arrays values

Parameters

Parameter	Type	Default value	Description
array	number[]	undefined	Input array
strict	boolean	false
numOfBins?	number	undefined	Number of bins to use

Returns

IDistribution

The distribution

---

calcDistributionAsArray()

function calcDistributionAsArray(
  array: number[],
  binsStrict?: boolean,
  numOfBins?: number,
): IDistributionArrayItem[];

Defined in: distributions.ts:194

Calculates the distribution of an arrays values and outputs an array

Parameters

Parameter	Type	Default value	Description
array	number[]	undefined	Array to calc distribution of
binsStrict?	boolean	false	If false, buckets may be rounded [floor, ceil]
numOfBins?	number	undefined	Number of bins to use

Returns

IDistributionArrayItem[]

The distribution as an array of objects

---

calcDistributionWithSeries()

function calcDistributionWithSeries(
  buckets: IBucket[],
  dataGrouped: Record<string, unknown[]>,
  distributionProp: string,
): ISerieDistribution;

Defined in: distributions.ts:136

Calculates the distribution of an array of grouped objects

Parameters

Parameter	Type	Description
buckets	IBucket[]
dataGrouped	Record<string, unknown[]>
distributionProp	string

Returns

ISerieDistribution

The distribution with labels and data

---

calcDomain()

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

Defined in: domain.ts:33

Gets the [min, max] value in an array

Parameters

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

Returns

[number, number] | [any, any]

The domain

---

calcHistogram()

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

Defined in: distributions.ts:247

Calculates a histogram from array values

Parameters

Parameter	Type	Default value	Description
array	any[]	undefined	Input array
numberOfBins?	number	4	Number of bins to use
property?	string	undefined	Property to map by

Returns

number[]

The histogram

---

calcMax()

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

Defined in: domain.ts:11

Gets the max value in an array

Parameters

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

Returns

number

The maximum value in the array

---

calcMean()

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

Defined in: averages.ts:102

Gets the mean value for an array

Parameters

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

Returns

undefined | number

The mean value

---

calcMedian()

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

Defined in: averages.ts:13

Gets an array median

Parameters

Parameter	Type	Description
array	any[]	Input array
property?	string	The property to map by

Returns

undefined | number

The resulting median

---

calcMin()

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

Defined in: domain.ts:22

Gets the min value in an array

Parameters

Parameter	Type	Description
array	any[]	Input array
property?	string	Property to map

Returns

number

The minimum value in the array

---

calcPercent()

function calcPercent(toCalc: number, total: number): number;

Defined in: percentages.ts:24

Calculates the percentage of a value, given a total

Parameters

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

Returns

number

Percentage of the total

---

calcQuartiles()

function calcQuartiles(
  array: any[],
  property?: string,
): [number, number, number];

Defined in: distributions.ts:224

Gets the quartiles of an array

Parameters

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

Returns

[number, number, number]

The quartiles

---

calcStdDeviation()

function calcStdDeviation<T>(array: T[], property?: string): undefined | number;

Defined in: averages.ts:162

Calculates the standard deviation in an array of numbers

Type Parameters

Type Parameter	Description
T

Parameters

Parameter	Type	Description
array	T[]	Input array
property?	string	Property to use for value

Returns

undefined | number

The standard deviation

---

calcSum()

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

Defined in: operations.ts:11

Gets the sum of the values in an array

Parameters

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

Returns

number

The sum

---

calcVariance()

function calcVariance<T>(array: T[], property?: string): undefined | number;

Defined in: averages.ts:147

Calculates the variance in an array of numbers

Type Parameters

Type Parameter	Description
T

Parameters

Parameter	Type	Description
array	T[]	Input array
property?	string	Property to use for value

Returns

undefined | number

The variance

---

calcWeightedMean()

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

Defined in: averages.ts:114

Gets the weighted mean for an array

Parameters

Parameter	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

---

calcWeightedMedian()

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

Defined in: averages.ts:44

Gets an array weighted median

Parameters

Parameter	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

---

getMinMaxFromBucket()

function getMinMaxFromBucket(bucketLabel: string): number[];

Defined in: distributions.ts:122

Gets the min and max values for a calcDistribution bucket

Parameters

Parameter	Type	Description
bucketLabel	string	The bucket label

Returns

number[]

[min, max]

---

getPercentile()

function getPercentile(
  array: (null | number)[],
  percentile: number,
): undefined | number;

Defined in: percentiles.ts:10

Gets the percentile of an array of values

Parameters

Parameter	Type	Description
array	(null | number)[]	Array to find percentile of
percentile	number	Amount between 0 and 1

Returns

undefined | number

Percentile

---

getUntilPercentageThreshold()

function getUntilPercentageThreshold<T>(
  items: T[],
  accessor: (d: T) => number,
  percentageThreshold: number,
): T[];

Defined in: arrays.ts:57

Gets the top % acc items by an accessor

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
items	T[]	Items to filter
accessor	(d: T) => number	The accessor to get a value to accumulate
percentageThreshold	number	The percentage to stop in (default 80)

Returns

T[]

---

getUntilValueThreshold()

function getUntilValueThreshold<T>(
  items: T[],
  accessor: (d: T) => number,
  threshold: number,
): T[];

Defined in: arrays.ts:28

Gets the top items until a cumulative value threshold

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
items	T[]	Items to filter
accessor	(d: T) => number	The accessor to get a value to accumulate
threshold	number	The absolute threshold to stop in

Returns

T[]

---

ruleOfThree()

function ruleOfThree(ifThis: number, isThis: number, thenThat: number): number;

Defined in: percentages.ts:9

Performs a simple rule of three

Parameters

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

Returns

number

Second result