pivot-table-js

A lightweight module that takes an array of objects and produces an array of objects back based on one or more aggregate function per column. Emulating excel pivot tables.

pivot-table-js can calculate different aggregate functions on sets of values. The results can be optionally renamed.

Install

Using npm:

$ npm install pivot-table-js

Using yarn:

$ yarn add pivot-table-js

Example

import { Pivot } from 'pivot-table-js'


const data = [
  {
    domain: 'duckduckgo.com',
    path: '/search',
    traffic: 15000,
    trustFlow: 30
  },
  {
    domain: 'duckduckgo.com',
    path: '/images',
    traffic: 8000,
    trustFlow: 20
  },
  {
    domain: 'google.com',
    path: '/search',
    traffic: 20000,
    trustFlow: 42
  },
  {
    domain: 'google.com',
    path: '/images',
    traffic: 10000,
    trustFlow: 38
  }
]


const index = 'domain'

const aggFunc =   {
  domain: 'count', 
  traffic: ['sum', 'mean'], 
  trustFlow: 'mean' 
}

const rename = ['Domain', 'Frequency', 'Traffic Sum', 'Traffic Average', 'TF Average']

const pivotTable = Pivot(data, index, aggFunc, rename)

console.log(pivotTable)

Will output:

[{
  Domain: 'duckduckgo.com',
  'Frequency': 2,
  'Traffic Sum': 23000,
  'Traffic Average': 11500,
  'TF Average': 25
},
{
  Domain: 'google.com',
  'Frequency': 2,
  'Traffic Sum': 30000,
  'Traffic Average': 15000,
  'TF Average': 40
},
{
  Domain: 'Grand Total',
  'Frequency': 4,
  'Traffic Sum': 53000,
  'Traffic Average': 13250,
  'TF Average': 32.5
}]

Domain	Frequency	Traffic Sum	Traffic Average	Average TF
duckduckgo.com	2	23000	11500	25
google.com	2	30000	15000	40
Grand Total	4	53000	13250	32.5

Updates

New feature allows for multiple funcions on the same column, just enclose the type of funcions in an array

const aggFunc =   {
  domain: 'count', 
  traffic: ['sum', 'mean'], 
  trustFlow: 'mean' 
}

---

Available aggregate functions

Function	Definition
count	Calculates the count of all values in a set
counta	Calculates the count of all values in a set including empty strings
count-unique	Calculates the count of all unique values in a set
sum	Calculates the sum of values.
mean	Calculates the average in a set of values — not rounded
median	Calculates the median in a set of values — not rounded
mode	Calculates the mode in a set of values
min	Minimum gets the minimum value in a set of values
max	Maximun gets the maximum value in a set of values

Usage

Pivot(data, index, values [,rename])

• data <Array<Object>> Prepared Array of objects to pivot against.
• index <string> The index row to use as pivot.
• values <Object> Aggregate functions
  • [column: <string>]: <Array<string>> | string Use array for more than one option on the same column
• rename <Array<string>> Optionally rename the output columns, the order is important.
• returns: <Array<Object>>

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