Kiwis 🥝

A Pandas-inspired data wrangling toolkit in JavaScript

Installation

npm install kiwis

Getting started

const kw = require('kiwis');
const h2g2Characters = kw.DataFrame([   {     name: 'Marvin',     surname: '',     occupation: 'Paranoid Android'   },   {     name: 'Zaphod',     surname: 'Beeblebrox',     occupation: 'President of the Galaxy'   },   {     name: 'Arthur',     surname: 'Dent',     occupation: null   } ]);
h2g2Characters.show();
/*   |   name |    surname |              occupation ================================================= 0 | Marvin |        N/A |        Paranoid Android 1 | Zaphod | Beeblebrox | President of the Galaxy 2 | Arthur |       Dent |                     N/A
[3 rows × 3 columns] Columns: name, surname, occupation */
console.log(h2g2Characters.get(1));
/* {   name: 'Zaphod',   surname: 'Beeblebrox',   occupation: 'President of the Galaxy' } */
h2g2Characters.name.show();
/* 0 | Marvin 1 | Zaphod 2 | Arthur
Length: 3 */

Documentation

Table of Contents

• Kiwis

- DataFrame - Parameters - Examples - Series - Parameters - Examples - loadCSV - Parameters - Examples - parseCSV - Parameters - Examples - isNA - Parameters - Examples

• DataFrame

- Properties - toArray - clone - get - Parameters - Examples - first - last - find - Parameters - Examples - set - Parameters - Examples - head - Parameters - Examples - tail - Parameters - Examples - slice - Parameters - Examples - rows - Examples - items - Examples - forEach - Parameters - Examples - map - Parameters - Examples - replace - Parameters - Examples - append - Parameters - Examples - insert - Parameters - Examples - concat - Parameters - Examples - join - Parameters - Examples - addColumn - Parameters - Examples - rename - Parameters - Examples - reorder - Parameters - Examples - dropNA - Parameters - Examples - dropDuplicates - Parameters - Examples - filter - Parameters - Examples - drop - Parameters - Examples - sort - Parameters - Examples - shuffle - Parameters - Examples - pivot - Parameters - Examples - toString - show - toCSV - Parameters - Examples - toJSON - Parameters - Examples

• Series

- Properties - toArray - clone - get - Parameters - Examples - first - last - find - Parameters - Examples - set - Parameters - Examples - head - Parameters - Examples - tail - Parameters - Examples - slice - Parameters - Examples - values - Examples - items - Examples - forEach - Parameters - Examples - map - Parameters - Examples - append - Parameters - Examples - insert - Parameters - Examples - concat - Parameters - Examples - dropNA - Parameters - Examples - dropDuplicates - Parameters - Examples - any - Parameters - Examples - all - Parameters - Examples - filter - Parameters - Examples - drop - Parameters - Examples - sort - Parameters - Examples - shuffle - Parameters - Examples - unique - counts - Parameters - Examples - frequencies - Parameters - Examples - round - Parameters - Examples - reduce - Parameters - Examples - sum - min - max - extent - mean - median - std - toString - show - toCSV - Parameters - Examples - toJSON - Parameters - Examples

• PivotTable

- Properties - rollup - Parameters - Examples - count - Examples - sum - Parameters - Examples - min - Parameters - Examples - max - Parameters - Examples - mean - Parameters - Examples - median - Parameters - Examples - std - Parameters - Examples - toString - show - toJSON - Parameters - Examples

Kiwis

DataFrame

Returns a new DataFrame from the given data

Parameters

• data Array<Object> An array of objects

Examples

const kw = require('kiwis');
const df = kw.DataFrame([   {     name: 'Marvin',     surname: '',     occupation: 'Paranoid Android'   },   {     name: 'Zaphod',     surname: 'Beeblebrox',     occupation: 'President of the Galaxy'   },   {     name: 'Arthur',     surname: 'Dent',     occupation: null   } ]);
console.log(df.length) // 3 console.log(df.columns) // ['name', 'surname', 'occupation'] console.log(df.empty) // false

Returns DataFrame

Series

Returns a new Series from the given data

Parameters

• data Array<any> An array of values

Examples

const kw = require('kiwis');
const series = kw.Series([1, 1, 2, 3, 5, 8, 13, 21, 34]);
console.log(series.length) // 9 console.log(series.empty) // false

Returns Series

loadCSV

Loads a CSV file into a DataFrame

Parameters

• path string Path of the file to load
• options Object? Options (optional, default {})

- options.delimiter string Delimiter of the file (optional, default ',') - options.encoding string Encoding of the file (optional, default 'utf8') - options.prettify ("none" \| "camelCase" \| "snake_case") Prettify column names (optional, default 'none')

Examples

const kw = require('kiwis');
// Loads a CSV file const df = kw.loadCSV('myAwesomeData.csv');
// Loads a TSV file and prettify the columns in camelCase const df = kw.loadCSV('myAwesomeData.tsv', { delimiter: '\t', prettify; 'camelCase' });

Returns DataFrame

parseCSV

Parses a CSV string into a DataFrame

Parameters

• csv string CSV string to parse
• options Object? Options (optional, default {})

- options.delimiter string Delimiter of the file (optional, default ',') - options.prettify ("none" \| "camelCase" \| "snake_case") Prettify column names (optional, default 'none')

Examples

const kw = require('kiwis');
// Parses a CSV string const df = kw.parseCSV(   name,surname,occupation\n   Marvin,,Paranoid Android\n   Zaphod,Beeblebrox,President of the Galaxy\n   Arthur,Dent,\n );

Returns DataFrame

isNA

Determines whether a value is N/A or not

Parameters

• value any
• options Object? Options (optional, default {})

- options.keep Array<any> Array of falsy values not considered N/A (optional, default [0,false])

Examples

Kiwis.isNA('kiwi'); // false
Kiwis.isNA(''); // true
Kiwis.isNA('', { keep: [0, false, ''] }); // false

Returns boolean

DataFrame

Properties

• length number The number of rows in the DataFrame
• empty boolean Whether the DataFrame contains any row or not
• columns Array<string> The columns of the DataFrame

toArray

Returns the DataFrame as an array

Returns Array<Object>

clone

Clones the DataFrame

Returns DataFrame

get

Returns any row of the DataFrame

Parameters

• index number

Examples

// Returns the row at index 4
df.get(4);

Returns Object

first

Returns the first row of the DataFrame

Returns Object

last

Returns the last row of the DataFrame

Returns Object

find

Returns a specific row in the DataFrame

Parameters

• condition callback The returned row is the first one that matches this condition

Examples

// Returns the row where the 'name' is 'Marvin'
df.find(row => row.name === 'Marvin');

Returns Object

set

Sets the content of a cell in the DataFrame

Parameters

• index number
• column string
• value any

Examples

// Sets the value for 'name' on the 42nd row to 'Slartibartfast'
df.set(42, 'name', 'Slartibartfast');

head

Returns a new DataFrame containing the first N rows of the DataFrame

Parameters

• n number Number of rows to select (optional, default 5)

Examples

// Returns a new DataFrame with the first 10 rows
df.head(10);

Returns DataFrame

tail

Returns a new DataFrame containing the last N rows of the DataFrame

Parameters

• n number Number of rows to select (optional, default 5)

Examples

// Returns a new DataFrame with the last 5 rows
df.tail();

Returns DataFrame

slice

Returns a new DataFrame with a slice of the original rows

Parameters

• start number Zero-based index at which to start extraction
• end number Zero-based index before which to end extraction (optional, default DataFrame.length)

Examples

// Returns a new DataFrame with rows starting at index 10
df.slice(10);
// Returns a new DataFrame with rows between index 24 (included) and 42 (excluded)
df.slice(24, 42);

Returns DataFrame

rows

Returns the rows of the DataFrame as an iterable

Examples

for (let row of df.rows()) {
  console.log(row);
}

Returns Iterable<Object>

items

Returns an array of index/row pairs as an iterable

Examples

for (let [index, row] of df.items()) {
  console.log(index, row);
}

Returns Iterable<Array<number, Object>>

forEach

Applies a callback function to each row of the DataFrame

Parameters

• callback callback

Examples

// Displays each element in the 'name' column of the DataFrame
df.forEach(row => console.log(row.name));

map

Returns a new Series populated with the results of a callback function applied on each row the DataFrame

Parameters

• callback callback

Examples

// Returns a Series of full names by joining the name and surname for each row of the DataFrame
df.map(row => [row.name, row.surname].join(' '));

Returns Series

replace

Replaces all occurences of the given value in the DataFrame by another value

Parameters

• oldValue any
• newValue any
• options Object? (optional, default {})

- options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false) - options.columns (string \| Array<string>) Columns to replace into (optional, default DataFrame.columns)

Examples

// Replaces all occurrences of 'panda' with 'kiwi' in the column 'animal'
df.replace('panda', 'kiwi', { inPlace: true, columns: 'animal' });

Returns DataFrame

append

Appends new rows to a DataFrame

Parameters

• rows (Object \| Array<Object>) Row or array of rows to append to the DataFrame
• options Object? (optional, default {})

- options.extend boolean Adds new columns to the DataFrame if they do not already exist (optional, default false)

Examples

const rows = [
  {
    name: 'Marvin',
    occupation: 'Robot'
  },
  {
    name: 'Zaphod Beeblebrox',
    occupation: 'President of the Galaxy'
  }
];
df.append(rows, { extend: true });

Returns DataFrame

insert

Inserts new rows into a DataFrame

Parameters

• rows (Object \| Array<Object>) Row or array of rows to insert into the DataFrame
• index number Index to insert the rows at (optional, default 0)
• options Object? (optional, default {})

- options.extend boolean Adds new columns to the DataFrame if they do not already exist (optional, default false)

Examples

// Inserts a new row at index 2 in the DataFrame
df.insert({ name: 'Trillian', species: 'human' }, 2, { extend: true });

Returns DataFrame

concat

Concatenates another DataFrame to the DataFrame

Parameters

• other DataFrame
• options Object? (optional, default {})

- options.extend boolean Adds new columns to the DataFrame if they do not already exist (optional, default false) - options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Concatenates df1 and df2, adding columns from df2 into df1 if they do not exist
df1.concat(df2, { inPlace: true, extend: true });

Returns DataFrame

join

Performs a join of two DataFrames on a given column

Parameters

• other DataFrame
• column string Column to join the DataFrames on
• options Object? (optional, default {})

- options.how ("inner" \| "outer" \| "left" \| "right") How the DataFrames should be joined: 'inner' only keeps the intersection of the rows, 'outer' keeps the union of the rows, 'left' only keeps rows from the current DataFrame, and 'right' only keeps rows from the other DataFrame (optional, default 'inner') - options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Joins DataFrames df1 and df2 along their column 'id', keeping only the rows from df1
df1.join(df2, 'id', { inPlace: true, how: 'left' });

Returns DataFrame

addColumn

Adds a new column to the DataFrame

Parameters

• name string Name of the new column
• column (any | Array<any> | Series) Content of the new column as an array, a Series or any value (to be set on every rows)
• options Object? (optional, default {})

- options.extend boolean If the new column is not the same length as the DataFrame, extends the DataFrame (optional, default false) - options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Adds a new column 'fullName' by applying a function on the DataFrame
df.addColumn(
  'fullName',
  df.map(row => [row.name, row.surname].join(' ')),
  { inPlace: true }
);
// Adds a new column 'species', with 'human' on every rows df.addColumn('species', 'human', { inPlace: true });

Returns DataFrame

rename

Rename columns of the DataFrame

Parameters

• map Object<key, string> Map of the columns to rename to their new names
• options Object? (optional, default {})

- options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Renames column 'occupation' into 'job'
df.rename({ occupation: 'job' }, { inPlace: true });

Returns DataFrame

reorder

Reorder the columns of the DataFrame

Parameters

• names Array<string> Array containing the new order of the columns
• options Object? (optional, default {})

- options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

console.log(df.columns) // ['occupation', 'species', 'name']
df.reorder(['name', 'occupation', 'species'], { inPlace: true });
console.log(df.columns) // ['name', 'occupation', 'species']

Returns DataFrame

dropNA

Drops N/A values from the DataFrame

Parameters

• options Object? (optional, default {})

- options.axis ("rows" \| "columns") Determines whether rows or columns should be dropped (optional, default 'rows') - options.keep Array<any> Array of falsy values to keep in the DataFrame (optional, default [0,false]) - options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Drops all rows containg N/A values
df.dropNA({ inPlace: true });
// Drops all columns containing N/A values (but keeps empty strings as well as 0 and false)
df.dropNA({ axis: 'columns', keep: [0, false, ''], inPlace: true });

Returns DataFrame

dropDuplicates

Drops duplicate rows from the DataFrame

Parameters

• options Object? (optional, default {})

- options.columns (string \| Array<string>) Column or array of columns to consider for comparison (optional, default DataFrame.columns) - options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Drops duplicate rows with similar values for 'name'
df.dropDuplicates({ columns: 'name', inPlace: true });

Returns DataFrame

filter

Filters columns or rows of the DataFrame

Parameters

• filter (callback | Array<string>) Can be a callback (applied to rows or columns) or an array of column names to keep
• options Object? (optional, default {})

- options.axis ("rows" \| "columns") Determines whether the callback should apply to rows or columns (optional, default 'rows') - options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Only keeps the 'date' and 'url' columns
df.filter(['date', 'url'], { inPlace: true });
// Only keeps rows whose date is 4/20/20
df.filter(row => row.date === '2020-04-20', { inPlace: true });
// Only keeps columns whose name contains 'data'
df.filter(column => column.includes('data'), { axis: 'columns', inPlace: true });

Returns DataFrame

drop

Drops columns or rows from the DataFrame

Parameters

• filter (callback | Array<string>) Can be a callback (applied to rows or columns) or an array of column names to drop
• options Object? (optional, default {})

- options.axis ("rows" \| "columns") Determines whether the callback should apply to rows or columns (optional, default 'rows') - options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Removes the 'date' and 'url' columns
df.drop(['date', 'url'], { inPlace: true });
// Removes all rows whose date is 4/20/20
df.drop(row => row.date === '2020-04-20', { inPlace: true });
// Removes columns whose name contains 'data'
df.drop(column => column.includes('data'), { axis: 'columns', inPlace: true });

Returns DataFrame

sort

Sorts the DataFrame

Parameters

• by (string \| Array<string>) Key or array of keys to sort the DataFrame by
• options Object? (optional, default {})

- options.reverse boolean Sorts the DataFrame in descending order (optional, default false) - options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Sorts the DataFrame alphabetically by 'name'
df.sort('name', { inPlace: true });
// Sorts the DataFrame in descending ordr by 'age'
df.sort('age', { reverse: true, inPlace: true });

Returns DataFrame

shuffle

Shuffles the rows or columns of a DataFrame

Parameters

• options Object? (optional, default {})

- options.axis ("rows" \| "columns") Determines whether rows or columns should be shuffled (optional, default 'rows') - options.inPlace boolean Changes the current DataFrame instead of returning a new one (optional, default false)

Examples

// Shuffles the columns of the DataFrame
df.shuffle({ axis: 'columns', inPlace: true });

Returns DataFrame

pivot

Returns a PivotTable along the given columns

Parameters

• columns (string \| Array<string>) Column or array of columns to pivot along

Examples

// Returns a PivotTable along columns 'sector' and 'date'
df.pivot(['sector', 'date']);

Returns PivotTable

toString

Formats the DataFrame for display

Returns string

show

Displays the DataFrame

toCSV

Exports the DataFrame as CSV

Parameters

• path string Path of the file to save (optional, default null)
• options Object? (optional, default {})

- options.delimiter string Delimiter to use (optional, default ',')

Examples

df.toCSV('myAwesomeData.csv'); // to CSV
df.toCSV('myAwesomeData.tsv', { delimiter: '\t' }); // to TSV

Returns (string \| undefined) A CSV string if path is not set

toJSON

Exports the DataFrame as JSON

Parameters

• path string Path of the file to save (optional, default null)
• options Object? (optional, default {})

- options.prettify boolean Prettify JSON output (optional, default true)

Examples

df.toJSON('myAwesomeData.json');

Returns (string \| undefined) A JSON string if path is not set

Series

Properties

• length number The number of values in the Series
• empty boolean Whether the Series contains any value or not

toArray

Returns the Series as an array

Returns Array<any>

clone

Clones the Series

Returns Series

get

Returns any row of the Series

Parameters

• index number

Examples

// Returns the value at index 4
series.get(4);

Returns any

first

Returns the first value of the Series

Returns any

last

Returns the last value of the Series

Returns any

find

Returns a specific value in the Series

Parameters

• condition callback The returned value is the first one that matches this condition

Examples

// Returns the value that contains 'fast'
series.find(value => value.includes('fast'));

Returns any

set

Sets a value in the Series

Parameters

• index number
• value any

Examples

// Sets the 42nd value of the Series to 'Slartibartfast'
df.set(42, 'Slartibartfast');

head

Returns a new Series containing the first N values of the Series

Parameters

• n number Number of values to select (optional, default 5)

Examples

// Returns a new Series with the first 10 values
series.head(10);

Returns Series

tail

Returns a new Series containing the last N values of the Series

Parameters

• n number Number of values to select (optional, default 5)

Examples

// Returns a new Series with the last 5 values
series.tail();

Returns Series

slice

Returns a new Series with a slice of the original values

Parameters

• start number Zero-based index at which to start extraction
• end number Zero-based index before which to end extraction (optional, default Series.length)

Examples

// Returns a new Series with values starting at index 10
series.slice(10);
// Returns a new Series with values between index 24 (included) and 42 (excluded)
series.slice(24, 42);

Returns Series

values

Returns the values of the Series as an iterable

Examples

for (let value of series.values()) {
  console.log(value);
}

Returns Iterable<any>

items

Returns an array of index/value pairs as an iterable

Examples

for (let [index, value] of series.items()) {
  console.log(index, value);
}

Returns Iterable<Array<number, any>>

forEach

Applies a callback function to each value of the Series

Parameters

• callback callback

Examples

// Displays each value of the Series
series.forEach(value => console.log(value));

map

Returns a new Series populated with the results of a callback function applied on the Series

Parameters

• callback callback

Examples

// Double each value in the Series
series.map(value => value * 2);

Returns Series

append

Appends new values to a Series

Parameters

• values (Object \| Array<Object>) Value or array of values to append to the Series

Examples

series.append([42, 101]);

Returns Series

insert

Inserts new values into a Series

Parameters

• values (any | Array<any>) Value or array of values to insert into the Series
• index number Index to insert the values at (optional, default 0)

Examples

// Inserts value 42 at index 2 in the Series
series.insert(42, 2);

Returns Series

concat

Concats another Series to the Series

Parameters

• other Series
• options Object? (optional, default {})

- options.inPlace boolean Changes the current Series instead of returning a new one (optional, default false)

Examples

// Concatenates series1 and series2
series1.concat(series2, { inPlace: true });

Returns Series

dropNA

Drops N/A values from the Series

Parameters

• options Object? (optional, default {})

- options.keep Array<any> Array of falsy values to keep in the Series (optional, default [0,false]) - options.inPlace boolean Changes the current Series instead of returning a new one (optional, default false)

Examples

// Drop all N/A values from the Series
series.dropNA({ inPlace: true });
// Drop all N/A values but keep empty strings
series.dropNA({ keep: [''], inPlace: true });

Returns Series

dropDuplicates

Drops duplicate values from the Series

Parameters

• options Object? (optional, default {})

- options.inPlace boolean Changes the current Series instead of returning a new one (optional, default false)

Examples

series.dropDuplicates({ inPlace: true });

Returns Series

any

Returns true if any value of the series satisfies the given condition

Parameters

• condition callback (optional, default !Kiwis.isNA)

Examples

// Returns true if any value is not N/A
series.any();
// Returns true if any value is greater than 42 series.any(value => value > 42);

Returns boolean

all

Returns true if all values of the series satisfy the given condition

Parameters

• condition callback (optional, default !Kiwis.isNA)

Examples

// Returns true if all values are not N/A
series.all();
// Returns true if all values are greater than 42 series.all(value => value > 42);

Returns boolean

filter

Filters values of the Series

Parameters

• filter callback Callback to apply
• options Object? (optional, default {})

- options.inPlace boolean Changes the current Series instead of returning a new one (optional, default false)

Examples

// Only keeps values greater than 42
series.filter(value => value > 42, { inPlace: true });

Returns Series

drop

Drops values from the Series

Parameters

• filter callback Callback to apply
• options Object? (optional, default {})

- options.inPlace boolean Changes the current Series instead of returning a new one (optional, default false)

Examples

// Only drops values greater than 42
series.drop(value => value > 42, { inPlace: true });

Returns Series

sort

Sorts the Series

Parameters

• options Object? (optional, default {})

- options.reverse boolean Sorts the Series in descending order (optional, default false) - options.inPlace boolean Changes the current Series instead of returning a new one (optional, default false)

Examples

// Sorts the Series in descending order
series.sort({ reverse: true, inPlace: true });

Returns Series

shuffle

Shuffles the values of a Series

Parameters

• options Object? (optional, default {})

- options.inPlace boolean Changes the current Series instead of returning a new one (optional, default false)

Examples

series.shuffle({ inPlace: true });

Returns Series

unique

Returns the unique values in the Series as an array

Returns Array<any>

counts

Returns the number of occurrences for each value in the Series

Parameters

• options Object? (optional, default {})

- options.sort boolean Sorts the counts (optional, default true) - options.reverse boolean Sorts the counts in descending order (optional, default true)

Examples

// Returns the number of occurrences for each value in the Series, in ascending order
series.counts({ reverse: false });

Returns Array<\any, [number]> Counts as an array of of value/count pairs

frequencies

Returns the frequency for each value in the Series

Parameters

• options Object? (optional, default {})

- options.sort boolean Sorts the frequencies (optional, default true) - options.reverse boolean Sorts the frequencies in descending order (optional, default true)

Examples

// Returns the frequency for each value in the Series, in ascending order
series.frequencies({ reverse: false });

Returns Array<\any, [number]> Counts as an array of value/frequency pairs

round

Round the values in the Series

Parameters

• digits number Number of digits for rounding (optional, default 0)
• options Object? (optional, default {})

- options.inPlace boolean Changes the current Series instead of returning a new one (optional, default false)

Examples

// Rounds all values in the digits to 2 decimal points
series.round(2, { inPlace: true });
// Truncates all values in the Series series.round(0, { inPlace: true });

Returns Series

reduce

Returns a single reduced value after applying the given callback to the values of the Series

Parameters

• callback callback
• initial any Value to use as the first argument to the first call of the callback (optional, default Series.first())

Examples

// Returns the sum of all values in the Series
series.reduce((acc, value) => acc + value); // Equivalent to series.sum()
// Returns the product of all values in the Series series.reduce((acc, value) => acc * value, 1);

Returns any

sum

Returns the sum of the values in the Series

Returns number

min

Returns the minimum value in the Series

Returns number

max

Returns the maximum value in the Series

Returns number

extent

Returns the extent of the Series

Returns \[number, number]

mean

Returns the mean of the values in the Series

Returns number

median

Returns the median of the values in the Series

Returns number

std

Returns the standard deviation of the values in the Series

Returns number

toString

Formats the Series for display

Returns string

show

Displays the Series

toCSV

Exports the Series as CSV

Parameters

• path string Path of the file to save (optional, default null)
• options Object? (optional, default {})

- options.name string Column name to use (optional, default 'series')

Examples

series.toCSV('myAwesomeData.csv', { name: 'awesome' });

Returns (string \| undefined) A JSON string if path is not set

toJSON

Exports the Series as a JSON file

Parameters

• path string Path of the file to save (optional, default null)
• options Object? (optional, default {})

- options.name string Column name to use (optional, default 'series') - options.prettify boolean Prettify JSON output (optional, default true)

Examples

series.toJSON('myAwesomeData.json', { name: 'awesome' });

Returns (string \| undefined) A JSON string if path is not set

PivotTable

Properties

• length number The number of rows in the PivotTable
• empty boolean Whether the PivotTable contains any row or not
• columns Array<string> The columns of the PivotTable, starting with the pivots

rollup

Applies the given callback function on the leaves of the PivotTable, returning a DataFrame

Parameters

• callback callback
• options Object? (optional, default {})

- options.name string Name to use for the column in the output DataFrame (optional, default 'data')

Examples

// For each leaf, computes the number of rows where 'score' is greater than 3
df.pivot(['sector', 'date']).rollup(
  leaf => leaf.filter(row => row.score > 3).length,
  { name: 'nbHighScores' }
);

Returns DataFrame

count

Counts the number of leaves for each branch of the PivotTable

Examples

df.pivot(['sector', 'date']).count();

Returns DataFrame

sum

Computes the sum of a given column of the PivotTable

Parameters

• column

Examples

// For each leaf, computes the sum of the column 'score'
df.pivot(['sector', 'date']).sum('score');

Returns DataFrame

min

Computes the minimum value of a given column of the PivotTable

Parameters

• column

Examples

// For each leaf, computes the minimum of the column 'score'
df.pivot(['sector', 'date']).min('score');

Returns DataFrame

max

Computes the maximum value of a given column of the PivotTable

Parameters

• column

Examples

// For each leaf, computes the maximum of the column 'score'
df.pivot(['sector', 'date']).max('score');

Returns DataFrame

mean

Computes the mean of a given column of the PivotTable

Parameters

• column

Examples

// For each leaf, computes the mean of the column 'score'
df.pivot(['sector', 'date']).mean('score');

Returns DataFrame

median

Computes the median of a given column of the PivotTable

Parameters

• column

Examples

// For each leaf, computes the median of the column 'score'
df.pivot(['sector', 'date']).median('score');

Returns DataFrame

std

Computes the standard deviation of a given column of the PivotTable

Parameters

• column

Examples

// For each leaf, computes the standard deviation of the column 'score'
df.pivot(['sector', 'date']).std('score');

Returns DataFrame

toString

Formats the PivotTable for display

Returns string

show

Displays the DataFrame

toJSON

Exports the PivotTable as JSON

Parameters

• path string Path of the file to save (optional, default null)
• options Object? (optional, default {})

- options.prettify boolean Prettify JSON output (optional, default true)

Examples

pivotTable.toJSON('myPivotTable.json');

Returns string