Kiwis 🥝

A Pandas-inspired data wrangling toolkit in JavaScript

$3

npm install kiwis

$3

``js
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

$3

#### DataFrame

Returns a new DataFrame from the given data

##### Parameters

- data Array<Object> An array of objects

##### Examples

`javascript
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

`javascript
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

`javascript
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

`javascript
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

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

Returns boolean

$3

#### 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

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

Returns Iterable<Object>

#### items

Returns an array of index/row pairs as an iterable

##### Examples

`javascript
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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
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

`javascript
df.toJSON('myAwesomeData.json');
`

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

$3

#### 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

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

Returns Iterable<any>

#### items

Returns an array of index/value pairs as an iterable

##### Examples

`javascript
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

`javascript
// 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

`javascript
// 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

`javascript
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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
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

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

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

$3

#### 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

`javascript
// 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

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

Returns DataFrame

#### sum

Computes the sum of a given column of the PivotTable

##### Parameters

- column

##### Examples

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
// 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

`javascript
pivotTable.toJSON('myPivotTable.json');
``

Returns string