Win/Loss Chart

Usage

var WinLossChart = require( '@stdlib/plot/sparklines/unicode/win-loss' );

WinLossChart( [data,] [options] )

Returns a chart instance.

var chart = new WinLossChart();

The constructor accepts the following options:

• autoRender: boolean indicating whether to re-render on a change event.
• bufferSize: data buffer size. If provided, data is kept in a first-in first-out (FIFO) buffer which cannot exceed the buffer size. Default: +infinity.
• data: chart data.
• description: chart description.
• isDefined: accessor function indicating whether a datum is defined.
• label: data label.

Writable Properties

WinLossChart.prototype.autoRender

Rendering mode. If true, an instance renders on each 'change' event; otherwise, rendering must be triggered manually.

var chart = new WinLossChart();

// Set:
chart.autoRender = false;

// Get:
var mode = chart.autoRender;
// returns false

WinLossChart.prototype.bufferSize

Data buffer size. If set, this specifies the maximum number of data elements which can be rendered. Once the data buffer is full, each new datum results in the oldest datum being removed.

var chart = new WinLossChart();

// Set:
chart.bufferSize = 3;

// Get:
var size = chart.bufferSize;
// returns 3

chart.data = [ 1, 2, 3 ];

var data = chart.data;
// returns [ 1, 2, 3 ]

chart.push( 4 );

data = chart.data;
// returns [ 2, 3, 4 ]

Setting a data buffer size is useful when rendering data streams.

WinLossChart.prototype.data

Chart data. When set, the value must be either array-like or an ndarray and cannot exceed the bufferSize.

var Int8Array = require( '@stdlib/array/int8' );

var chart = new WinLossChart();

// Set:
chart.data = new Int8Array( [ -2, 1, 2, 2, 1, -1, -1, 1 ] );

// Get:
var data = chart.data;
// returns [ -2, 1, 2, 2, 1, -1, -1, 1 ]

Note that data is copied to an internal data buffer.

WinLossChart.prototype.description

Chart description.

var chart = new WinLossChart();

// Set:
chart.description = 'Wins and losses for the past 30 days.';

// Get:
var desc = chart.description;
// returns 'Wins and losses for the past 30 days.'

WinLossChart.prototype.isDefined( d, i )

An accessor function which defines whether a datum is defined. This accessor is used to define how missing values are encoded. When invoked, the function is provided two arguments:

• d: datum
• i: datum index

function isDefined( d ) {
    // Ignore home losses:
    return ( d !== -2 );
}

var chart = new WinLossChart();

// Set:
chart.isDefined = isDefined;

// Get:
var fcn = chart.isDefined;
// returns <Function>

The default behavior is to ignore any values which are not 1, -1, 2, or -2.

WinLossChart.prototype.label

Data label.

var chart = new WinLossChart();

// Set:
chart.label = 'beep';

// Get:
var label = chart.label;
// returns 'beep'

Methods

WinLossChart.prototype.push( datum )

Appends data to a chart.

var chart = new WinLossChart( [ 1, 2, 3 ] );

var data = chart.data;
// returns [ 1, 2, 3 ]

chart.push( 4 );

data = chart.data;
// returns [ 1, 2, 3, 4 ]

WinLossChart.prototype.render()

Renders a win/loss chart sparkline.

var chart = new WinLossChart( [ -2, 1, 2, 2, 1, -1, -1, 1, -2, -2 ] );

var str = chart.render();
// returns '┌╵└┴╵╷╷╵┌┬'

Glyphs:

If a 2 or -2 is preceded by a 2 or -2,

Based on the win/loss analogy,

• 1: win away
• -1: loss away
• 2: win at home
• -2: loss at home

If provided any value other than 1, -1, 2, or -2, the value is encoded as a missing value.

WinLossChart.prototype.toString()

Serializes a win/loss chart sparkline as a string by calling the render() method.

var chart = new WinLossChart( [ -2, 1, 2, 2, 1, -1, -1, 1, -2, -2 ] );

var str = chart.toString();
// returns '┌╵└┴╵╷╷╵┌┬'

Events

'change'

Emitted whenever a property value changes.

var chart = new WinLossChart();

chart.on( 'change', onChange );

function onChange() {
    console.log( 'A property was updated.' );
}

'render'

Emitted whenever a sparkline is rendered.

var chart = new WinLossChart();

chart.on( 'render', onRender );

function onRender( str ) {
    console.log( 'Rendered sparkline: %s', str );
}