Graphology Layout

Collection of basic layout algorithms to be used with graphology.

Installation

``
npm install graphology-layout
`

Usage

_Basic_

- circular
- random

_Advanced_

- circlePack

_Utilities_

- rotation
- collectLayout
- collectLayoutAsFlatArray
- assignLayout
- assignLayoutAsFlatArray

$3

Arranges the node in a circle (or an sphere/hypersphere in higher dimensions).

_Example_

`js
import {circular} from 'graphology-layout';
// Alternatively, to load only the relevant code:
import circular from 'graphology-layout/circular';

const positions = circular(graph);

// With options:
const positions = circular(graph, {scale: 100});

// To directly assign the positions to the nodes:
circular.assign(graph);

// To pass custom dimensions
const positions = random(graph, {dimensions: ['x1', 'x2']});
`

_Arguments_

- graph _Graph_: target graph.
- options _?object_: options:
- dimensions _?array_ [['x', 'y']]: dimensions of the layout. Cannot work with dimensions != 2.
- center _?number_ [0.5]: center of the layout.
- scale _?number_ [1]: scale of the layout.

$3

Random layout positioning every node by choosing each coordinates uniformly at random on the interval [0, 1).

_Example_

`js
import {random} from 'graphology-layout';
// Alternatively, to load only the relevant code:
import random from 'graphology-layout/random';

const positions = random(graph);

// With options:
const positions = random(graph, {rng: customRngFunction});

// To directly assign the positions to the nodes:
random.assign(graph);

// To pass custom dimensions
const positions = random(graph, {dimensions: ['x', 'y', 'z']});
`

_Arguments_

- graph _Graph_: target graph.
- options _?object_: options:
- dimensions _?array_ [['x', 'y']]: dimensions of the layout.
- center _?number_ [0.5]: center of the layout.
- rng _?function_ [Math.random]: custom RNG function to use.
- scale _?number_ [1]: scale of the layout.

$3

Arranges the nodes as a bubble chart, according to specified attributes.

_Example_

`js
import {circlepack} from 'graphology-layout';
// Alternatively, to load only the relevant code:
import circlepack from 'graphology-layout/circlepack';

const positions = circlepack(graph);

// With options
const positions = circlepack(graph, {
hierarchyAttributes: ['degree', 'community'],
rng: customRngFunction
});

// To directly assign the positions to the nodes:
circlepack.assign(graph);
`

_Arguments_

- graph _Graph_: target graph.
- options _?object_: options:
- attributes _?object_: attributes to map:
- x _?string_ [x]: name of the x position.
- y _?string_ [y]: name of the y position.
- center _?number_ [0]: center of the layout.
- hierarchyAttributes _?list_ [[]]: attributes used to group nodes.
- rng _?function_ [Math.random]: custom RNG function to use.
- scale _?number_ [1]: scale of the layout.

$3

Rotates the node coordinates of the given graph by the given angle in radians (or in degrees using an option).

Note that this function rotates your graph based on its center. If you want to use zero as the center for your rotation, use the centeredOnZero option. This option can also be used as an optimization strategy if you know your graph is already centered on zero to avoid needing to compute the graph's extent.

_Example_

`js
import {rotation} from 'graphology-layout';
// Alternatively, to load only the relevant code:
import rotation from 'graphology-layout/rotation';

const positions = rotation(graph, Math.PI / 2);

// With options:
const positions = rotation(graph, Math.PI / 2, {centeredOnZero: true});

// To directly assign the positions to the nodes:
rotation.assign(graph, Math.PI / 2);
`

_Arguments_

- graph _Graph_: target graph.
- angle _number_: rotation angle in radians (or degrees using an option below).
- options _?object_: options:
- dimensions _?array_ [['x', 'y']]: dimensions to use for the rotation. Cannot work with dimensions != 2.
- degrees _?boolean_ [false]: whether the given angle is in degrees.
- centeredOnZero _?boolean_ [false]: whether to rotate the graph around 0, rather than the graph's center.

$3

Function returning the given graph's layout as {node: {x, y}}.

_Example_

`js
import {collectLayout} from 'graphology-layout/utils';

collectLayout(graph);

// Custom dimensions
collectLayout(graph, {dimensions: ['x', 'y', 'z']});

// Non exhaustive (i.e. node having missing dimensions will be returned also)
collectLayout(graph, {exhaustive: false});
`

_Arguments_

- graph _Graph_: target graph.
- options _?object_: options:
- dimensions _?array_ [['x', 'y']]: array of attribute names for the dimensions.
- exhaustive _?boolean_ [true]: whether to collect positions of nodes having all the dimensions set.

$3

Function returning the given graph's layout as a flat array of length order * dimensions.

_Example_

`js
import {collectLayoutAsFlatArray} from 'graphology-layout/utils';

collectLayoutAsFlatArray(graph);

// Custom dimensions
collectLayoutAsFlatArray(graph, {dimensions: ['x', 'y', 'z']});

// Custom type
collectLayoutAsFlatArray(graph, {type: Float32Array});
`

_Arguments_

- graph _Graph_: target graph.
- options _?object_: options:
- dimensions _?array_ [['x', 'y']]: array of attribute names for the dimensions.
- type _?constructor_ [Float64Array]: array class to use.

$3

Function assigning a {node: {x, y}} layout to the given graph.

_Example_

`js
import {assignLayout} from 'graphology-layout/utils';

assignLayout(graph, layout);

// Custom dimensions
assignLayout(graph, layout, {dimensions: ['x', 'y', 'z']});
`

_Arguments_

- graph _Graph_: target graph.
- layout _object_: layout mapping.
- options _?object_: options:
- dimensions _?array_ [['x', 'y']]: array of attribute names for the dimensions.

$3

Function assigning a flat array layout to the given graph.

_Example_

`js
import {assignLayoutAsFlatArray} from 'graphology-layout/utils';

assignLayoutAsFlatArray(graph, layout);

// Custom dimensions
assignLayoutAsFlatArray(graph, layout, {dimensions: ['x', 'y', 'z']});
`

_Arguments_

- graph _Graph_: target graph.
- layout _array_: layout flat array.
- options _?object_: options:
- dimensions _?array_ [['x', 'y']`]: array of attribute names for the dimensions.