traffic-traversal

Calculate the weights between each vertex node and help you find the fastest route.

import { TrafficGraph, TrafficTraversal } from 'traffic-traversal'

const graph = TrafficGraph.Create()

graph.to('start', {
  b: 10,
  c: 20
}).to('b', { goal: 5 }).to('c', { goal: 5 })

const traversal = TrafficTraversal.Create(graph.state)

traversal.routes('start', 'goal') // ['start', 'b', 'goal']

traversal.traffic('start', 'goal') // 15
traversal.traffic('goal', 'start') // Infinity

traversal.reachable('start', 'goal') // true
traversal.reachable('goal', 'start') // false

traversal.depth('start', 'goal') // 2
traversal.depth('goal', 'start') // Infinity

traversal.distance('start', 'goal') // 2
traversal.distance('goal', 'start') // 2

traversal.edges('start') // ['b', 'c', 'goal']
traversal.edges('start', 1) // ['b', 'c']

Method

TrafficGraph

constructor(data?: TrafficGraphData)

Create a new graph instance. You can generate from existing data using data parameters.

(getter) data: TrafficGraphData

Returns to an array in the form that can serialize the graph information of the current instance.

(getter) state: Readonly<ITrafficGraphState>

The current status of the instance is exported to an immutable object.

(getter) vertices: string[]

Returns all the vertices listed in the current instance in an array.

(getter) clone: TrafficGraph

Currently copied instance and returns to a new instance.

to(source: string, dest: GraphVertex): this

Create a single direction weight route. It is possible to traverse the source to dest, but vice versa is impossible. If you had the same vertex before, the value is overwritten.

You can specify relative values. If you fill in the prior character +=, -=, *=, /=, The target value is calculated based on the current value of the property.

both(a: string, b: GraphVertex): this

Set the weight route that leads to both directions between the two vertices. 'a' vertex and 'b' vertex can traverse to each other.

For example, graph.both('a', { b: 1 }) is same as graph.to('a', { b: 1 }).to('b', { a: 1 })

You can specify relative values. If you fill in the prior character +=, -=, *=, /=, The target value is calculated based on the current value of the property.

all(dest: GraphVertex): this

Set the weight between all vertices passed by parameters.

For example, graph.all({ a: 1, b: 2, c: 3 }) is same as graph.to('a', { b: 2, c: 3 }).to('b', { a: 1, c: 3 }).to('c', { a: 1, b: 2 })

You can specify relative values. If you fill in the prior character +=, -=, *=, /=, The target value is calculated based on the current value of the property.

unlinkTo(source: string, dest: string): this

Delete the single direction weight route created by the to method.

unlinkBoth(a: string, b: string): this

Delete the bidirectional weight route created by the both method.

drop(vertex: string): this

Delete certain vertices. All weight routes connected to the vertex are deleted.

has(vertex: string): boolean

It returns whether the instance has a vertex.

hasAll(...vertices: string[]): boolean

It returns whether all the vertices exist in that instance. Returns false if any of the vertices are missing.

invert(): this

Invert all weights in an instance. For example, when A to B has a 2 weight, it will be -2. It's useful for switching the shortest to longest routes or minimum to maximum traffic in a graph.

TrafficTraversal

constructor(trafficGraphState: ITrafficGraphState)

Create an instance that is responsible for the route and utility functions of the graph instance. It takes a graph.state instance as a parameter.

routes(from: string, to: string): string[]

Finds the route with the lowest weight between two vertices and returns it as an array.

edges(vertex: string, depth = -1): string[]

Returns a list of vertices adjacent to that vertex as an array. You can set a depth limit using the depth parameter.

reachable(from: string, to: string): boolean

Returns whether the target vertex can be reached from the starting vertex.

traffic(from: string, to: string): number

Returns the sum of the least weighted routes from the starting vertex to the target vertex. If unreachable, returns Infinity.

depth(from: string, to: string): number

Returns the shortest distance from the starting vertex to the target vertex. This is similar to the distance method, but takes direction into account. If unreachable, returns Infinity.

distance(a: string, b: string): number

Returns the shortest distance between two vertices. This is similar to the depth method, but does not take direction into account. If unreachable, returns Infinity.

Install

Node.js (cjs)

npm i traffic-traversal

Browser (esm)

<script type="module">
  import { TrafficGraph, TrafficTraversal } from 'https://cdn.jsdelivr.net/npm/[email protected]/dist/esm/index.min.js'
</script>

License

MIT LICENSE