Finds all chains in a graph.
Remarks
A chain is a path of maximum length in which each internal node has degree 2.
The internal nodes on directed chains all have in-degree 1 and out-degree 1.
Other Path-Related Algorithms
@PRODUCT@ supports a number of other algorithms related to paths in a graph:
- Paths – finds all paths between a set of source and a set of target nodes
- Cycle – finds a cycle if one exists
- LongestPath – finds the longest path in the graph
Examples
const result = new Chains({ directed: true }).run(graph)
result.chains.forEach((path) =>
path.edges.forEach((edge) => graph.setStyle(edge, highlightEdgeStyle)),
)// prepare the chain detection algorithm
const algorithm = new Chains()
// run the algorithm
const result = algorithm.run(graph)
// highlight the cycle
for (const edge of result.chains.flatMap((c) => c.edges)) {
graph.setStyle(edge, highlightChainsStyle)
}Type Details
- yFiles module
- view-layout-bridge
See Also
Constructors
Parameters
A map of options to pass to the method.
- directed - boolean
- A value indicating whether the graph is considered directed or not. This option sets the directed property on the created object.
- subgraphNodes - ItemCollection<INode>
- The collection of nodes which define a subset of the graph for the algorithms to work on. This option either sets the value directly or recursively sets properties to the instance of the subgraphNodes property on the created object.
- subgraphEdges - ItemCollection<IEdge>
- The collection of edges which define a subset of the graph for the algorithms to work on. This option either sets the value directly or recursively sets properties to the instance of the subgraphEdges property on the created object.
Properties
Gets or sets the collection of edges which define a subset of the graph for the algorithms to work on.
Remarks
If nothing is set, all edges of the graph will be processed.
If only the excludes are set, all edges in the graph except those provided in the excludes are processed.
Note that edges which start or end at nodes which are not in the subgraphNodes are automatically not considered by the algorithm.
ItemCollection<T> instances may be shared among algorithm instances and will be (re-)evaluated upon (re-)execution of the algorithm.
Examples
// prepare the chain detection algorithm
const algorithm = new Chains({
// Ignore edges without target arrow heads
subgraphEdges: {
excludes: (edge: IEdge): boolean =>
edge.style instanceof PolylineEdgeStyle &&
edge.style.targetArrow instanceof Arrow &&
edge.style.targetArrow.type === ArrowType.NONE,
},
})
// run the algorithm
const result = algorithm.run(graph)
// highlight the cycle
for (const edge of result.chains.flatMap((c) => c.edges)) {
graph.setStyle(edge, highlightChainsStyle)
}Gets or sets the collection of nodes which define a subset of the graph for the algorithms to work on.
Remarks
If nothing is set, all nodes of the graph will be processed.
If only the excludes are set, all nodes in the graph except those provided in the excludes are processed.
ItemCollection<T> instances may be shared among algorithm instances and will be (re-)evaluated upon (re-)execution of the algorithm.
Examples
// prepare the chain detection algorithm
const algorithm = new Chains({
subgraphNodes: {
// only consider elliptical nodes in the graph
includes: (node: INode): boolean =>
node.style instanceof ShapeNodeStyle &&
node.style.shape === ShapeNodeShape.ELLIPSE,
// but ignore the first node, regardless of its shape
excludes: graph.nodes.first()!,
},
})
// run the algorithm
const result = algorithm.run(graph)
// highlight the cycle
for (const edge of result.chains.flatMap((c) => c.edges)) {
graph.setStyle(edge, highlightChainsStyle)
}Methods
Finds all chains in a graph.
Complexity
O(|V| + |E|)
Parameters
A map of options to pass to the method.
- graph - IGraph
- The input graph to run the algorithm on.
Returns
- ↪ChainsResult
- A ChainsResult which contains all chains.
Throws
- Exception({ name: 'InvalidOperationError' })
- If the algorithm can't create a valid result due to an invalid graph structure or wrongly configured properties.