Finds shortest paths between pairs of multiple sources and sinks.
Remarks
The shortest paths will be determined by invoking a single-source shortest path search for each node in sources. For n sources and m sinks the result thus may contain up to n ⋅ m distinct paths.
Other Shortest Path Algorithms
@PRODUCT@ supports a number of other algorithms that compute shortest paths in a graph:
- ShortestPath – finds the shortest path between two nodes
- SingleSourceShortestPaths – finds shortest paths from a single source node to several other nodes
Other Path-Related Algorithms
@PRODUCT@ also 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
- Chains – finds all chains, that is, sequences of nodes that are each connected with just an edge without branches
- Cycle – finds a cycle if one exists
- LongestPath – finds the longest path in the graph
Examples
// configure the shortest path algorithm
const algorithm = new AllPairsShortestPaths({
// multiple source and sink nodes
sources: sourceNodes,
sinks: targetNodes,
// add edge cost mapping which returns the actual length of the edge
costs: (edge) =>
edge.style.renderer
.getPathGeometry(edge, edge.style)
.getPath()!
.getLength(),
})
// run the algorithm:
// calculate paths from startNode to all nodes in the graph
const result = algorithm.run(graph)
for (const sourceNode of sourceNodes) {
for (const targetNode of targetNodes) {
// and mark the edge path from start to the end node
for (const edge of result.getPathBetween(sourceNode, targetNode)!
.edges) {
graph.setStyle(edge, highlightPathStyle)
}
}
}Type Details
- yFiles module
- view-layout-bridge
Constructors
Parameters
A map of options to pass to the method.
- sources - ItemCollection<INode>
- A collection of source (start) nodes. This option either sets the value directly or recursively sets properties to the instance of the sources property on the created object.
- sinks - ItemCollection<INode>
- A collection of sink (end, target) nodes. This option either sets the value directly or recursively sets properties to the instance of the sinks property on the created object.
- costs - ItemMapping<IEdge,number>
- A mapping for the cost for traversing an edge. This option either sets the value directly or recursively sets properties to the instance of the costs property on the created object.
- directed - boolean
- A value indicating whether edge direction should be considered. 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 a mapping for the cost for traversing an edge.
Remarks
For the shortest path algorithm this is a measure of the edge's length, so more expensive (higher cost) edges are considered longer and avoided if there's a shorter (cheaper) path elsewhere in the graph.
When no costs are provided, uniform costs of 1 are assumed for all edges. This makes a shortest path the path with the fewest edges.
Negative costs are supported only for directed graphs and only if there is no cycle with negative costs. Negative costs are not supported for undirected graphs. run will throw an InvalidOperationError in these cases.
Examples
// setting the cost for traversing e1 and e2 to 1.0
algorithm.costs.mapper.set(e1, 1.0)
algorithm.costs.mapper.set(e2, 1.0)
// all other edges are not set and return 0// returns the length of the actual edge path as cost
algorithm.costs = (edge) =>
edge.style.renderer
.getPathGeometry(edge, edge.style)
.getPath()!
.getLength()Gets or sets a collection of sink (end, target) nodes.
Remarks
Examples
// the sink nodes are provided as collection (the selected nodes)
algorithm = new AllPairsShortestPaths({
sinks: graphComponent.selection.nodes,
})
// the sink nodes are the nodes in the graph for which the delegate returns true
// (nodes in the graph with "sink" as tag)
algorithm = new AllPairsShortestPaths({
sinks: (node) => node.tag === 'sink',
})Gets or sets a collection of source (start) nodes.
Remarks
Examples
// the source nodes are provided as collection (the selected nodes)
algorithm = new AllPairsShortestPaths({
sources: graphComponent.selection.nodes,
})
// the source nodes are the nodes in the graph for which the delegate returns true
// (nodes in the graph with "source" as tag)
algorithm = new AllPairsShortestPaths({
sources: (node) => node.tag === 'source',
})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
// configure the shortest path algorithm
const algorithm = new AllPairsShortestPaths({
// single source - single sink
sources: sourceNodes,
sinks: targetNodes,
// 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 edge path
for (const path of result.paths) {
for (const edge of path.edges) {
graph.setStyle(edge, highlightPathStyle)
}
}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
// configure the shortest path algorithm
const algorithm = new AllPairsShortestPaths({
// single source - single sink
sources: sourceNodes,
sinks: targetNodes,
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 edge path
for (const path of result.paths) {
for (const edge of path.edges) {
graph.setStyle(edge, highlightPathStyle)
}
}algorithm.subgraphNodes = graphComponent.selection.nodesalgorithm.subgraphNodes.excludes = (n) => graph.isGroupNode(n)algorithm.subgraphNodes = graphComponent.selection.nodes
algorithm.subgraphNodes.excludes = (n) => graph.isGroupNode(n)Methods
Finds all shortest paths between pairs of nodes from sources and sinks.
Parameters
A map of options to pass to the method.
- graph - IGraph
- The graph on which the shortest paths are computed.
Returns
Throws
- Exception({ name: 'InvalidOperationError' })
- If the algorithm can't create a valid result due to an invalid graph structure or wrongly configured properties.
Examples
// configure the shortest path algorithm
const algorithm = new AllPairsShortestPaths({
// multiple source and sink nodes
sources: sourceNodes,
sinks: targetNodes,
// add edge cost mapping which returns the actual length of the edge
costs: (edge) =>
edge.style.renderer
.getPathGeometry(edge, edge.style)
.getPath()!
.getLength(),
})
// run the algorithm:
// calculate paths from startNode to all nodes in the graph
const result = algorithm.run(graph)
for (const sourceNode of sourceNodes) {
for (const targetNode of targetNodes) {
// and mark the edge path from start to the end node
for (const edge of result.getPathBetween(sourceNode, targetNode)!
.edges) {
graph.setStyle(edge, highlightPathStyle)
}
}
}