Computes the graph centrality for the nodes of a graph.
Remarks
Graph centrality is defined as the reciprocal of the maximum of all shortest path distances from a node to all other nodes in the graph. Nodes with high graph centrality have short distances to all other nodes in the graph.
Other Centrality Measures
@PRODUCT@ supports a number of other centrality measures:
- ClosenessCentrality – emphasize nodes that have short paths to other nodes in a slightly different way
- DegreeCentrality – emphasizes nodes with many edges
- WeightCentrality – emphasizes nodes with highly-weighted edges
- BetweennessCentrality – emphasizes nodes and edges that are part of many short paths
- EigenvectorCentrality – computes the influence a node has on a network. The centrality value is higher if more nodes are connected to that node
- PageRank – computes page rank values for all nodes based on their attached edges
Examples
const result = new GraphCentrality({
directed: true,
// Use the geometric edge length as weight
weights: (edge) =>
edge.style.renderer
.getPathGeometry(edge, edge.style)
.getPath()!
.getLength(),
}).run(graph)
// add node labels for centrality values
// and adjust node size according to centrality
result.normalizedNodeCentrality.forEach(({ key, value }) => {
const node = key
const centrality = value
graph.addLabel(key, String(value))
graph.setNodeLayout(
node,
new Rect(node.layout.center, new Size(centrality, centrality)),
)
})Type Details
- yFiles module
- view-layout-bridge
See Also
1.Constructors
Parameters
A map of options to pass to the method.
- weights - ItemMapping<IEdge,number>
- A mapping for edge weights. This option either sets the value directly or recursively sets properties to the instance of the weights 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 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 algorithm
const algorithm = new GraphCentrality({
directed: true,
// Use the geometric edge length as weight
weights: (edge) =>
edge.style.renderer
.getPathGeometry(edge, edge.style)
.getPath()!
.getLength(),
// 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)
// add node labels for centrality values
// and adjust node size according to centrality
result.normalizedNodeCentrality.forEach((entry) => {
const node = entry.key
const centrality = entry.value
graph.addLabel(node, `${centrality}`)
graph.setNodeLayout(
node,
new Rect(node.layout.center, new Size(centrality, centrality)),
)
})Gets or sets the collection of nodes which define a subset of the graph for the algorithms to work on.
Remarks
If nothing is set, all nodes of the graph will be processed.
If only the excludes are set, all nodes in the graph except those provided in the excludes are processed.
ItemCollection<T> instances may be shared among algorithm instances and will be (re-)evaluated upon (re-)execution of the algorithm.
Examples
// configure the algorithm
const algorithm = new GraphCentrality({
directed: true,
// Use the geometric edge length as weight
weights: (edge) =>
edge.style.renderer
.getPathGeometry(edge, edge.style)
.getPath()!
.getLength(),
subgraphNodes: {
// only consider elliptical nodes in the graph
includes: (node: INode): boolean =>
node.style instanceof ShapeNodeStyle &&
node.style.shape === ShapeNodeShape.ELLIPSE,
// but ignore the first node, regardless of its shape
excludes: graph.nodes.first()!,
},
})
// run the algorithm
const result = algorithm.run(graph)
// add node labels for centrality values
// and adjust node size according to centrality
result.normalizedNodeCentrality.forEach((entry) => {
const node = entry.key
const centrality = entry.value
graph.addLabel(node, `${centrality}`)
graph.setNodeLayout(
node,
new Rect(node.layout.center, new Size(centrality, centrality)),
)
})Gets or sets a mapping for edge weights.
Remarks
Graph centrality computes shortest paths throughout the graph. Edge weights influence the computed length of those paths and thus the centrality measure. If no weights are provided, all edges have the same uniform weight of 1 and the number of edges is effectively the shortest path length.
Edge weights for graph centrality must be positive.
Methods
Computes the graph centrality for the nodes of a graph.
Complexity
- O(|V|² + |V| ⋅ |E|) for unweighted graphs
- O(|V| ⋅ |E| + |V|² ⋅ log(|V|)) for weighted graphs
Parameters
A map of options to pass to the method.
- graph - IGraph
- The input graph to run the algorithm on.
Returns
- ↪GraphCentralityResult
- A GraphCentralityResult from which the calculated centrality values can be obtained.
Throws
- Exception({ name: 'InvalidOperationError' })
- If the algorithm can't create a valid result due to an invalid graph structure or wrongly configured properties.