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@graphty/graphty-element / session / GraphStatistics

Interface: GraphStatistics ​

Defined in: graphty-element/src/session/types.ts:500

The facts about the graph's shape that a consumer would otherwise compute for itself.

Every field is derived from one snapshot and cached against it, so the first read after a change pays for the walk and every later read in the same revision is free.

Properties ​

components ​

readonly components: ComponentStatistics

Defined in: graphty-element/src/session/types.ts:569

The connected-component shape.

degreeHistogram? ​

readonly optional degreeHistogram?: Histogram

Defined in: graphty-element/src/session/types.ts:553

How the total degree is distributed: the same measure GraphStatistics.degreeRange summarises, binned the way RunResult.histogram bins a count. One bar per degree when there are few distinct degrees, whole-number bands otherwise; the bars' counts add up to GraphStatistics.nodeCount.

session.data.statistics() always fills it in. It is optional only so statistics a caller builds by hand, to pass to recommendLayout or a cost estimate, need not build one.

ts
const histogram = session.data.statistics().degreeHistogram;
// binning "per-value": bins[i].from === bins[i].to, one degree each

degreeRange ​

readonly degreeRange: readonly [number, number]

Defined in: graphty-element/src/session/types.ts:528

The smallest and the largest total degree in the graph; [0, 0] when there are no nodes.

density ​

readonly density: number

Defined in: graphty-element/src/session/types.ts:509

Edges as a fraction of the pairs that could carry one, self-loops excluded from both halves. Zero for a graph with fewer than two nodes.

directedness ​

readonly directedness: "unknown" | "mixed" | "directed" | "undirected"

Defined in: graphty-element/src/session/types.ts:518

Whether the graph is directed, as a fact about the graph rather than a guess per edge.

"unknown" is the honest answer for an empty graph the element was never told about: under data.directed: "auto" nothing has settled the question yet. "mixed" is in the union because a format can report it; the element does not produce it today, because a snapshot carries one flag for the whole graph.

directednessSource ​

readonly directednessSource: DirectionProvenance

Defined in: graphty-element/src/session/types.ts:520

Where GraphStatistics.directedness came from, so a reader can qualify the claim.

edgeCount ​

readonly edgeCount: number

Defined in: graphty-element/src/session/types.ts:504

Edges in the snapshot, self-loops and repeats included.

meanDegree ​

readonly meanDegree: number

Defined in: graphty-element/src/session/types.ts:538

The mean total degree, over the same measure GraphStatistics.degreeRange summarises: both ends of every edge counted, so a self-loop contributes two. Zero for an empty graph.

It is published because the alternative is every consumer deriving it from the edge count, and 2m / n is the undirected reading: on a directed graph it double-counts, and on any graph it disagrees with the range printed beside it the moment self-loops are involved. One number measured from the same vector as the range cannot drift from it.

nodeCount ​

readonly nodeCount: number

Defined in: graphty-element/src/session/types.ts:502

Nodes in the snapshot.

repeatedEdgeCount ​

readonly repeatedEdgeCount: number

Defined in: graphty-element/src/session/types.ts:526

Edges beyond the first between the same pair of endpoints.

selfLoopCount ​

readonly selfLoopCount: number

Defined in: graphty-element/src/session/types.ts:524

Edges whose two endpoints are the same node.

transitivity? ​

readonly optional transitivity?: number

Defined in: graphty-element/src/session/types.ts:567

The share of wedges -- two edges meeting at a node -- whose open ends are also joined, so that the three nodes form a triangle: the global clustering coefficient, read with arc direction ignored. 0 on a graph with no triangles (a tree, a grid, a sparse random graph), near 1 on a ring of cliques.

ESTIMATED from a fixed sample of 4,000 wedges drawn with a fixed seed, so it is the same for the same graph and within about 0.01 of the exact value. A pair of opposite arcs between two nodes counts as two edges, which reads such a graph slightly low.

Optional because the element is not the only thing that builds this struct: a statistics object written by hand has none, and a reader of the field takes its absence as "unknown".

weighted ​

readonly weighted: boolean

Defined in: graphty-element/src/session/types.ts:522

True when any edge carries a weight other than 1.