Connective Eccentricity Index Calculator

degree/eccentricity ratio

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About Connective Eccentricity Index Calculator

A connective eccentricity index calculator computing Cξ(G) = Σ d(v)/ecc(v). Gupta-Singh-Madan (2000). Ratio of degree to eccentricity per vertex. High-degree, low-eccentricity (central hubs) contribute most. Predicts anti-HIV activity. Client-side.

Connective Eccentricity Index Calculator Features

  • Cξ(G)
  • d/ecc
  • Hub quality
  • Anti-HIV
  • Common graphs
Connective eccentricity Cξ(G) = Σ d(v)/ecc(v). Degree over eccentricity: high-degree vertices close to center contribute most. Gupta-Singh-Madan (2000). Opposite of eccentric connectivity (d·ecc). Cξ identifies 'efficient hubs'.

How to Use

Select graph:

  • Cξ: Conn. ecc.
  • d/ecc: Per vertex
  • Hubs: Quality

Cξ vs ECI

ECI = Σ d·ecc (degree × eccentricity). Cξ = Σ d/ecc (degree ÷ eccentricity). ECI rewards peripheral hubs. Cξ rewards central hubs. They give opposing perspectives on vertex importance.

Drug Design

Cξ predicts anti-HIV activity better than many indices. Central, well-connected atoms are drug binding sites. d/ecc captures 'efficiency': high connectivity at short distance from all parts of the molecule.

Step-by-Step Instructions

  1. 1Select graph.
  2. 2For each vertex: d(v)/ecc(v).
  3. 3Sum contributions.
  4. 4Identify efficient hubs.
  5. 5Apply to drug design.

Connective Eccentricity Index Calculator — Frequently Asked Questions

Why d/ecc instead of d·ecc?+

d/ecc rewards vertices that are BOTH high-degree AND central (low eccentricity). d·ecc rewards vertices that are high-degree OR peripheral. Different pharmacological properties correlate with each.

What makes a vertex contribute most to Cξ?+

Maximum d/ecc: high degree (many connections) AND low eccentricity (near center). In K_n: d/(1) = n-1 for all vertices. In star: hub = (n-1)/1 = n-1, leaf = 1/2.

Regular graphs?+

For d-regular: Cξ = Σ d/ecc(v) = d·Σ 1/ecc(v). Depends only on eccentricity distribution. For vertex-transitive: Cξ = n·d/ecc (all equal).

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