First Gourava Index Calculator

sum plus product of degrees

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About First Gourava Index Calculator

A first Gourava index calculator computing GO₁(G) = Σ [(dᵢ+dⱼ) + dᵢ·dⱼ]. Kulli (2017). Combines additive (Zagreb-like) and multiplicative (Randić-like) perspectives. GO₁ = M₁ + M₂. Unifies first and second Zagreb. Client-side.

First Gourava Index Calculator Features

  • GO₁(G)
  • (d+d)+d·d
  • M₁+M₂
  • Kulli '17
  • Common graphs
First Gourava GO₁(G) = Σ [(dᵢ+dⱼ) + dᵢ·dⱼ] over edges. Kulli (2017). Beautiful: GO₁ = M₁ + M₂, unifying the two most important Zagreb indices into one. Named after a region in India. Additive + multiplicative in one formula.

How to Use

Select graph:

  • GO₁: First Gourava
  • M₁+M₂: Verify
  • Split: Components

M₁ + M₂ Unification

GO₁ = M₁ + M₂. Instead of studying two indices separately, GO₁ captures both in one number. The additive part (d+d) measures local size, the multiplicative part (d·d) measures local connectivity.

Bounds

GO₁(K_n) = n(n-1)/2·[(2(n-1) + (n-1)²)] = n(n-1)/2·(n-1)(n+1)/... For regular: GO₁ = m·(2d + d²) = m·d·(d+2).

Step-by-Step Instructions

  1. 1Select graph.
  2. 2For each edge: (dᵢ+dⱼ) + dᵢ·dⱼ.
  3. 3Sum all terms.
  4. 4Verify GO₁ = M₁+M₂.
  5. 5Decompose contributions.

First Gourava Index Calculator — Frequently Asked Questions

Why combine sum and product?+

Sum (d+d) captures additive degree info. Product (d·d) captures multiplicative info. Together they give a more complete picture. Like knowing both mean AND variance — more information than either alone.

GO₁ = M₁ + M₂ proof?+

GO₁ = Σ_edges [(dᵢ+dⱼ) + dᵢdⱼ] = Σ(dᵢ+dⱼ) + Σdᵢdⱼ = M₁ + M₂. Direct from linearity of summation. Elegant!

When is GO₁ more useful than M₁ or M₂ alone?+

When both local size AND local connectivity matter. Drug-receptor binding depends on both atom count (additive) and bond density (multiplicative) at binding sites.

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