Rényi Entropy & Multifractal Spectrum

Generalized entropies, singularity spectra, and multifractal measures

Rényi Entropy

Rényi entropy Hq generalizes Shannon (q→1), max entropy (q=0), and min-entropy (q→∞). For multifractal measures, the singularity spectrum f(α) — Hausdorff dimension of sets with local Hölder exponent α — encodes the full scaling hierarchy.

H_q = log(Σpᵢq)/(1-q) [q≠1]
H_1 = -Σpᵢlog(pᵢ) (Shannon)
τ(q) = (q-1)D_q
α = dτ/dq, f(α) = qα - τ(q)

Measure Type

Binomial
Cantor
Logistic
Uniform
H₁ (Shannon)
D₀ (Box dim)
D₂ (Corr. dim)
f(α) width Δα