
KL divergence measures the difference between two distributions P and Q; it is always non-negative and zero if and only if P equals Q exactly
Image: Robert Simmon, Public domain, via Wikimedia Commons
KL divergence measures the difference between two distributions P and Q; it is always non-negative and zero if and only if P equals Q exactly
Kullback–Leibler divergence
Kullback–Leibler divergence formula: D_KL(P||Q) = ∑_x∈X P(x) log(P(x)/Q(x))
Cross-entropy H(p,q) = -Σ p(x) log q(x) measures how well q approximates p
Cross-entropy H(p,q) = -Σ p(x) log q(x) quantifies approximation quality between distributions p and q
Jensen–Shannon divergence
Jensen-Shannon divergence formula: D_JS(P||Q) = 1/2 * D_KL(P||(M)) + 1/2 * D_KL(Q||(M))
Lyapunov exponents measure: rate of divergence of nearby trajectories in a dynamical system
Lyapunov exponents measure the rate of divergence of nearby trajectories in a dynamical system
Entropy H = -Σ p(x) log₂ p(x) measures average surprise in bits
Entropy H = -Σ p(x) log₂ p(x) quantifies uncertainty in a system
Chebyshev's inequality says: P(|X-μ| ≥ kσ) ≤ 1/k²
Chebyshev's inequality states: P(|X-μ| ≥ kσ) ≤ 1/k²
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