Krichevsky–Trofimov estimator

In information theory, given an unknown stationary source π with alphabet A and a sample w from π, the Krichevsky–Trofimov (KT) estimator produces an estimate pi(w) of the probability of each symbol i ∈ A. This estimator is optimal in the sense that it minimizes the worst-case regret asymptotically. For a binary alphabet and a string w with m zeroes and n ones, the KT estimator pi(w) is defined as: p 0 ( w ) = m + 1 / 2 m + n + 1 , p 1 ( w ) = n + 1 / 2 m + n + 1 .

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