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shannon_entropy(pvec, base=2)

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Compute the Shannon entropy of a probability vector.

The shannon entropy of a probability vector p=[p0,...,pn1]\vec{p} = [p_0, ..., p_{n-1}] is defined as

H(p)=i=0n1pilogb(pi)H(\vec{p}) = \sum_{i=0}^{n-1} p_i \log_b(p_i)

where bb is the log base and (default 2), and 0logb(0)00 \log_b(0) \equiv 0.


  • pvec (array_like) – a probability vector.
  • base (int) – the base of the logarithm [Default: 2].


The Shannon entropy H(pvec).

Return type


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