layout |
mathjax |
author |
affiliation |
e_mail |
date |
title |
chapter |
section |
topic |
definition |
sources |
def_id |
shortcut |
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true |
Joram Soch |
BCCN Berlin |
joram.soch@bccn-berlin.de |
2020-07-27 19:51:00 -0700 |
Cross-entropy |
General Theorems |
Information theory |
Shannon entropy |
Cross-entropy |
authors |
year |
title |
in |
pages |
url |
Wikipedia |
2020 |
Cross entropy |
Wikipedia, the free encyclopedia |
retrieved on 2020-07-28 |
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D85 |
ent-cross |
JoramSoch |
Definition: Let $X$ be a discrete random variable with possible outcomes $\mathcal{X}$ and let $P$ and $Q$ be two probability distributions on $X$ with the probability mass functions $p(x)$ and $q(x)$. Then, the cross-entropy of $Q$ relative to $P$ is defined as
$$ \label{eq:ent-cross}
\mathrm{H}(P,Q) = - \sum_{x \in \mathcal{X}} p(x) \cdot \log_b q(x)
$$
where $b$ is the base of the logarithm specifying in which unit the cross-entropy is determined.