$\mathrm {H} (X)=\mathbb {E} [\log \frac{1}{p(X)}]$
Is Shannon entropy always nonnegative? I have heard it can be negative for some continuous distributions. A counterexample or a proof of nonnegativity would be appreciated.
$\mathrm {H} (X)=\mathbb {E} [\log \frac{1}{p(X)}]$
Is Shannon entropy always nonnegative? I have heard it can be negative for some continuous distributions. A counterexample or a proof of nonnegativity would be appreciated.
It is always nonnegative for discrete distributions. For continuous distributions (then called sometimes differential entropy) it can indeed be negative. You can find a standard proof at the first chapter of Thomas and Cover.