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Self-information

Information theory · Formula · Not yet linked from a lesson

I(x)=−log⁡p(x)I(x) = -\log p(x)

The surprise of one particular outcome. A certain event carries none; a one-in-a- million event carries about twenty bits. Entropy is just this quantity averaged over every outcome.

Symbols

xx
A single outcome.
p(x)p(x)
Its probability.
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