Jensen–Shannon divergence

Information theory · Formula · Not yet linked from a lesson

JSD(P∥Q)=12DKL(P∥M)+12DKL(Q∥M)\mathrm{JSD}(P \parallel Q) = \tfrac{1}{2} D_{\mathrm{KL}}(P \parallel M) + \tfrac{1}{2} D_{\mathrm{KL}}(Q \parallel M)

A symmetric, always-finite cousin of the KL divergence, built by comparing both distributions against their average. Its square root is a true distance, which KL divergence never is.

Symbols

MM
The mixture, equal to half of P plus half of Q.
PP
The first distribution.
QQ
The second distribution.
Esc
↑↓ navigate↵ open? shortcuts

Keyboard shortcuts

Press Esc to close

Anywhere

⌘K
Search and commands
/
Search
?
This sheet
Esc
Close

Reading a lesson

J
Next lesson
K
Previous lesson
B
Bookmark