Distance function | Formula (continuous form) | Formula (discrete form) |
---|---|---|
Bhattacharyya | D B (P,Q)=−L n(B C(P,Q)) | D B (P,Q)=−L n(B C(P,Q)) |
 | , \(BC(P,Q)=\int \sqrt {P(x)Q(x)}dx \) | \(,BC(P,Q)=\sum \sqrt {P(x)Q(x)} \) |
Hellinger | \( D_{H}=\sqrt { 2\int {(P(x)-Q(x))^{2}}dx} \) | \( D_{H}(P,Q)=\sqrt { 2\sum _{k=1}^{d} {(P(x_{k})-Q(x_{k}))^{2}}} \) |
 | \(= 2\sqrt {1-\int \sqrt {P(x)Q(x)}dx} \) | \( = 2\sqrt {1-\sum _{k=1}^{d} \sqrt {P(x_{k})Q(x_{k})}} \) |
Jaccard | - | D Jac =1−S Jac |
 |  | \( S_{Jac} = \frac {\sum _{k=1}^{d}{P(x_{k})\times Q(x_{k})}}{ \sum _{k=1}^{d}{P(x_{k})^{2}} + \sum _{k=1}^{d}{Q(x_{k})^{2}}- \sum _{k=1}^{d}{P(x_{k}).Q(x_{k})}} \) |