Logistic loss
= Logistic loss
For a signed margin $u=yh(x)$, the logistic loss is
$$
\phi(u)=\log(1+e^{-u}).
$$
It is convex and has derivative $\phi'(u)=-e^{-u}/(1+e^{-u})$.
= Logistic loss
For a signed margin $u=yh(x)$, the logistic loss is
$$
\phi(u)=\log(1+e^{-u}).
$$
It is convex and has derivative $\phi'(u)=-e^{-u}/(1+e^{-u})$.