Huber損失
Huber損失関数の定義は以下の通り。
L δ ( a ) = { 1 2 a 2 for | a | ≤ δ , δ ( | a | − 1 2 δ ) , otherwise. {\displaystyle L_{\delta }(a)={\begin{cases}{\frac {1}{2}}{a^{2}}&{\text{for }}|a|\leq \delta ,\\\delta (|a|-{\frac {1}{2}}\delta ),&{\text{otherwise.}}\end{cases}}}