深度学习基础 - 梯度垂直于等高线的切线flyfish给定一个标量函数 f ( x , y ) f(x, y) f(x,y),它的梯度(gradient)是一个向量,表示为 ∇ f ( x , y ) \nabla f(x, y) ∇f(x,y),定义为: ∇ f ( x , y ) = ( ∂ f ∂ x , ∂ f ∂ y ) \nabla f(x, y) = \left( \frac{\partial f}{\partial x}, \frac{\partial f}{\partial y} \right) ∇f(x,y)=(∂x∂f,∂