Partial derivative
Learned in front of the derivative, in the middle of our machine learning it is more common partial derivative,
Direction 导数
Directional derivative is carried out for the following gradient preparation, the gradient is a special directional derivative
in the formula first obtained directions of formula, then each of x and y partial derivative, and finally the result of the calculation into the equation intermediate, so the directional derivative is obtained
gradient
It should be noted that, when solved during the gradient, the gradient itself is rising
