The Loss surface (contours) on the left is for batch gradient descent. Once we have a meshgrid for w, b, we can generate the Loss plot uniquely for a set of training examples given a Loss function…

The Loss surface (contours) on the right is for Stochastic Gradient Descent. As per my understanding, even if I have meshgrid of w and b, I don’t know the loss as it is also dependent on the example chosen. Is my understanding correct?

If yes, how the overall loss plot (contour) *on the right* has been generated (not the dynamcially generated movement of curve that is shown on top of Loss plot but the overall contour plot)