Combine Contour Plot and Quiver Plot

Display contour lines and gradient vectors on the same plot.

Plot 10 contours of $$x{e}^{-x^2-y^2}$$ over a grid from -2 to 2 in the x and y directions.

[X,Y] = meshgrid(-2:0.2:2);
Z = X .* exp(-X.^2 - Y.^2);
contour(X,Y,Z,10)

Calculate the 2-D gradient of Z using the gradient function. The gradient function returns U as the gradient in the x-direction and V as the gradient in the y-direction. Display arrows indicating the gradient values using the quiver function.

[U,V] = gradient(Z,0.2,0.2);
hold on
quiver(X,Y,U,V)
hold off