How i can add the color below the figure?

[Dyuman Joshi]

Draw the x-y plane and color accordingly.

Answer 1

[Star Strider]

If you are referring to the legend in the figure, it would be easiest to use the 'DisplayName' in every surf call so that the descriptions match correctly with the surface being plotted, otherwise you will need to provide the string arguments in the legend call itself.

The legend call should use 'Location','southoutside' with 'NumColumns',3, and 'Interpreter','latex' as its additional arguments. All these are explained in the documentation.

EDIT — (4 Jun 2023 at 14:08)

Simplified Example —

x = linspace(1, 4.5, 50);
y = linspace(-10, 10, 25);
[X,Y] = ndgrid(x, y);
Z1 = X.^5 * 1E+3;
Z2 = X.^3 * 1E+3;

figure
surf(X, Y, Z1, 'FaceColor','b', 'DisplayName','$x^5$')
hold on
surf(X, Y, Z2, 'FaceColor','r', 'DisplayName','$x^3$')
hold off
xlabel('n')
view(140,30)
legend('Location','southoutside', 'NumColumns',2, 'Interpreter','latex')

.