www.gusucode.com > graphics 案例源码程序 matlab代码 > graphics/DisplayVelocityPlotOverContourPlotExample.m
%% Combine Contour Plot and Quiver Plot % This example shows how to combine a contour plot and a quiver plot using % the |hold| function. % Copyright 2015 The MathWorks, Inc. %% % 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