1. Add annotations and logos to the diagram, set the font size of the logo, etc.
%如何在函数图形上加字，做标识
clf;clear
t=0:pi/50:2*pi;%自变量取值
y=sin(t);plot(t,y);
axis([0,2*pi,-1.2,1.2])%设置坐标轴范围
text(pi/2,1.02,'\fontsize{16}\leftarrow\fontname{隶书}在\pi/2\fontname{隶书}处\itsin(t)\fontname{隶书}取极大值')
%内容解释：text（x，y，s）在图中（x，y）处标注内容为s
%字体大小为16磅，隶书，\it斜体字sin（t）
% Content explanation: text (x, y, s) is marked as s at (x, y) in the figure
%The font size is 16 points, official script, \it italic font sin(t)
2. How to draw a simple 3D image
%如何绘制基本的三维图形
t= 0:pi/50:10*pi;
plot3(sin(t),cos(t),t)
grid on
axis square 