2楼: Originally posted by zhchh008 at 2014-10-15 21:47:22
clear,clc;
a1=0:1:20;
b1=0:1:20;
r=0:0.5*pi/20:0.5*pi;
x=b1-20;
y=a1-10;
z=13*sin(r)+sqrt(169-(y-13*cos(r)).^2);
%=meshgrid(x,y);
plot3(x,y,z)
% OR scatter3(x,y,z)

3楼: Originally posted by 闵磊子 at 2014-10-16 14:45:06
请问cos后面加点.是为什么啊
...

4楼: Originally posted by Ice0cean at 2014-10-16 20:43:05
点是对向量或矩阵的元素进行操作；
以下是一个小例证；
>> a=;
>> a^2

ans =

     7    10
    15    22

>> a.^2

ans =

     1     4
     9    16...