Question

[Matlab]用surf命令绘制一个圆环面：

[Matlab]用surf命令绘制一个圆环面：其参数方程如下:

x(u,v)=(R+r*cosv)cosu;
y(u,v)=(R+r*cosv)sinu;
z(u,v)=r*sinv。

其中，

u, v ∈ [0, 2π], R是管子的中心到环面的中心的距离， r是圆管的半径。

Answer 1

surf(X,Y,Z)中，X和Y是方阵，Z是列阵，理解了这个就不难了
function [ ] = surfcircle( )
r=0:0.05:1;theta=0:2*pi/52:2*pi;
nr=length(r);ntheta=length(theta);
X=zeros(nr,ntheta);Y=zeros(nr,ntheta);
nnr=1;
while nnr<=nr
nntheta=1;
while nntheta<ntheta+1
X(nnr,nntheta)=r(nnr)*cos(theta(nntheta));
Y(nnr,nntheta)=r(nnr)*sin(theta(nntheta));
nntheta=nntheta+1;
end
nnr=nnr+1;
end
Z=X*0+Y*0+1;
surf(X,Y,Z);
daspect([1 1 1])
end

Answer 2

x=1:1:12;y=1:1:5;z=[0.20.240.250.260.250.250.250.260.260.290.250.29;0.270.310.30.30.260.280.290.260.260.260.260.29;0.410.410.370.370.380.350.340.350.350.340.350.35;0.410.420.420.410.40.390.390.380.360.360.360.36;0.30.360.40.430.450.450.510.420.40.370.370.37];surf(x,y,z)