附录 1：直纹曲面和桌脚边缘线图像绘制程序
%canshu
w=2.5;
r=sqrt(100+1)*w;
l=60-w;
d=l/2;
h=53-3;
theta=asin(h/l);
%shengcheng canshu
v=-25:25;
u=25:60;
[u,v]=meshgrid(u,v);
%qumian canshu fangcheng
x=v;
y=sqrt(r^2-v.^2)+(d*cos(theta)+w-sqrt(r^2-v.^2)).
*(u-sqrt(r^2-v.^2))./sqrt(d^2-+w^2+r^2-v.^2-2*(d*
cos(theta)+w)*sqrt(r^2-v.^2)+2*d*w*cos(theta));
z=d*sin(theta)*(u-sqrt(r^2-v.^2))./sqrt(d^2-+w^2+
r^2-v.^2-2*(d*cos(theta)+w)*sqrt(r^2-v.^2)+2*d*
w*cos(theta));
z=-z;
%cemian tuxiang
figure(1);
mesh(x,y,z);
%zhuojiao bianyuanxian
u=60;
v=-25:25;
x=v;
y=sqrt(r^2-v.^2)+(d*cos(theta)+w-sqrt(r^2-v.^2)).
*(u-sqrt(r^2-v.^2))./sqrt(d^2-+w^2+r^2-v.^2-2*(d*
cos(theta)+w)*sqrt(r^2-v.^2)+2*d*w*cos(theta));
z=d*sin(theta)*(u-sqrt(r^2-v.^2))./sqrt(d^2-+w^2+
r^2-v.^2-2*(d*cos(theta)+w)*sqrt(r^2-v.^2)+2*d*
w*cos(theta));
z=-z;
figure(2);
plot3(x,y,z,'LineWidth',2);
grid on;
附录 2：圆形折叠桌的动态变化过程图绘制程序
%canshu
w=2.5;
r=sqrt(100+1)*w;
l=60-w;
d=l/2;
h=53-3;
theta=asin(h/l);
%zhuobian dian zuobiao
xc=-10:10;
xc=xc*w;
yc=sqrt(r^2-xc.^2);
zc=zeros(1,21);
%gangjin dian zuobiao
xg=-10:10;
xg=xg*w;
yg=d*cos(theta)*ones(1,21)+w;
zg=d*sin(theta)*ones(1,21);
%zhuobian dao gangjin de juli:
for i=1:21
dis(i)=norm([xc(i),yc(i),zc(i)]-[xg(i),yg(i),zg(i)]);
end
%kaicang dao banbian de juli:
for i=1:21
margin(i)=60-yc(i)-dis(i);
end
%muban dingdian zuobiao
for i=1:21
k=(margin(i)+dis(i))/dis(i);
xd(i)=xc(i)+k*(xg(i)-xc(i));
yd(i)=yc(i)+k*(yg(i)-yc(i));
zd(i)=zc(i)+k*(zg(i)-zc(i));
end
figure(1); hold on;
plot3(xc,yc,zc,'*','LineWidth',2);
plot3(xg,yg,zg,'r','LineWidth',2);
for i=1:21
line([xc(i),xg(i)],[yc(i),yg(i)],[zc(i),zg(i)],'LineWid
th',2);
line([xd(i),xg(i)],[yd(i),yg(i)],[zd(i),zg(i)],'LineWi
dth',2);
end
figure(1); hold on;
plot3(xc,-yc,zc,'*');
plot3(xg,-yg,zg,'r');
for i=1:21
line([xc(i),xg(i)],[-yc(i),-yg(i)],[zc(i),zg(i)],'LineW
idth',1,'Color',[.2 .2 .2]);
line([xd(i),xg(i)],[-yd(i),-yg(i)],[zd(i),zg(i)],'LineW
idth',1,'Color',[.2 .2 .2]);
end
plot3(xc,yc,zc);plot3(xc,-yc,zc);
line([xc(1),xc(1)],[yc(1),-yc(1)],[zc(1),zc(1)],'Line
Width',2);
line([xc(21),xc(21)],[yc(21),-yc(21)],[zc(21),zc(21)
],'LineWidth',2);
view(3)
[X,Y,Z]=sphere(30);
