c1_2_1.m

该文件主要包括了matlab的一些主要应用例程!对学习matlab很有帮助

%filename:c1_2_1.m
points=[1  0 -1  0  1
        0  1  0 -1  0];
th=0:4;
x=[0 1 0 -1 0 1 0; pi/2 0 1 0 -1 0 pi/2];
circle=spline(th,x);
xx=0:.1:4; 
cc=ppval(circle, xx);
plot(points(1,:),points(2,:),'o','markersize',2*6);
hold on
plot(cc(1,:),cc(2,:),'k-','linewidth',1.5);
axis equal
[breaks,coefs,l,k,d]=unmkpp(circle); 
pt=-1:0.1:1;
ppc=cell(k,1);
flagx=[1;-1;-1;1];
flagy=[1;1;-1;-1];
for i=1:k
   px(i,:)=polyval(coefs(2*i-1,:),pt)+flagx(i)*0.2;
   py(i,:)=polyval(coefs(2*i,:),pt)+flagy(i)*0.2;
   ppc{i,1}=poly2str(coefs(i,:),'t');
   plot(px(i,:),py(i,:),':');
   text(flagx(i),flagy(i),num2str(i));
end
xlabel('\fontsize {12} \bf x \rightarrow');
ylabel('\fontsize {12} \bf y \rightarrow');
hold off