p05416.m

本程序提供三矢量混合积的计算

newplot;clear
axis([-1.5,1.5,-1.5,1.5,0,4.5]);axis('equal');hold on;axis('off')
fline3([0,1.5],[0,0],[0,0],'y');text(0,1.6,0,'Y')
fline3([0,0],[0,1.5],[0,0],'y');text(1.5,-.2,0,'X')
fline3([0,0],[0,0],[0,5.2],'y');text(-.1,0,5.2,'Z')
text(0,-.2,0,'O')
t=0:pi/100:6*pi;
x=cos(t);y=sin(t);z=.25*t;
plot3(x,y,z,'g');z=0*z;plot3(x,y,z,'r');
view(115,20);
x1=cos(pi/2.3);y1=sin(pi/2.3);
plot3([0,x1],[0,y1],[0,0],'c');text(x1,y1,-.2,'N')
plot3([cos(pi/2.3),cos(pi/2.3)],[sin(pi/2.3),sin(pi/2.3)],[0,.25*pi/2.3],'m');
  text(x1,y1-.2,.3*pi/2.5+.1,'M');
t=0:pi/20:pi/2.5;plot3(.2*cos(t),.2*sin(t),0*t,'r')
text(2,-1.5,6.4,' 螺旋线: x=cos(t);y=sin(t);z=t/4','Fontsize',20,'color','green');
hold off;