drawarrow.asv

能够实现Fisher线性判别

function drawarrow(point1,point2);

% arrowlen=0.2;
cita=pi/12;

x1=point1(1)
y1=point1(2)
x2=point2(1)
y2=point2(2)
ratio=0.1;
% ratio=arrowlen/sqrt((x1-x2)^2+(y1-y2)^2);

hdline=line([x1,x2],[x2,y2],'LineWidth',2,'color',[0.4 0.4 0.7]);
a1x=x2; 
a1y=y2;
a2x=x2+ratio*(cos(cita)*(x1-x2)-sin(cita)*(y1-y2));
a2y=y2+ratio*(cos(cita)*(y1-y2)+sin(cita)*(x1-x2));
a3x=x2+ratio*(cos(cita)*(x1-x2)+sin(cita)*(y1-y2));
a3y=y2+ratio*(cos(cita)*(y1-y2)-sin(cita)*(x1-x2));
hdhead=patch([a1x a2x a3x],[a1y a2y a3y],'b');