%网上下载到一些MATLAB画有向线段的函数，由于不能有效地满足在图像上画有向线段，于是自己动 手写了一个，希望对你有用 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %函数的功能是画箭头 %注意事项： %line函数的用法 %example %Img=imread('Lena.bmp'); %p=[100 200]; %v=[100 50] ; % figure(1) %imshow(Img); %hold on; %m_arrow(p,v,'r'); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% function m_arrow(PointStart,PointEnd,color) if nargin < 3 color = 'b'; end m = PointStart(1); n=PointStart(2); k=PointEnd(1); l= PointEnd(2); LineLong=sqrt((n-m)^2+(l-k)^2); dwAngle=atan((l-k)/(n-m+eps)); line(PointStart,PointEnd,'Color',color); %画主线 hold on if m>n %终点在起点的右边 x= floor(n-floor(0.15*LineLong+0.5)*cos(dwAngle+3*pi/4)); y= floor(l-floor(0.15*LineLong+.5)*sin(dwAngle+3*pi/4)); p=[x n]; v=[y l]; line(p,v,'Color',color) hold on %画短线段1 xx=floor(n-0.15*LineLong*cos(dwAngle-3*pi/4)); %画短线段2 yy=floor(l-0.15*LineLong*sin(dwAngle-3*pi/4)); pp=[xx n]; vv=[yy l]; line(pp,vv,'Color',color) end 

if m<=n %终点在起点的左边 x= floor(n-floor(0.15*LineLong+0.5)*cos(dwAngle+pi/4)); %画短线段1 y= floor(l-floor(0.15*LineLong+.5)*sin(dwAngle+pi/4)); p=[x n]; v=[y l]; line(p,v,'Color',color) hold on xx=floor(n-0.15*LineLong*cos(dwAngle-pi/4)); %画短线段2 yy=floor(l-0.15*LineLong*sin(dwAngle-pi/4)); pp=[xx n]; vv=[yy l]; line(pp,vv,'Color',color) end 附结果图片