comet應該不可以同時繪製多個質點，可以用下面這種方法~

假設有3個質點，質點的軌跡分別存在x1,y1,x2,y2,x3,y3

pausetime=0.01; %設定繪圖速度

head1=line(-5,1,"color","r", "marker",".","markersize",15);%設定質點標記的顏色，大小，線條

head2=line(-5,1,"color","b", "marker",".","markersize",15);

head3=line(-5,1,"color","k", "marker",".","markersize",15);

for i=1:length(x1)

set(head1,"xdata",x1(i),"ydata",y1(i));%設定質點1的運動

set(head2,"xdata",x2(i),"ydata",y2(i));%設定質點2的運動

set(head3,"xdata",x3(i),"ydata",y3(i));%設定質點3的運動

pause(pausetime);

drawnow;

end

這樣就可以畫很多個點的運動了~