MATLAB怎么提高循环效率？

乳酸菌

for ppp=1:500:tiaoshu
    tic
    lat0=latRAW(:,ppp);
    lon0=lonRAW(:,ppp);
    dqdt=dqdtRAW(:,ppp);

shuliang=size(dqdt);

for iii=1:(shuliang(1)-1)

if  (dqdt(iii)>=-6.0e-1 && dqdt(iii)<-6.0e-2)
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(5,:),'LineStyle','-','LineWidth',1.0);
elseif (dqdt(iii)>=-6.0e-2 && dqdt(iii)<-6.0e-3) %蓝色17  0 0 1
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(15,:),'LineStyle','-','LineWidth',1.0);
elseif (dqdt(iii)>=-6.0e-3 && dqdt(iii)<-6.0e-4)
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(25,:),'LineStyle','-','LineWidth',1.0);
elseif (dqdt(iii)>=-6.0e-4 && dqdt(iii)<-6.0e-5)
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(35,:),'LineStyle','-','LineWidth',1.0);  
elseif (dqdt(iii)>=-6.0e-5 && dqdt(iii)<-6.0e-6)
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(45,:),'LineStyle','-','LineWidth',1.0);      
elseif (dqdt(iii)>=-6.0e-6 && dqdt(iii)<0.0)%绿色50  0 1 1
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(50,:),'LineStyle','-','LineWidth',1.0);  

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
elseif (dqdt(iii)>=0.0 && dqdt(iii)<6.0e-6)
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(65,:),'LineStyle','-','LineWidth',1.0);
elseif (dqdt(iii)>=6.0e-6 && dqdt(iii)<6.0e-5)
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(75,:),'LineStyle','-','LineWidth',1.0);
elseif (dqdt(iii)>=6.0e-5 && dqdt(iii)<6.0e-4)%黄色83  1 1 0
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(85,:),'LineStyle','-','LineWidth',1.0);
elseif (dqdt(iii)>=6.0e-4 && dqdt(iii)<6.0e-3)
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(95,:),'LineStyle','-','LineWidth',1.0);
elseif (dqdt(iii)>=6.0e-3  && dqdt(iii)<6.0e-2)
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(105,:),'LineStyle','-','LineWidth',1.0);
elseif (dqdt(iii)>=6.0e-2  && dqdt(iii)<6.0e-1)%红色116  1 0 0
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(115,:),'LineStyle','-','LineWidth',1.0);
elseif (dqdt(iii)>=6.0e-1  && dqdt(iii)<=1.0e0)
     linem( [lat0(iii),lat0(iii+1)],[lon0(iii),lon0(iii+1)],'Color',mycolormap(125,:),'LineStyle','-','LineWidth',1.0);  
end

end
hold on
clear iii
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%画空间起点 终点 和 时间中点
linem( lat0(1),lon0(1),'MarkerSize',3,'Marker','o','LineStyle','none','Color',[0 0 0]);
linem( lat0(shuliang(1)),lon0(shuliang(1)),'MarkerSize',3,'Marker','square','LineStyle','none','Color',[0 0 0]);



hold on
toc
clear lat0
clear lon0
clear dqdt
clear shuliang
end
clear ppp
clear lonRAW
clear latRAW
clear dqdtRAW

%%%%%%%%%%%%%%%%%%%%%%%
这样一个循环连点成线的画图，但是我的循环效率会越来越慢，这要怎么解决啊？

Lancelot

判断太多了

天坑一地坑

直接a(a<1) = 0这种，然后把0填色为红色，这样不久好了？