matlab给定点生成多边形，多边形掩膜处理

例子 help convexHull

x = rand(10,1)

y = rand(10,1)

dt = delaunayTriangulation(x,y)

k = convexHull(dt)

plot(dt.Points(:,1),dt.Points(:,2), '.', 'markersize',10); hold on;

plot(dt.Points(k,1),dt.Points(k,2), 'r'); hold off;

x = [STA(:,1);STA(:,3)];

y =[STA(:,2);STA(:,4)];

dt = delaunayTriangulation(x,y);

k = convexHull(dt)

plot(dt.Points(:,1),dt.Points(:,2), '.', 'markersize',10); hold on;

plot(dt.Points(k,1),dt.Points(k,2), 'r'); hold off;

dt.Points(k,1),dt.Points(k,2) 即多边形边界

%% 多边形边界外的不画图，掩膜处理

isin=inpolygon(point_p_lon,point_p_lat,dt.Points(k,1),dt.Points(k,2));

result1(~isin)=NaN;

% pcolor(point_p_lon,point_p_lat,result1);

% load MyColormaps;colormap(mymap);colorbar;shading interp;

contourf(point_p_lon,point_p_lat,result1,10);shading flat

colorbar;

% colormap(flipud(jet));%色标反转

hold on;

load('shengjielat.mat')

load('shengjielon.mat')

plot(shengjielat,shengjielon)

set(gcf, 'PaperPositionMode', 'auto')