我希望创建一个多边形,使用边缘数据(每个边点的X,Y坐标),这些数据是无序的,我想用一些颜色填充该多边形。
有什么建议吗?
如果你的多边形是凸多边形,你可以使用函数CONVHULL从顶点计算出凸包,并使用绘图函数PATCH绘制多边形。例如:
x = [0 1 0 1]; %# Unordered x coordinates of vertices
y = [0 1 1 0]; %# Corresponding y coordinates of vertices
hullIndices = convhull(x,y); %# Gives vertex indices running counterclockwise
%# around the hull
patch(x(hullIndices),y(hullIndices),'r'); %# Plot the polygon in red
x = [0 1 0 1 0.5]; %# Unordered x coordinates of vertices
y = [0 1 1 0 0.5]; %# Corresponding y coordinates of vertices
edgeLines = [1 3;... %# Point 1 connects to point 3
1 4;... %# Point 1 connects to point 4
2 3;... %# Point 2 connects to point 3
2 5;... %# Point 2 connects to point 5
5 4]; %# Point 5 connects to point 4
dt = DelaunayTri(x(:),y(:),edgeLines); %# Create a constrained triangulation
isInside = inOutStatus(dt); %# Find the indices of inside triangles
faces = dt(isInside,:); %# Get the face indices of the inside triangles
vertices = [x(:) y(:)]; %# Vertex data for polygon
hPolygon = patch('Faces',faces,...
'Vertices',vertices,...
'FaceColor','r'); %# Plot the triangular faces in red
set(hPolygon,'EdgeColor','none'); %# Turn off the edge coloring
xEdge = x(edgeLines).'; %'# Create x coordinates for the edge
yEdge = y(edgeLines).'; %'# Create y coordinates for the edge
hold on; %# Add to the existing plot
line(xEdge,yEdge,'Color','k'); %# Plot the edge in black