绘制内部有孔的多边形

Question

我需要绘制一个矩形多边形，里面有一个矩形孔。我找到了这段代码，但我无法理解如何修改以满足我的要求。

 figure()
 p  = [0 0; 0 1; 1 1; 1 0]; %ccw
 pp = [0 0; 1 0; 1 1; 0 1]; %cw
 ph = p + [1.2 0];
 # add hole
 ph(end+1,:) = nan;
 ph = [ph; (pp-[0.5 0.5])*0.5+[1.7 0.5]];
 po = polygon2patch (ph);
 patch (po(:,1), po(:,2), 'b', 'facecolor', 'c');
 axis image

Answer 1

polygon2patch function certainly seems useful, but maybe for only drawing two rectangles, you could also use just two patch 命令，简单地将内部矩形，即孔，设置为白色前景色，如下所示：

outer = [0 0; 2 0; 2 1; 0 1];
inner = [0.4 0.2; 1.6 0.2; 1.6 0.8; 0.4 0.8];
patch(outer(:, 1), outer(:, 2), 'c');
patch(inner(:, 1), inner(:, 2), 'w');
axis equal;

这将产生这样的输出：

希望对您有所帮助！

绘制内部有孔的多边形

Draw polygon with hole inside

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