if 循环功能出问题，急，在线等

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if (0<=i<pi/2)
patch('faces',f,'vertices',vt,'FaceVertexCData',hsv(6),'FaceColor','blue');

elseif (pi/2<=i<pi)
patch('faces',f,'vertices',vt,'FaceVertexCData',hsv(6),'FaceColor','yellow');

elseif pi<=i<3*pi/2
patch('faces',f,'vertices',vt,'FaceVertexCData',hsv(6),'FaceColor','pink');

else 3*pi/2<=i<=2*pi
patch('faces',f,'vertices',vt,'FaceVertexCData',hsv(6),'FaceColor','green');
end
我想在不同角度范围内设定不同的颜色，这个循环结果绘制出来怎么全是蓝色的呀？请高人指点，在线等！谢谢啦！