寫一個室內定位演算法的專利需要畫散點圖，於是畫了一個散點圖，記錄一下。

x1=[25,33,18,19,19.5,21,13];
y1=[89,86,72,88,63,68,79];
x2=[88,71,74,79,83,80,84];
y2=[6,13,9,21,4,7,21];
x3=[21.2,79.8];
y3=[77.8,11.6];
x5=[37];
y5=[77];
plot(x1,y1,'^k','markerface','k','markersize',2);
hold on;
plot(x2,y2,'sk','markerface','k','markersize',2);
hold on;
plot(x3,y3,'xk','markerface','k','markersize',2);
hold on;
plot(x5,y5,'*k','markerface','k','markersize',2);
grid on

legend('分類簇C1','分類簇C2','簇中心點','待定位點');
xlabel('Signal strength of r1')
ylabel('Signal strength of r2')
 

效果圖