散点距离分析

Question

我通过散点算法随机生成了3组点，算法是

M = randi(1000,200);
AP = randi(1000,12);
BS = randi(1000,7);
scatter(M(:,1),M(:,20),21,'b.'); hold on
scatter(AP(:,1),AP(:,9),80,'k*');hold on
scatter(BS(:,1),BS(:,4),'r');hold off

现在，我必须为 AP 设置覆盖区域，并分析 AP 与 M 之间的距离，即在覆盖区域内。谁能帮帮我？

Answer 1

首先提取AP的覆盖区域：

ExtractedM=[M(:,1) M(:,20)];
ExtractedAP=[AP(:,1) AP(:,9)];%Just creating two different matrices for plotted points

%calculating coverage area of AP i.e. bounding box for coordinates of AP
yMax=max(ExtractedAP(:,2));
yMin=min(ExtractedAP(:,2));
xMax=max(ExtractedAP(:,1));
xMin=min(ExtractedAP(:,1));

%Finding the points from M which lie in the coverage area of AP
[positionBoundedPointsMx1,dummy]=find(ExtractedM(:,1)>=xMin & ExtractedM(:,1)<=xMax);
[positionBoundedPointsMx2,dummy]=find(ExtractedM(:,2)>=yMin & ExtractedM(:,2)<=yMax);
positionBoundedPointsMx=intersect(positionBoundedPointsMx1,positionBoundedPointsMx2,'rows');
boundedPointsM=ExtractedM(positionBoundedPointsMx,:);

%Making sure that correct sets of points in M have been extracted
scatter(M(:,1),M(:,20),21,'b.'); hold on
scatter(AP(:,1),AP(:,9),80,'k*');hold on
scatter(BS(:,1),BS(:,4),'r');hold on;
scatter(boundedPointsM(:,1),boundedPointsM(:,2),'ko');

M 中提取的点用黑色圆圈内的蓝点表示。看起来是正确的，因为 M 中的所有点都在 AP 的覆盖范围内。

现在，我不确定您要计算什么。假设您只想计算两点之间的欧几里得距离，因此，我将ExtractedAP 和boundedPointsM 转换为向量并使用pdist2

ExtractedAP_Vec=ExtractedAP(:);  %24x1 vector 
boundedPointsM_Vec=boundedPointsM(:);  %224x1 vector

%calculate distance between each point of 'ExtractedAP_Vec' and every point in 'boundedPointsM_Vec'.
dist_AP_M=pdist2(ExtractedAP_Vec,boundedPointsM_Vec); 

附：绘制散点图并自行验证。我不能在这里发布图片，抱歉。