Save points or data in right order

Question

0 个投票

For the below image,the initial plot is as follows

After doing set(gca,'YDir','reverse'); I am able to correct the display to get this

Now what I would like to know is there a way to store the points after reversing the Y Direction

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

sparsh garg 2021-9-1

编辑：Walter Roberson 2021-9-1

在 MATLAB Online 中打开

so I read that we can obtain x and y using h.xData and h.yData

So ,this is what I did

plot(pts(1,:),pts(2,:));
set(gca,'YDir','reverse');
ax=gca;
h = findobj(gca,'Type','line');
x = h.XData; 
y = h.YData;
Final_set_pts=[x;y];

however when I plot final_set_pts,the result is same as before,any suggestions on what i am doing wrong here will be welcome.

请先登录，再进行评论。

请先登录，再回答此问题。

请先登录再关注

Answer 1

Wan Ji 2021-9-1

编辑：Wan Ji 2021-9-1

在 MATLAB Online 中打开

0 个投票

pts.mat

I have answered this question before, now I have a better solution to this problem which can identify many connected regions

clc;clear
load('pts.mat');
pointSet = X_pts;
figure(1)
clf; hold on
scatter(pointSet(:,1),pointSet(:,2),40,'filled','k')
n=1;
while ~isempty(pointSet)
    circleSetInd=1;
    for j=1:length(pointSet)
        disSet=sqrt(sum((pointSet-pointSet(circleSetInd(end),:)).^2,2));
        [~,ind]=sort(disSet);
        ind=ind(1:5);
        [~,~,t_ind]=intersect(circleSetInd,ind);
        ind(t_ind)=[];
        if ~isempty(ind)
            circleSetInd=[circleSetInd;ind(1)];
        else
            n=n+1;
            circleSet{n}=pointSet(circleSetInd,:);
            pointSet(circleSetInd,:)=[];
            break
        end
    end
end
q = cellfun(@isempty,circleSet);
circleSet = circleSet(~q);
for i=1:numel(circleSet)
    plot(circleSet{i}(:,1),circleSet{i}(:,2),'LineWidth',2)
    hold on
end
set(gca,'YDir','reverse');

Or you can set some more connected regions

clc;clear
t = linspace(0,2*pi,101)';
x = 10*cos(t);
y = 10*sin(t).*cos(2*t);
pointSet = [x, y]; % this point set is generated for test
figure(1)
clf; hold on
scatter(pointSet(:,1),pointSet(:,2),40,'filled','k')
n=1;
while ~isempty(pointSet)
    circleSetInd=1;
    for j=1:length(pointSet)
        disSet=sqrt(sum((pointSet-pointSet(circleSetInd(end),:)).^2,2));
        [~,ind]=sort(disSet);
        ind=ind(1:5);
        [~,~,t_ind]=intersect(circleSetInd,ind);
        ind(t_ind)=[];
        if ~isempty(ind)
            circleSetInd=[circleSetInd;ind(1)];
        else
            n=n+1;
            circleSet{n}=pointSet(circleSetInd,:);
            pointSet(circleSetInd,:)=[];
            break
        end
    end
end
q = cellfun(@isempty,circleSet);
circleSet = circleSet(~q);
for i=1:numel(circleSet)
    plot(circleSet{i}(:,1),circleSet{i}(:,2),'LineWidth',2)
    hold on
end
set(gca,'YDir','reverse'); 

2 个评论
显示无隐藏无

sparsh garg 2021-9-1

M_raw.mat

thanks for the discussion.

Two things ,

the new code is still not generalizing and fails on the foll test case

Moreover,for the current question what I want is that when we do set(gca,'YDir','reverse),the resultant points that show up on the figure,that is the correct order I want.

So in order to do that what can I do,I have tried rotating the original set of reordered points(from your code) by a rotation matrix but that doesn't work,

Wan Ji 2021-9-1

在 MATLAB Online 中打开

Well, this is not a problem, you just need a photo size to do this then

plot(pts(1,:),max(pts(2,:))+1-pts(2,:));
% set(gca,'YDir','reverse');
ax=gca;
h = findobj(gca,'Type','line');
x = h.XData; 
y = h.YData;
Final_set_pts=[x;y];

请先登录，再进行评论。

Save points or data in right order

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

采纳的回答

2 个评论
显示无隐藏无

更多回答（0 个）

类别

标签

Community Treasure Hunt

Save points or data in right order

1 个评论 显示 -1更早的评论 隐藏 -1更早的评论

采纳的回答

2 个评论 显示 无 隐藏 无

更多回答（0 个）

类别

标签

另请参阅

Community Treasure Hunt

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

2 个评论
显示无隐藏无