Hello everyone. Now I come across such a problem: given the coordinates of all points of the closed curve acbd, now I want to find all points of the curve ACB and save them. The code I write is as follows, but there are always mistakes. I

Where M0 is the set of all points.

CODE:

dc=centroids(:,2);
   idx2=MO(:,1)>=-50;
   idx3=MO(:,1)<=100;
   idx4=MO(:,2)>=dc;
   dataC=MO(idx2,:);
   dataD=MO(idx3,:);
   dataE=MO(idx4,:);
   dataF=intersect(dataC,dataD,'rows');%Finding the intersection of dataF,
   dataG=intersect(dataF,dataE,'rows');%Finding the intersection of dataG

[Wesley]

The concrete expression is that dataE and dataG are empty sets.

[Wesley]

Or I think another way is to determine all the points of the curve ACB by the two lines larger than AB and AD.

[Wesley]

erro:The index at position 2 is outside the array boundary (cannot exceed 1).

[KSSV]

What error you get? In the mat file, centroids is not defined and MO is not defined. Show us the complete code which lead to your error along with the error.

[Wesley]

dataE=MO(idx4,:);There is something wrong with this code. I don't know how to correct it.

[Wesley]

idx3=MO(:,1)<=x;

idx4=MO(:,2)>=y;

Can we intercept data together?

[Wesley]

Or can ACB data be cut out by straight line AD and BD?

Answer 1

[darova]

Here is your data looks like

s = load('M0.mat');
[x,y] = deal(s.M(:,1),s.M(:,2));
plot(x,y)