How to iterate until a point satisfies a certain condition?

Question

Loren99 2022-6-21

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1745230-how-to-iterate-until-a-point-satisfies-a-certain-condition

评论： Walter Roberson 2022-6-29

Hi everyone! I need a suggestion for this code. I have this code:

x = [1,2,2,2,1;2,3,2,1,1];
y = [1,1,1,2,2;1,1,2,2,1];
plot(x,y,'-x')
xlim([0,3])
ylim([0,3])
axis equal

Applying this procedure, I obtain that the points that are unique such as (3;1) are removed. The code is this one:

%converts to points with x,y coordinates
points = [x(1,:),x(2,:);y(1,:),y(2,:)]; 
%initialize test array
repeat_arr = zeros(size(points,2),size(points,2));
for i_points = 1:size(points,2)
    %find if a point is repeated excluding itself
    repeat_arr(i_points,[1:i_points-1,i_points+1:end]) = all(points(:,i_points)==points(:,[1:i_points-1,i_points+1:end]),1) ;
end
% now we know for each points if it is repeated
temp = any(repeat_arr,1); 
%Reverse the segment to point process so we can mask any segment that does not have a repeated point
edge_mask = all([temp(1:end/2); temp(end/2+1:end)]);
%Create X Y array of segment using out mask
x_edges = x(:,edge_mask);
y_edges = y(:,edge_mask);
plot(x_edges,y_edges,'-x')
xlim([0,3])
ylim([0,3])
axis equal

However, my question is: let us imagine that I have also a point of coordinates (2.5;1) like the one in the figure below, and that using this procedure I am able to remove the point (3;1). After this pruning, I would like the procedure to iterate until also the point (2.5;1) (that now is unique) is excluded and therefore execute as long as only the points in common to two or more segments remain. How can I do this in the most general way possible to be able to adapt it to other more complicated situations with more segments? I think that I need a while loop but, how can I set the condition?