How to connect points in a dynamic figure

Hi,

I am working on a project that dynamically scans and plots new points to a chart. I need to connect the points that fit specific criteria.

E.g, when the distance between any pair of points is less than or equal to 2, the two points are connected. Now points (0,0) and (0,4) are plotted already. If the next scanned point is (2,0), how shall I connect the point with the other two?

Thanks in advance! :)

[Walter Roberson]

Did you look at the existing routines from the File Exchange?

http://www.mathworks.com/matlabcentral/fileexchange/?term=tag%3Adigitize

Answer 1

[Daksh]

I understand that you wish to connect pairs of dynamically added points with a line to a given plot figure if the Euclidean distance between the added point and any existing points is <=2.

Kindly refer to the code below:

% plotting the original graph 
x=[0 0; 0 4]; 
hold on 
for i=1:length(x) 
    plot(x(i,1),x(i,2), 'or') 
end

Now let's assume we dynamically create a new point (0,2) and store it to variable 'y' in workspace, and now we want to connect point y to all existing points in the graph with pairwise Euclidean distance <=2. This is how it can be done:

% New point added
y=[0,2]; 

x1=y(1); 
y1=y(2); 
plot(x1,y1, 'ob') 

for i=1:length(x) 
    x2=x(i,1); 
    y2=x(i,2); 
    if(sqrt((x1-x2)^2 + (y1-y2)^2) <=2) 
        plot([x1,x2], [y1,y2], 'b-', 'LineWidth', 2); 
    end 
    x(length(x)+1,1)=x1; 
    x(length(x)+1,2)=y1; 
end 
hold off 

Hope it helps!