find intersection between two data sets

I have a random signal, and somehow a zone where a study is going to be made, lets think about a circle representing the limit of this zone, If I want to know which of the samples of my signal is the first one inside the circle zone, Is there a function in Matlab that helps me in this task.

If it is not, what would you recomend to do this...

Saludos!

Answer 1

[Sven]

Hi Carlos, try this code:

dataset = rand(20,2);
zoneXY = rand(1,2);
zoneRadius = rand(1);
dists = sqrt(sum(bsxfun(@minus, dataset, zoneXY).^2,2));
inZone = dists < zoneRadius;
figure
plot(dataset(:,1),dataset(:,2),'.'), hold on
rectangle('Position',[zoneXY-zoneRadius zoneRadius*2 zoneRadius*2],'Curvature',[1 1])
if any(inZone)
    firstInZone = find(inZone,1,'first')
    plot(dataset(firstInZone,1),dataset(firstInZone,2),'gs')
    legend({'Data points','First Pt In Zone'})
end

Does it describe your problem and how to find an answer?

[Carlos A. Morales Rergis]

Perfecto!!! Muchas gracias...

thanks a lot!