Nearest Neighbor XY plot

A = [1.5, 5.4; 9.2, 3.3; 6.9, 11.1]

B = [2, 4; 8, 10; 12.9,17.1]

5 radius

[DGM]

What is the question?

[Keturah Palma]

how do i know the nearest neighbor function is working?

[DGM]

What nearest neighbor function? Are you referring to this?

https://www.mathworks.com/help/matlab/ref/graph.nearest.html

If so, I'm not really familiar with network theory tools. As A and B are non-integers, they aren't indices; what are they?

[Keturah Palma]

is there another way to do it?

Answer 1

[Image Analyst]

Not sure what function you're talking about. If you just want to find points in Set A that are closer than 5 to points in Set B, you can do this:

markerSize = 40;
A =  [1.5, 5.4; 9.2, 3.3; 6.9, 11.1]

A = 3×2

1.5000 5.4000 9.2000 3.3000 6.9000 11.1000

B = [2, 4; 8, 10; 12.9,17.1]

B = 3×2

2.0000 4.0000 8.0000 10.0000 12.9000 17.1000

% Plot A
plot(A(:, 1), A(:, 2), 'r.', 'MarkerSize', markerSize);
hold on;
% Plot B
plot(B(:, 1), B(:, 2), 'b.', 'MarkerSize', markerSize);
grid on;
distances = pdist2(A, B)

distances = 3×3

1.4866 7.9630 16.3355 7.2339 6.8066 14.2874 8.6267 1.5556 8.4853

for row = 1 : size(distances, 1)
    [r, c] = find(distances(row, :) <= 5);
    for k = 1 : length(c)
        xCoords = [A(row, 1), B(c(k), 1)];
        yCoords = [A(row, 2), B(c(k), 2)];
        line(xCoords, yCoords, 'Color', 'm', 'LineWidth', 2)
        fprintf('Drawing line between (%.1f, %.1f) and (%.1f, %.1f).  The distance is %.3f.\n', ...
            A(row, 1), A(row, 2), B(c(k), 1), B(c(k), 2), distances(row, c(k)))
    end
end

Drawing line between (1.5, 5.4) and (2.0, 4.0).  The distance is 1.487.

Drawing line between (6.9, 11.1) and (8.0, 10.0).  The distance is 1.556.

[Keturah Palma]

thank you