mykdtree.m

用matlab实现的kdtree

function leaf = kdtree(pointsets,level)
if isempty(pointsets)
    return;
end
n_points = size(pointsets); 
n_points = n_points(2);
points1 = [];
points2 = [];

if n_points == 1
    
    leaf.data = pointsets;
    leaf.right = 0;
    leaf.left = 0;
    leaf.level = level;
    return;
else
    if mod(level,2) == 0
        meanvaluex = mean(pointsets(1,:));
        for i=1:n_points
            if pointsets(1,i) <= meanvaluex
                points1 = [points1 pointsets(:,i)];
            else 
                points2 = [points2 pointsets(:,i)];
            end
        end
    else
        meanvaluey = mean(pointsets(2,:));
        for i=1:n_points
            if pointsets(2,i) >= meanvaluey
                points1 = [points1 pointsets(:,i)];
            else 
                points2 = [points2 pointsets(:,i)];
            end
        end
    end
    leafleft = mykdtree(points1, level+1);
    leafright = mykdtree(points2, level+1);
end

leaf.left = leafleft;
leaf.right = leafright;
leaf.level = level;