绘制质心@每次迭代

Question

我有一个场景，在每次迭代时生成一个矩阵C。C矩阵维数为2xn，C矩阵中的每一列为二维质心，在C矩阵中有 n 质心。

由于每次迭代都更新了C矩阵，所以更新了质心。我想画出质心1(也就是column1)的运动图。通过在点之间画一个箭头，图应该指示质心1从前一次迭代到当前迭代的移动。

我试图在matlab中使用散射函数。

Answer 1

请考虑以下示例：

%# matrix of centroids
n = 5;
C = rand(2,n);

%# set up graphic objects
hScatter = gscatter(C(1,:), C(2,:), 1:n, [], [], 30); hold on
hQuiver = quiver(nan,nan,nan,nan);
set(hQuiver, 'AutoScale','off', 'Color','k')
axis([-10 10 -10 10])
drawnow, pause(1)

%# update and show C each iteration
for i=1:10
    %# update centroids
    oldC = C;
    C = C + randn(size(C));

    %# update centroids to new locations
    set(hScatter, {'XData'},num2cell(C(1,:))', {'YData'},num2cell(C(2,:))')

    %# plot arrow showing movement from old to new locations
    set(hQuiver, 'XData',oldC(1,:), 'YData',oldC(2,:), ...
        'UData',C(1,:)-oldC(1,:), 'VData',C(2,:)-oldC(2,:))

    %# show iteration number
    title( sprintf('Iteration %d',i) )

    %# refresh plot
    drawnow, pause(1)
end

​

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Answer 2

我认为你应该看一看箭头函数，使用一些类似于plot()的东西，等等；

plot();hold on;
for i=1:iter
   arrow(C(old_iter),C(new_iter));
end;
hold off;