图最小二乘法

Question

这是我用最小二乘法绘制的回归线的倍频程曲线图。

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有没有办法添加类似于小箭头或线的方法来将点与实际线连接起来？这里有一个我希望它看起来是什么样子的例子。谢谢

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Answer 1

我不认为有一个特定的函数来绘制残差，但手动完成它是相当简单的：

% Let's assume this is our model, predicting y from x
  model = @sin;

% Define the x domain, which will be used for plotting
  xdomain = 0:0.1:10;

% Define some (x,y) input points
  xpoints = 10 * rand(1, 10);
  ypoints = model(xpoints) + 0.5 * randn(size(xpoints));

% Plot model
  plot( xdomain, model(xdomain), 'k-', 'linewidth', 1.5 );
  hold on;

% Plot input points
  plot( xpoints, ypoints, 'ko', 'markersize', 8, 'markeredgecolor', 'k', 'markerfacecolor', [0.4,0.4,0.4], 'linewidth', 1.5 )

% Plot residual lines
  plot( [xpoints;xpoints], [model(xpoints);ypoints], 'k:', 'linewidth', 1.5 )
  hold off;