箱线图的解释

Question

我正在尝试使用 python 的 matplotlib 库创建一个箱线图。代码如下。

fig, ax = plt.subplots(figsize=(8, 6))
bp = ax.boxplot([corr_df['bi'], corr_df['ndsi'], corr_df['dbsi'], corr_df['mbi']], patch_artist = True, notch ='True', vert = 1)
ax.set_title("Spearman’s correlation coefficient for Soil indices", fontsize=14)
ax.set_xlabel("Indices", fontsize=14)
ax.set_ylabel("Spearman’s correlation coefficient", fontsize=14)
colors = ['#088A08', '#FFFF00','#01DFD7', '#FF00FF', '#3A01DF']
for patch, color in zip(bp['boxes'], colors):
    patch.set_facecolor(color)
ax.grid()
ax.set_xticklabels(['bi', 'ndsi', 'dbsi', 'mbi'])

这会创建一个像这样的图像：

我无法理解第一个和第三个箱线图。这两个（bi 和 dbsi 的箱线图）中有颈状结构，而其他两个箱线图没有。 这说明了什么？网上描述的箱线图解释不包括这部分。

Answer 1

在您的示例中，参数 notch 设置为 True 因此根据 doc, 它显示：

notch bool, default: False
Whether to draw a notched boxplot (True), or a rectangular boxplot (False). The notches represent the confidence interval (CI) around the median. The documentation for bootstrap describes how the locations of the notches are computed by default, but their locations may also be overridden by setting the conf_intervals parameter.

具体来说，您所描述的行为（翻转外观）记录如下：

Note

In cases where the values of the CI are less than the lower quartile or greater than the upper quartile, the notches will extend beyond the box, giving it a distinctive "flipped" appearance. This is expected behavior and consistent with other statistical visualization packages.

您将在此 answer 中找到更多详细信息。

箱线图的解释

Interpretation of boxplot

python

statistics

matplotlib

boxplot