python - 如何在 Pandas DataFrame 散点图中添加图例？

Question

我有一个包含以下列感兴趣的 Pandas DataFrame:

['Relative Width', 'Relative Height', 'Object Name', 'Object ID']

用 df.plot(c='Object ID') 确定了 15 个对象名称和 15 种颜色。产生下图:



我想显示一个带有 15 个对象名称的图例，如何做到这一点？

import matplotlib.pyplot as plt
from annotation_parsers import parse_voc_folder


def visualize_box_relative_sizes(folder_path, voc_conf, cache_file='data_set_labels.csv'):
    frame = parse_voc_folder(folder_path, voc_conf, cache_file)
    title = f'Relative width and height for {frame.shape[0]} boxes.'
    frame.plot(
        kind='scatter',
        x='Relative Width',
        y='Relative Height',
        title=title,
        c='Object ID',
        colormap='gist_rainbow',
        colorbar=False,
    )
    plt.show()

根据 wwnde 的建议，我将代码更改为以下内容:

def visualize_box_relative_sizes(folder_path, voc_conf, cache_file='data_set_labels.csv'):
    frame = parse_voc_folder(folder_path, voc_conf, cache_file)
    title = f'Relative width and height for {frame.shape[0]} boxes.'
    sns.scatterplot(x=frame["Relative Width"], y=frame["Relative Height"], hue=frame["Object Name"])
    plt.title(title)
    plt.show()

产生以下结果:

Answer 1

请尝试

fig, ax = plt.subplots()

ax = sns.scatterplot(x="total_bill", y="tip",
                     hue="size", size="size",
                     data=tips)
ax.set_title('title')
plt.show()

这应该给你一个默认的彩色图例