来自 pandas 数据框的散点图上的 Matplotlib 图例 [英] Matplotlib Legend on Scatterplot from pandas dataframe

问题描述

我正在尝试在下图上正确显示图例.它应该只是带有相应颜色的绿色"、蓝色"和红色".但这到处都是.

代码如下:

 将熊猫作为pd导入导入matplotlib.pyplot作为pltdf = pd.DataFrame({'类别':['蓝色'，'绿色'，'红色'，'蓝色'，'绿色'，'红色'，'蓝色'，'绿色'，'红色']，'尝试':[8955,7881,6723,100,200,300,4567,876,54],'成功':[3000,7500,2000，256,4567,4567,7665,543,43]})fig，ax = plt.subplots()plt.scatter(df['attempts'],df['success'],c=df['category'],label=df['category'])plt.legend(loc = 2)plt.savefig('scatter.png')plt.show()

如何正确处理?(这里有一个类似的:

或者纯 matplotlib:

fig,ax = plt.subplots()对于 df.groupby('category') 中的 k,d:ax.scatter(d ['attempts']，d ['success']，label = k)plt.legend(loc = 2)plt.savefig('scatter.png')plt.show()

输出:

I am trying to get the legend right on the figure below. It should be just 'green', 'blue' and 'red' with the corresponding color. But it is all over the place.

the code is below:

import pandas as pd
import matplotlib.pyplot as plt

df = pd.DataFrame({
        'category':['blue','green','red','blue','green','red','blue','green','red'],
        'attempts':[8955,7881,6723,100,200,300,4567,876,54],
        'success':[3000,7500,2000, 256,4567,4567,7665,543,43]
})
fig,ax = plt.subplots()
plt.scatter(df['attempts'],df['success'],c=df['category'],label=df['category'])
plt.legend(loc=2)
plt.savefig('scatter.png')
plt.show()

How do I get this right? (There is a similar one here: https://pythonspot.com/matplotlib-scatterplot/ in the second part "Scatter plot with groups", but this is not based on pandas dataframe).

解决方案

You can use seaborn's scatterplot:

fig,ax = plt.subplots()
sns.scatterplot(data=df, hue='category', x='attempts', y='success')
plt.legend(loc=2)
plt.savefig('scatter.png')
plt.show()

Output:

Or pure matplotlib:

fig,ax = plt.subplots()
for k,d in df.groupby('category'):
    ax.scatter(d['attempts'], d['success'], label=k)
plt.legend(loc=2)
plt.savefig('scatter.png')
plt.show()

output:

这篇关于来自 pandas 数据框的散点图上的 Matplotlib 图例的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！