如何为条形图中的每个条形设置特定颜色

Question

我尝试为以下条形图中的每个条形选择特定颜色：

鉴于我们有以下带有变量的 pandas 系列win_corr：

fruity             -0.380938
hard               -0.310382
pluribus           -0.247448
nougat              0.199375
caramel             0.213416
crispedricewafer    0.324680
peanutyalmondy      0.406192
bar                 0.429929
chocolate           0.636517
Name: winpercent, dtype: float64

为了可视化，我使用以下代码：

fig, ax = plt.subplots(figsize=(8,6))
ax = sns.barplot(win_corr.values,win_corr.index, orient='h', color='deepskyblue') 
ax.set_ylabel('')    
ax.set_xlabel('Value')
plt.title('Correlation Coefficients for winpercent')
ax.bar_label(ax.containers[0], fmt= '%0.1f', label_type='center' )
#ax[0].set_color['r'] # did not work to change the color
plt.show()

为了改变颜色，我尝试了 类似问题的以下解决方案：

color = ['black','red','green','orange','blue','limegreen','darkgreen','royalblue','navy']


fig, ax = plt.subplots(figsize=(8,6))
ax = sns.barplot(win_corr.values,win_corr.index, orient='h', color=color) # did NOT work 
ax.set_ylabel('')    
ax.set_xlabel('Value')
plt.title('Correlation Coefficients for winpercent')
ax.bar_label(ax.containers[0], fmt= '%0.1f', label_type='center' )

plt.show()

我有以下错误消息：

ValueError                                Traceback (most recent call last)
<ipython-input-51-e266cc052512> in <module>()
      3 
      4 fig, ax = plt.subplots(figsize=(8,6))
----> 5 ax = sns.barplot(win_corr.values,win_corr.index, orient='h', color=color) # did NOT work
      6 ax.set_ylabel('')
      7 ax.set_xlabel('Value')

9 frames
/usr/local/lib/python3.7/dist-packages/matplotlib/colors.py in _to_rgba_no_colorcycle(c, alpha)
    269         raise ValueError(f"Invalid RGBA argument: {orig_c!r}")
    270     if len(c) not in [3, 4]:
--> 271         raise ValueError("RGBA sequence should have length 3 or 4")
    272     if not all(isinstance(x, Number) for x in c):
    273         # Checks that don't work: `map(float, ...)`, `np.array(..., float)` and

ValueError: RGBA sequence should have length 3 or 4

Answer 1

使用palette参数代替color. hue从Seaborn 0.13版本开始，使用时还需要设置参数palette。

import seaborn as sns
import pandas as pd
import matplotlib.pyplot as plt

# sample data
data = {'fruity': -0.380938, 'hard': -0.310382, 'pluribus': -0.247448,
        'nougat': 0.199375, 'caramel': 0.213416, 'crispedricewafer': 0.32468,
        'peanutyalmondy': 0.406192, 'bar': 0.429929, 'chocolate': 0.636517}
win_corr = pd.Series(data)

color = ['black','red','green','orange','blue','limegreen','darkgreen','royalblue','navy']

fig, ax = plt.subplots(figsize=(8,6))
ax = sns.barplot(x=win_corr.values, y=win_corr.index, hue=win_corr.index, orient='h', palette=color, dodge=False)
ax.set_ylabel('')    
ax.set_xlabel('Value')
plt.title('Correlation Coefficients for winpercent')
ax.bar_label(ax.containers[0], fmt= '%0.1f', label_type='center' )

plt.show()