python - 如何在条形图顶部显示值[重复]

Question

这里是 Python 新手。我想在下图中显示每个 bin 上方的值：

这是我的代码：

x=[i for i in range(1,11)]
y=[0.95,
0.95,
0.89,
0.8,
0.74,
0.65,
0.59,
0.51,
0.5,
0.48]

plt.bar(x, height= y)
xlocs, xlabs = plt.xticks()
xlocs=[i+1 for i in range(0,10)]
xlabs=[i/2 for i in range(0,10)]
plt.xlabel('Max Sigma')
plt.ylabel('Test Accuracy')
plt.xticks(xlocs, xlabs)
plt.show()

这是我想要的图表：

Answer 1

试试：

plt.rcParams['xtick.bottom'] = plt.rcParams['xtick.labelbottom'] = False plt.rcParams['xtick.top'] = plt.rcParams['xtick.labeltop'] = True This makes it simple

Answer 2

plt.text() 将允许您向图表添加文本。它只允许您一次将文本添加到一组坐标，因此您需要遍历数据以为每个条添加文本。

以下是我对您的代码所做的主要调整：

# assign your bars to a variable so their attributes can be accessed
bars = plt.bar(x, height=y, width=.4)

# access the bar attributes to place the text in the appropriate location
for bar in bars:
    yval = bar.get_height()
    plt.text(bar.get_x(), yval + .005, yval)

我将.005 添加到 y 值，以便将文本放置在条形上方。这可以修改以获得您正在寻找的外观。

以下是基于原始代码的完整工作示例。我做了一些修改以使其不那么脆弱：

import matplotlib.pyplot as plt

# set the initial x-values to what you are wanting to plot
x=[i/2 for i in range(10)]
y=[0.95,
0.95,
0.89,
0.8,
0.74,
0.65,
0.59,
0.51,
0.5,
0.48]

bars = plt.bar(x, height=y, width=.4)

xlocs, xlabs = plt.xticks()

# reference x so you don't need to change the range each time x changes
xlocs=[i for i in x]
xlabs=[i for i in x]

plt.xlabel('Max Sigma')
plt.ylabel('Test Accuracy')
plt.xticks(xlocs, xlabs)

for bar in bars:
    yval = bar.get_height()
    plt.text(bar.get_x(), yval + .005, yval)

plt.show()

Answer 3

简单添加

for i, v in enumerate(y):
    plt.text(xlocs[i] - 0.25, v + 0.01, str(v))

在plt.show() 之前。您可以通过分别更改 (-0.25) 和 (0.01) 值来调整文本的集中度或高度。