问题

我正在尝试将两个文本框并排放在matplotlib图形的右上角。我遵循了这个文本对齐的教程，可以将一个文本框放在右上角。但我不知道如何添加第二个文本框，使得左上角框的右边缘与右上角框的左边缘相交。

以下是运行最小工作示例的代码：

import numpy as np
import matplotlib.pyplot as plt

# 数据
x = np.linspace(-10, 10, 51)
shrink_factors = np.linspace(1, 0, x.size)
y1 = shrink_factors*np.sin(np.exp(-x))
y2 = shrink_factors*np.cos(np.exp(-x))

# 获取绘图参数
xlim = [np.min(x), np.max(x)]
ylim = [0, 1.125*np.max([np.max(y1), np.max(y2)])]
facecolors = ("red", "blue")
(color1, color2) = facecolors
label1 = "Label 1"
label2 = "Label 2"
text1 = "RED 1"
text2 = "BLUE 2"
text_background_color = "gainsboro"
text_size = 12
figsize = (12, 7)

# 初始化图
fig, ax = plt.subplots(
    figsize=figsize)

# 绘制数据
ax.plot(x, y1, color=color1, label=label1)
ax.plot(x, y2, color=color2, label=label2)
ax.grid(color="black", linestyle=":", alpha=0.3)
ax.set_xlim(xlim)
ax.set_ylim(ylim)
fig.legend(mode="expand", loc="lower center", ncol=2)

# 并排添加文本框
text_box1 = ax.text(0.95, 0.95, text1, 
                    color=color1, 
                    fontsize=text_size,
                    horizontalalignment="right", 
                    verticalalignment="top", 
                    transform=ax.transAxes)
text_box1.set_bbox({"facecolor": text_background_color, "edgecolor": "black"})
text_box1_pos = text_box1.get_position()
text_box2 = ax.text(text_box1_pos[0], 0.95, text2, 
                    color=color2, 
                    fontsize=text_size, 
                    horizontalalignment="left", 
                    verticalalignment="top", 
                    transform=ax.transAxes)
text_box2.set_bbox({"facecolor": text_background_color, "edgecolor": "black"})

# 完成绘图
plt.show()
plt.close()

import numpy as np
import matplotlib.pyplot as plt

# data
x = np.linspace(-10, 10, 51)
shrink_factors = np.linspace(1, 0, x.size)
y1 = shrink_factors*np.sin(np.exp(-x))
y2 = shrink_factors*np.cos(np.exp(-x))

# get plot parameters
xlim = [np.min(x), np.max(x)]
ylim = [0, 1.125*np.max([np.max(y1), np.max(y2)])]
facecolors = ("red", "blue")
(color1, color2) = facecolors
label1 = "Label 1"
label2 = "Label 2"
text1 = "RED 1"
text2 = "BLUE 2"
text_background_color = "gainsboro"
text_size = 12
figsize = (12, 7)
# figsize = (7, 12)

# initialize plot
fig, ax = plt.subplots(
    figsize=figsize)

# plot data
ax.plot(x, y1, color=color1, label=label1)
ax.plot(x, y2, color=color2, label=label2)
ax.grid(color="black", linestyle=":", alpha=0.3)
ax.set_xlim(xlim)
ax.set_ylim(ylim)
fig.legend(mode="expand", loc="lower center", ncol=2)

# add text-boxes side-by-side
text_box1 = ax.text(0.95, 0.95, text1, 
                    color=color1, 
                    fontsize=text_size,
                    horizontalalignment="right", 
                    verticalalignment="top", 
                    transform=ax.transAxes)
text_box1.set_bbox({"facecolor": text_background_color, "edgecolor": "black"})
text_box1_pos = text_box1.get_position()
text_box2 = ax.text(text_box1_pos[0], 0.95, text2, 
                    color=color2, 
                    fontsize=text_size, 
                    horizontalalignment="left", 
                    verticalalignment="top", 
                    transform=ax.transAxes)
text_box2.set_bbox({"facecolor": text_background_color, "edgecolor": "black"})

# finish plot
plt.show()
plt.close()

答案1

得分: 3

你想将左侧框右对齐到右侧框的左侧 x 值。因此，您需要获取围绕文本框绘制的矩形。它们由一个与变异比例尺度相关的 pad 值填充。要获取这些值，您首先需要绘制图形（可以在不渲染的情况下完成以加快速度）。

以下是一个假设两个文本使用相同（默认）填充的最小示例：

import matplotlib.pyplot as plt

fig, ax = plt.subplots()

bbox_kwds = dict(fc="gainsboro", ec="black")
text_box1 = ax.text(0.95, 0.95, "RIGHT", ha="right", va="top", transform=ax.transAxes, bbox=bbox_kwds)

fig.draw_without_rendering()
pad = text_box1.get_bbox_patch().get_boxstyle().pad * text_box1.get_bbox_patch().get_mutation_scale()
x = ax.transAxes.inverted().transform(text_box1.get_bbox_patch().get_window_extent().p0 - [pad, 0])[0]

text_box2 = ax.text(x, 0.95, "LEFT", ha="right", va="top", transform=ax.transAxes, bbox=bbox_kwds)

<details>
<summary>英文:</summary>
You want to right-align the left box to the left x value of the right box. So you need to get the rectangles drawn around the text boxes. They are padded by a value of pad scaled with a mutation scale factor. To get these values you first need to draw the figure (you can do it without rendering to speed it up a bit).
Here is a minimal examples assuming both texts using the same (default) padding:
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
bbox_kwds = dict(fc=&quot;gainsboro&quot;, ec=&quot;black&quot;)
text_box1 = ax.text(0.95, 0.95, &quot;RIGHT&quot;, ha=&quot;right&quot;, va=&quot;top&quot;, transform=ax.transAxes, bbox=bbox_kwds)
fig.draw_without_rendering()
pad = text_box1.get_bbox_patch().get_boxstyle().pad * text_box1.get_bbox_patch().get_mutation_scale()
x = ax.transAxes.inverted().transform(text_box1.get_bbox_patch().get_window_extent().p0 - [pad, 0])[0]
text_box2 = ax.text(x, 0.95, &quot;LEFT&quot;, ha=&quot;right&quot;, va=&quot;top&quot;, transform=ax.transAxes, bbox=bbox_kwds)
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/bZzJA.png
</details>
# 答案2
**得分**: 2
这是我之前遇到过的一个类似问题。这是我所做的事情...这是基于另一篇帖子中提供的一些信息[这里](https://stackoverflow.com/questions/24581194/matplotlib-text-bounding-box-dimensions)。以下是对你的代码的更新...
1. 更新第一个文本框的x位置为`0.9`，以便两个标签都在图中。
2. 一旦绘制了第一个文本框，请添加下面的代码...这类似于我提到的帖子中所解释的。请注意，我正在使用`transAxes`，以便在任何地方都有相同的坐标。更多信息[在这里](https://matplotlib.org/stable/tutorials/advanced/transforms_tutorial.html)。请注意，`bb_datacoords`现在将具有第一个文本框的x和y坐标。
```python
# text_box1_pos = text_box1.get_position()  --&gt; 你的代码，不再需要
r = fig.canvas.get_renderer()
transf = ax.transAxes.inverted()
bb = text_box1.get_window_extent(renderer = r)
bb_datacoords = bb.transformed(transf)

3. 使用bbox的x1位置作为第二个文本框的起点，如下所示...

    bb_datacoords.x1+0.01, #text_box1_pos[0],

请注意，正如上述SO答案中所提到的，精确位置在绘图完成之前是未知的，因此可以添加一个小的增量0.01，使它们不重叠。如果你想在两个框之间看到一个小间隙，可以增加它（比如0.02）。

生成的图表如下所示...希望对你有所帮助。

#text_box1_pos = text_box1.get_position()  --> You code, not required anymore
r = fig.canvas.get_renderer()
transf = ax.transAxes.inverted()
bb = text_box1.get_window_extent(renderer = r)
bb_datacoords = bb.transformed(transf)

    bb_datacoords.x1+0.01, #text_box1_pos[0],