mirror of
https://github.com/apachecn/ailearning.git
synced 2026-04-26 11:35:24 +08:00
814 lines
54 KiB
Markdown
814 lines
54 KiB
Markdown
# figures, subplots, axes 和 ticks 对象
|
||
|
||
## figures, axes 和 ticks 的关系
|
||
|
||
这些对象的关系可以用下面的图来表示：
|
||
|
||
示例图像：
|
||
|
||
|
||
|
||
具体结构：
|
||
|
||
|
||
|
||
## figure 对象
|
||
|
||
`figure` 对象是最外层的绘图单位，默认是以 `1` 开始编号（**MATLAB** 风格，`Figure 1, Figure 2, ...`），可以用 `plt.figure()` 产生一幅图像，除了默认参数外，可以指定的参数有：
|
||
|
||
* `num` - 编号
|
||
* `figsize` - 图像大小
|
||
* `dpi` - 分辨率
|
||
* `facecolor` - 背景色
|
||
* `edgecolor` - 边界颜色
|
||
* `frameon` - 边框
|
||
|
||
这些属性也可以通过 `Figure` 对象的 `set_xxx` 方法来改变。
|
||
|
||
## subplot 和 axes 对象
|
||
|
||
### subplot
|
||
|
||
`subplot` 主要是使用网格排列子图：
|
||
|
||
In [1]:
|
||
|
||
```py
|
||
%pylab inline
|
||
|
||
subplot(2,1,1)
|
||
xticks([]), yticks([])
|
||
text(0.5,0.5, 'subplot(2,1,1)',ha='center',va='center',size=24,alpha=.5)
|
||
|
||
subplot(2,1,2)
|
||
xticks([]), yticks([])
|
||
text(0.5,0.5, 'subplot(2,1,2)',ha='center',va='center',size=24,alpha=.5)
|
||
|
||
show()
|
||
|
||
```
|
||
|
||
```py
|
||
Populating the interactive namespace from numpy and matplotlib
|
||
|
||
```
|
||
|
||
|
||
|
||
更高级的可以用 `gridspec` 来绘图：
|
||
|
||
In [2]:
|
||
|
||
```py
|
||
import matplotlib.gridspec as gridspec
|
||
|
||
G = gridspec.GridSpec(3, 3)
|
||
|
||
axes_1 = subplot(G[0, :])
|
||
xticks([]), yticks([])
|
||
text(0.5,0.5, 'Axes 1',ha='center',va='center',size=24,alpha=.5)
|
||
|
||
axes_2 = subplot(G[1,:-1])
|
||
xticks([]), yticks([])
|
||
text(0.5,0.5, 'Axes 2',ha='center',va='center',size=24,alpha=.5)
|
||
|
||
axes_3 = subplot(G[1:, -1])
|
||
xticks([]), yticks([])
|
||
text(0.5,0.5, 'Axes 3',ha='center',va='center',size=24,alpha=.5)
|
||
|
||
axes_4 = subplot(G[-1,0])
|
||
xticks([]), yticks([])
|
||
text(0.5,0.5, 'Axes 4',ha='center',va='center',size=24,alpha=.5)
|
||
|
||
axes_5 = subplot(G[-1,-2])
|
||
xticks([]), yticks([])
|
||
text(0.5,0.5, 'Axes 5',ha='center',va='center',size=24,alpha=.5)
|
||
|
||
show()
|
||
|
||
```
|
||
|
||
|
||
|
||
## axes 对象
|
||
|
||
`subplot` 返回的是 `Axes` 对象，但是 `Axes` 对象相对于 `subplot` 返回的对象来说要更自由一点。`Axes` 对象可以放置在图像中的任意位置：
|
||
|
||
In [3]:
|
||
|
||
```py
|
||
axes([0.1,0.1,.8,.8])
|
||
xticks([]), yticks([])
|
||
text(0.6,0.6, 'axes([0.1,0.1,.8,.8])',ha='center',va='center',size=20,alpha=.5)
|
||
|
||
axes([0.2,0.2,.3,.3])
|
||
xticks([]), yticks([])
|
||
text(0.5,0.5, 'axes([0.2,0.2,.3,.3])',ha='center',va='center',size=16,alpha=.5)
|
||
|
||
show()
|
||
|
||
```
|
||
|
||
In [4]:
|
||
|
||
```py
|
||
axes([0.1,0.1,.5,.5])
|
||
xticks([]), yticks([])
|
||
text(0.1,0.1, 'axes([0.1,0.1,.8,.8])',ha='left',va='center',size=16,alpha=.5)
|
||
|
||
axes([0.2,0.2,.5,.5])
|
||
xticks([]), yticks([])
|
||
text(0.1,0.1, 'axes([0.2,0.2,.5,.5])',ha='left',va='center',size=16,alpha=.5)
|
||
|
||
axes([0.3,0.3,.5,.5])
|
||
xticks([]), yticks([])
|
||
text(0.1,0.1, 'axes([0.3,0.3,.5,.5])',ha='left',va='center',size=16,alpha=.5)
|
||
|
||
axes([0.4,0.4,.5,.5])
|
||
xticks([]), yticks([])
|
||
text(0.1,0.1, 'axes([0.4,0.4,.5,.5])',ha='left',va='center',size=16,alpha=.5)
|
||
|
||
show()
|
||
|
||
```
|
||
|
||
|
||
|
||
后面的 `Axes` 对象会覆盖前面的内容。
|
||
|
||
## ticks 对象
|
||
|
||
ticks 用来注释轴的内容，我们可以通过控制它的属性来决定在哪里显示轴、轴的内容是什么等等。 |