plt.xscale、plt.yscale将 x轴和 y轴的比例设置为对数比例

àì夳堔傛蜴生んèń 2022-10-15 07:58 420阅读 0赞

### 目录 ###

*  1、x、y轴可定义多种形式比例标注
 *  2、例子展示：
 *  3、\`matplotlib.scale.SymmetricalLogScale\`变换底数等参数
 *  Notes

# 1、x、y轴可定义多种形式比例标注 #

一般的，x轴的取值都是以固定的值（例如1）增长的，但是在 log 运算后，x轴的取值就会以一个量级增长。例如，以10的指数增长。

# 2、例子展示： #

import matplotlib.pyplot as plt
    import numpy as np
    
    dt = 0.01
    x = np.arange(-50.0, 50.0, dt)
    y = np.arange(0, 100.0, dt)
    
    plt.subplot(311)
    plt.plot(x, y)
    plt.xscale('symlog')
    plt.ylabel('symlogx')
    plt.grid(True)
    plt.gca().xaxis.grid(True, which='minor')  # minor grid on too
    
    plt.subplot(312)
    plt.plot(y, x)
    plt.yscale('symlog')
    plt.ylabel('symlogy')
    
    plt.subplot(313)
    plt.plot(x, np.sin(x / 3.0))
    plt.xscale('symlog')
    plt.yscale('symlog', linthreshy=0.015)
    plt.grid(True)
    plt.ylabel('symlog both')
    
    plt.tight_layout()
    plt.show()

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTI4ODU1Nw_size_16_color_FFFFFF_t_70]

# 3、`matplotlib.scale.SymmetricalLogScale`变换底数等参数 #

<table> 
 <thead> 
  <tr> 
   <th><code>basex, basey : float</code></th> 
   <th>对数的底数，默认为10</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td><code>linthreshx, linthreshy : float</code></td> 
   <td>定义范围 (-x, x), within which the plot is linear. 避免了使绘图趋于零附近的无穷大。默认为 2</td> 
  </tr> 
  <tr> 
   <td><code>subsx, subsy : sequence of int</code></td> 
   <td>每个主要刻度之间的子刻度线的放置位置。<strong>For example,</strong> in a log10 scale: [2, 3, 4, 5, 6, 7, 8, 9] will place 8 logarithmically spaced minor ticks between each major tick.</td> 
  </tr> 
  <tr> 
   <td><code>linscalex, linscaley : float, optional</code></td> 
   <td>允许线性范围（-linthresh，linthresh）相对于对数范围进行拉伸。Its value is the number of decades to use for each half of the linear range. <strong>For example</strong>, when linscale == 1.0 (the default), the space used for the positive and negative halves of the linear range will be equal to one decade in the logarithmic range.</td> 
  </tr> 
 </tbody> 
</table>

# Notes #

*  By default, Matplotlib supports the above mentioned scales. Additionally, custom scales may be registered using [matplotlib.scale.register\_scale][matplotlib.scale.register_scale].
 *  xscale函数的返回值为(locs, labels)元组。其中locs为X轴刻度位置列表，labels为X轴刻度标签列表
 *  `plt.xscale('log')`、`plt.yscale('symlog')`的参数还有：`{"linear", "log", "symlog", "logit", ...}`
    
     *  `'log'`,A standard logarithmic scale. Care is taken to only plot positive values.注意**仅绘制正值**
     *  `'symlog'`,The symmetrical logarithmic scale is logarithmic in both the positive and negative directions from the origin.对称对数刻度在**从原点开始的正向和负向都是对数的**。

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTI4ODU1Nw_size_16_color_FFFFFF_t_70]: /images/20221014/fee5074963b742f9ac3fdf7cfca3e420.png
[matplotlib.scale.register_scale]: https://matplotlib.org/3.1.1/api/scale_api.html#matplotlib.scale.register_scale