<p>从<a href="https://matplotlib.org/users/whats_new.html#cyclic-colormaps" rel="noreferrer">matplotlib version 3.0</a>开始,有内置的循环<a href="https://www.youtube.com/watch?v=xAoljeRJ3lU" rel="noreferrer">perceptually uniform colormaps</a>。好的,目前只有一个颜色映射,但是有两个选择开始和结束,即<a href="https://matplotlib.org/tutorials/colors/colormaps.html#sphx-glr-tutorials-colors-colormaps-py" rel="noreferrer">^{<cd1>} and ^{<cd2>}</a>。</p>
<p>一个简短的例子来演示它们的外观:</p>
<pre><code>import matplotlib.pyplot as plt
import numpy as np
# example data: argument of complex numbers around 0
N = 100
re,im = np.mgrid[-1:1:100j, -1:1:100j]
angle = np.angle(re + 1j*im)
cmaps = 'twilight', 'twilight_shifted'
fig,axs = plt.subplots(ncols=len(cmaps), figsize=(9.5,5.5))
for cmap,ax in zip(cmaps,axs):
cf = ax.pcolormesh(re, im, angle, shading='gouraud', cmap=cmap)
ax.set_title(cmap)
ax.set_xlabel(r'$\operatorname{Re} z$')
ax.set_ylabel(r'$\operatorname{Im} z$')
ax.axis('scaled')
cb = plt.colorbar(cf, ax=ax, orientation='horizontal')
cb.set_label(r'$\operatorname{Arg} z$')
fig.tight_layout()
</code></pre>
<p>上图为:</p>
<p><a href="https://i.stack.imgur.com/maKXh.png" rel="noreferrer"><img src="https://i.stack.imgur.com/maKXh.png" alt="twilight and twilight_shifted colormaps in action"/></a></p>
<p>这些全新的彩色地图是对现有的感知一致(顺序)彩色地图集合的一个惊人的补充,即<em>viridis</em>,<em>plasma</em>,<em>inferno</em>,<em>magma</em>和<em>cividis</em>(最后一个是<a href="https://matplotlib.org/users/prev_whats_new/whats_new_2.2.html#cividis-colormap" rel="noreferrer">a new addition in 2.2</a>,它不仅感知一致,而且对色盲友好,但它应该尽可能接近色盲和非色盲的人)。</p>