python config_error ai_generated true

ValueError: 'viridis_r' is not a valid value for cmap; supported values are: 'viridis', 'plasma', ...

ID: python/matplotlib-cmap-not-recognized

Also available as: JSON · Markdown · 中文
80%Fix Rate
87%Confidence
0Evidence
2024-10-02First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

Passing a colormap name that matplotlib does not recognize, often due to a typo or a colormap registered by a different library (e.g., cmocean) that is not installed.

generic

中文

传入了 matplotlib 无法识别的 colormap 名称，通常是由于拼写错误或由其他库（如 cmocean）注册但未安装的 colormap。

Workarounds

  1. 95% success 
    import matplotlib.pyplot as plt
print(list(plt.colormaps()))
ax.imshow(data, cmap='viridis_r')
  2. 90% success 
    pip install cmocean
import cmocean
ax.imshow(data, cmap='cmo.thermal')

Dead Ends

Common approaches that don't work:

  1. 80% fail

    Falls back to the default colormap, silently changing the intended visualization.

  2. 90% fail

    Also invalid; the correct suffix is '_r'.