matplotlib & pandas

Python/matplotlab/gallery/mplot3d/quiver3d.md

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+# 3D箭袋图像
+
+演示在3d网格上的点处绘制方向箭头。
+
+![3D箭袋图像示例](https://matplotlib.org/_images/sphx_glr_quiver3d_001.png)
+
+```python
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+fig = plt.figure()
+ax = fig.gca(projection='3d')
+
+# Make the grid
+x, y, z = np.meshgrid(np.arange(-0.8, 1, 0.2),
+                      np.arange(-0.8, 1, 0.2),
+                      np.arange(-0.8, 1, 0.8))
+
+# Make the direction data for the arrows
+u = np.sin(np.pi * x) * np.cos(np.pi * y) * np.cos(np.pi * z)
+v = -np.cos(np.pi * x) * np.sin(np.pi * y) * np.cos(np.pi * z)
+w = (np.sqrt(2.0 / 3.0) * np.cos(np.pi * x) * np.cos(np.pi * y) *
+     np.sin(np.pi * z))
+
+ax.quiver(x, y, z, u, v, w, length=0.1, normalize=True)
+
+plt.show()
+```
+
+## 下载这个示例
+            
+- [下载python源码: quiver3d.py](https://matplotlib.org/_downloads/quiver3d.py)
+- [下载Jupyter notebook: quiver3d.ipynb](https://matplotlib.org/_downloads/quiver3d.ipynb)