python - Mayavi contour3d 文档提到 "the arrows"时是什么意思？

Question

我了解如何在 mayavi 中绘制数据网格的轮廓，如下所示:

from mayavi import mlab
mlab.contour3d(my_data_grid)

但是，我很好奇该函数的其他签名是什么:

mlab.contour3d(x, y, z, my_data_grid)

docs说:

If 4 arrays, (x, y, z, scalars) are passed, the 3 first arrays give the position of the arrows, and the last the scalar value.

什么是“箭头”？我还没有找到任何示例，当我尝试用我的数据集调用它时出现段错误，因此无法测试。

编辑:现在我明白了 mlab 期望 x、y 和 z 的格式，并且我能够让它工作。然而，并没有箭矢!我假设这是文档中的错误...

Answer 1

与其说是文档中的错误，不如说是描述功能的一种看似别扭的方式。来自同一个文档，contour3d:

Plots iso-surfaces for a 3D volume of data supplied as arguments

据说(加粗我的):

The x, y and z arrays are then supposed to have been generated by numpy.mgrid, in other words, they are 3D arrays, with positions lying on a 3D orthogonal and regularly spaced grid with nearest neighbor in space matching nearest neighbor in the array. The function builds a scalar field assuming the points are regularly spaced.

“箭头”似乎有点笨拙，表示 x、y 和 z 是 `

3D arrays, with positions lying on a 3D orthogonal and regularly spaced grid

具有“构建标量场”作为等值面的功能，有效地“连接点(位置)”。