# tree_d_3d.kernels.quadtree_moments.quadtree_moments_pyccel

*module*

The Pyccel version (CPU) of the ``quadtree_moments`` kernel of the Barnes-Hut and FMM solvers.

``quadtree_moments_cuda.cu`` next to this file is the CUDA version (GPU) and ``quadtree_moments_numpy.py`` the
version for machines without Pyccel, all with the same arguments; the folder's
``__init__.py`` declares the kernel (see :mod:`tree_d_3d.kernels`). The flat
quadtree is described in :mod:`tree_d_3d.flat_tree`.

[View source](https://github.com/max-models/tree-d-3d/blob/devel/src/tree_d_3d/kernels/quadtree_moments/quadtree_moments_pyccel.py#L1-L1)

## tree_d_3d.kernels.quadtree_moments.quadtree_moments_pyccel.quadtree_moments

*function*

```python
def quadtree_moments(pos: float[:, :], charge: float[:], perm: int64[:], node_count: int, node_center: float[:, :], node_start: int64[:], node_end: int64[:], node_q: float[:], node_qabs: float[:], node_p: float[:, :], node_s: float[:, :]) -> None
```

Signed moments of every node about its centre; ``node_s`` is xx, xy, yy.

[View source](https://github.com/max-models/tree-d-3d/blob/devel/src/tree_d_3d/kernels/quadtree_moments/quadtree_moments_pyccel.py#L13-L58)