# tree_d_3d.kernels.fmm_evaluate.fmm_evaluate_metal

*module*

The Metal version (Apple-silicon GPU, float32) of the ``fmm_evaluate`` kernel.

``fmm_evaluate_pyccel.py`` next to this file is the CPU version with the same
arguments. One thread per leaf (far field) and per pair (exact near field) adds into
zeroed atomic float32 delta arrays (see :mod:`tree_d_3d.kernels._metal_atomic`); the host
adds those to ``phi`` and ``field`` in float64. An unsoftened coincident charge sets
``status[0]`` to a failing particle + 1 (the first failing thread's; the other
threads still run). See :mod:`tree_d_3d.kernels._metal` for the float32 caveats.

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

## tree_d_3d.kernels.fmm_evaluate.fmm_evaluate_metal.fmm_evaluate

*function*

```python
def fmm_evaluate(pos: Array, charge: Array, perm: Array, node_count: int, node_center: Array, node_start: Array, node_end: Array, node_child: Array, local_re: Array, local_im: Array, pairs: Array, count: int, softening: float, with_potential: int, phi: Array, field: Array, status: Array) -> None
```

Far field from the leaf local expansions plus the exact mutual near field.

[View source](https://github.com/max-models/tree-d-3d/blob/devel/src/tree_d_3d/kernels/fmm_evaluate/fmm_evaluate_metal.py#L102-L148)