Vorticity confinement support

[Xayah-Hina]

Hi~ I noticed that field.curl for 3D is not yet supported, would this function to be supported in future version? thx~

# file '_field_math.py', line 647
def curl(field: Field, at='corner'):
    """
    Computes the finite-difference curl of the give 2D `StaggeredGrid`.

    Args:
        field: `Field`
        at: Either `center` or `face`.
    """
    assert 'vector' in field.shape, f"curl requires a vector field but got {field}"
    assert field.spatial_rank in (2, 3), "curl is only defined in 2 and 3 spatial dimensions."
    if field.is_grid and field.is_staggered and field.spatial_rank == 2 and at == 'corner':
......
    elif field.is_grid and field.is_centered and field.spatial_rank == 2 and at == 'corner':
...... 
    raise NotImplementedError("Only 2D curl at corner currently supported")

[holl-]

Hi @Xayah-Hina Do you need this for staggered or centered grids, and sampled at the corners or centers?

[Xayah-Hina]

Hi @Xayah-Hina Do you need this for staggered or centered grids, and sampled at the corners or centers?

Yes for staggered grids(velocity field) and centered grids(force fields). I also want some useful field operations like Helmholtz Decomposition for 3D vector fields. Is that possible to implement? thx~