Representation of positions of points spaced along field lines.

This takes an array of starting positions on the poloidal plane and then creates 3D coordinates by following the magnetic field from those points. It can be used to hold data describing the shape of elements in a mesh.

The object can be made to correspond to only a fraction of the data in the x3 direction by dividing it into a certain number of subdivisions and choosing one of these.

Public members¶

start_points : SliceCoords

The points on the poloidal surface from which field-line tracing begins. The points are logically arranged in an ND array (although some may be masked).

x3 : npt.NDArray

The x3 positions along the field lines at which to find the points.

trace : FieldTrace

The underlying magnetic field to which the geometry is aligned.

alignments : npt.NDArray

The extent to which projections from each of the starting points follows the field line versus stays fixed at the starting poloidal position. A value of 1 corresponds to it completely following the field line while 0 means it doesn’t follow it at all (the x1 and x2 coordinates are unchanged as moving in the x3 direction). Values in between result in linear interpolation between these two extremes. This array should be of the same or lower dimension as start_points and must be broadcast-compatible with it.

subdivision : int

The index of the segment of the data in the x3-direction that this particular object represents.

num_divisions : int

The number of segments this data is divided into along the x3-direction.

Constructors¶

FieldAlignedPositions(start_points: SliceCoords, x3, ...)

Initialize self. See help(type(self)) for accurate signature.

Special methods¶

__getitem__(idx) → FieldAlignedPositions

Slice the start-points of the data, returning the specificed subset.

__repr__()

Return repr(self).

Methods¶

subdivide(divisions: int) → Iterator[FieldAlignedPositions]

Split the data into the specified number of pieces in x3.