desc.coils.SplineXYZCoil.compute_magnetic_field
- SplineXYZCoil.compute_magnetic_field(coords, params=None, basis='rpz', source_grid=None)Source
Compute magnetic field at a set of points.
The coil current may be overridden by including current in the params dictionary.
- Parameters:
coords (array-like shape(n,3)) – Nodes to evaluate field at in [R,phi,Z] or [X,Y,Z] coordinates.
params (dict, optional) – Parameters to pass to Curve.
basis ({"rpz", "xyz"}) – Basis for input coordinates and returned magnetic field.
source_grid (Grid, int or None, optional) – Grid used to discretize coil. If an integer, uses that many equally spaced points. Should NOT include endpoint at 2pi.
- Returns:
field (ndarray, shape(n,3)) – magnetic field at specified points, in either rpz or xyz coordinates
Notes
Discretizes the coil into straight segments between grid points, and uses the Hanson-Hirshman expression for exact field from a straight segment. Convergence is approximately quadratic in the number of coil points.