desc.equilibrium.Equilibrium.compute_theta_coords

Equilibrium.compute_theta_coords(flux_coords, L_lmn=None, tol=1e-06, maxiter=20)

Find geometric theta for given straight field line theta.

Parameters:

• flux_coords (ndarray, shape(k,3)) – 2d array of flux coordinates [rho,theta*,zeta]. Each row is a different coordinate.

• L_lmn (ndarray) – spectral coefficients for lambda. Defaults to eq.L_lmn

• tol (float) – Stopping tolerance.

• maxiter (int > 0) – maximum number of Newton iterations

Returns:

coords (ndarray, shape(k,3)) – coordinates [rho,theta,zeta]. If Newton method doesn’t converge for a given coordinate nan will be returned for those values