desc.vmec.VMECIO.compute_theta_coords
- classmethod VMECIO.compute_theta_coords(lmns, xm, xn, s, theta_star, zeta, si=None)Source
Find theta such that theta + lambda(theta) == theta_star.
- Parameters:
lmns (array-like) – fourier coefficients for lambda
xm (array-like) – poloidal mode numbers
xn (array-like) – toroidal mode numbers
s (array-like) – desired radial coordinates (normalized toroidal magnetic flux)
theta_star (array-like) – desired straight field-line poloidal angles (PEST/VMEC-like flux coordinates)
zeta (array-like) – desired toroidal angles (toroidal coordinate phi)
si (ndarray) – values of radial coordinates where lmns are defined. Defaults to linearly spaced on half grid between (0,1)
- Returns:
theta (ndarray) – theta such that theta + lambda(theta) == theta_star