vmec_jax.boundary

Boundary coefficient handling.

VMEC input files specify boundary Fourier coefficients in arrays:

• rbc(n,m), rbs(n,m)

• zbc(n,m), zbs(n,m)

where the boundary is expanded in helical harmonics

R(θ,ζ) = Σ_{m,n} [ rbc(n,m) cos(mθ - nζ) + rbs(n,m) sin(mθ - nζ) ] Z(θ,ζ) = Σ_{m,n} [ zbc(n,m) cos(mθ - nζ) + zbs(n,m) sin(mθ - nζ) ]

This module provides helpers to map the sparse namelist assignments to dense coefficient vectors aligned with a ModeTable.

Functions

boundary_apply_vmec_m1_constraint(boundary, ...)	Apply VMEC's internal m=1 boundary constraint and return helical coeffs.
boundary_aspect_ratio(boundary, basis)	Compute aspect ratio from boundary coefficients using a precomputed basis.
boundary_aspect_ratio_from_static(boundary, ...)	Compute aspect ratio from boundary coefficients using a VMEC static config.
boundary_from_indata(indata, modes, *[, ...])	Build dense boundary coefficient vectors aligned with modes.
boundary_from_input_convention(boundary, ...)	Convert raw input-convention boundary coefficients to solver convention.
boundary_input_from_indata(indata, modes)	Build dense boundary coefficients in the raw input convention.
boundary_undo_vmec_m1_constraint(boundary, ...)	Undo VMEC's internal m=1 boundary constraint and return helical coeffs.

Classes

BoundaryCoeffs(R_cos, R_sin, Z_cos, Z_sin)
BoundaryInternalCoeffs(rbcc, rbss, rbcs, ...)	VMEC internal boundary coefficients (cos/sin of u and v).