vmec_jax.residuals

Force/residual diagnostics.

VMEC reports scalar residual measures (e.g. fsqr/fsqz/fsql) that track how close a state is to satisfying the equilibrium Euler-Lagrange equations.

In vmec_jax we do not yet reproduce VMEC’s full real-space force kernels, but we can provide a useful, differentiable proxy based on the gradient of the total objective. These diagnostics are meant to:

  • support regression tests (consistency across refactors),

  • provide solver stopping criteria beyond just energy decrease,

  • and act as a stepping stone toward full VMEC residue/getfsq parity.

Functions

force_residuals_from_state(state, static, *, ...)

Compute force-like scalar residuals from the total-objective gradient.

Classes

ForceResiduals(fsqr_like, fsqz_like, ...)

Scalar residual diagnostics derived from objective gradients.