Analysis Module

Analysis

Post-processing and visualization utilities for GPEC simulation outputs.

Submodules

• ForceFreeStates: Plotting functions for DCON-style ideal MHD stability results
• Equilibrium: Plotting functions for equilibrium objects

ForceFreeStates

Post-processing and visualization functions for ForceFreeStates (DCON-style ideal MHD stability) results stored in GPEC HDF5 output files.

plot_eigenmode_summary(h5path; save_path=nothing)

Three-panel summary of the free-boundary energy matrix eigenmodes, analogous to the DCON summary plot produced by OMFIT GPEC.

Panels:

• Top: |eigenvector| vs index for the least stable mode
• Bottom-left: heatmap of |W_t| (eigenvectors) vs mode index
• Bottom-right: |eigenvalue| on log scale vs mode index

Eigenvectors are scaled by χ₁ = 2π ψ₀ × 10⁻³ to match GPEC conventions.

Arguments

• h5path: Path to a GPEC HDF5 output file with vacuum data (vac_flag = true)

Keyword arguments

• save_path: If provided, save the figure to this path (default: nothing)

Returns

A Plots.jl plot object.

plot_mode_displacement(h5path; modes=1:5, save_path=nothing)

Plot Im(ξψ) vs ψN for the least stable eigenmode, showing one curve per requested poloidal mode number m.

Arguments

• h5path: Path to a GPEC HDF5 output file (e.g. "gpec.h5")

Keyword arguments

• modes: Iterable of m values to plot (default: 1:5)
• save_path: If provided, save the figure to this path (default: nothing)

Returns

A Plots.jl plot object.

plot_stability_criterion(h5path; save_path=nothing)

Plot the stability criterion (smallest eigenvalue of W⁻¹, crit) vs ψ_N. A sign change in crit during integration indicates an ideal fixed-boundary instability.

Arguments

• h5path: Path to a GPEC HDF5 output file

Keyword arguments

• save_path: If provided, save the figure to this path (default: nothing)

Returns

A Plots.jl plot object.

Equilibrium

Post-processing and visualization functions for GPEC equilibrium objects.

plot_flux_surfaces(plasma_eq; n_psi=11, n_theta=13)

Plot flux surface contours (constant ψ, blue) and field-line angle contours (constant θ, red) in physical (R, Z) space.

Arguments

• plasma_eq: A GeneralizedPerturbedEquilibrium.Equilibrium.PlasmaEquilibrium object

Keyword arguments

• n_psi: Number of constant-ψ contours to draw (default: 11)
• n_theta: Number of constant-θ contours to draw (default: 13)

Returns

A Plots.jl plot object.