9fc4afb611
Port pke_params, pke_th_rhs, pke_linearize, and all five controllers to Julia. sim_sanity.jl reproduces the MATLAB main.m operation-mode scenario (100%->80% Q_sg step) and matches final state to 3 decimals across n, T_f, T_avg, T_cold, u. reach_operation.jl is a stub: ReachabilityAnalysis.jl (LGG09, GLGM06, BFFPSV18) numerically explodes on the raw stiff system — envelopes of 1e14 K to 1e37 K instead of the known-tight 0.03 K. Almost certainly a state-scaling issue: precursors C_i ~ 1e5, temperatures ~ 300, eigvals span 5000x. Diagonal scaling + retry is planned; left for the next pass since the hand-rolled MATLAB reach already discharges the operation-mode obligation. Project.toml pins OrdinaryDiffEq >= 6.111 (the one that precompiled cleanly on first instantiate). Manifest gitignored. Hacker-Split: Julia path open, reach side needs a scaling pass. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Julia port
Parallel implementation of the plant model (../plant-model/) in Julia,
intended as an eventual landing spot for reachability if we outgrow the
MATLAB / hand-rolled tooling.
Status
src/pke_params.jl,src/pke_th_rhs.jl,src/pke_linearize.jl— functional, match MATLAB term-for-term.controllers/controllers.jl— all five modes ported (null, shutdown, heatup, operation, scram). LQR factory included via MatrixEquations.jl.scripts/sim_sanity.jl— closed-loop simulation matches MATLAB to 3 decimals on the 100% → 80%Q_sgstep. ✅ passing.scripts/reach_operation.jl— ❌ stub. ReachabilityAnalysis.jl algorithms blow up on this stiff, badly-conditioned system. See the file header for diagnosis and planned fix (state rescaling).
When to prefer Julia over MATLAB
Today: nowhere. The sanity path exists so we don't regret the eventual port.
Once the reach scaling is resolved:
- Nonlinear reach for the P controller in operation mode (CORA / JuliaReach territory where MATLAB's linearization doesn't suffice).
- Heatup reach with its time-varying reference.
- Parametric studies where MATLAB license fees / CI friction matter.
Running
cd julia-port
julia --project=. -e 'using Pkg; Pkg.instantiate()'
julia --project=. scripts/sim_sanity.jl
First run will precompile the dependency stack (OrdinaryDiffEq, ReachabilityAnalysis, LazySets — a few minutes).