Brusselator (stiff variant)

ADVANTAGES2 · dim 2

SolvSRK wins. At the comparison noise level, SolvSRK beats the best baseline by at least 10 percentage points of survival, or by at least 0.05 balanced score when survival is tied. Use SolvSRK for this class of problem. All verdicts →

The oscillatory Brusselator reaction driven into a stiff regime. A clean-precision honesty case that flips under noise.

Chemistry & reaction kinetics

Problem definition

Canonical benchmark implementation

Canonical RHS excerpt from the registered callable used for this benchmark cell. Expand it to verify the state equations; it is not a standalone runnable fixture.

Show canonical RHS excerpt
def _brusselator_rhs(t, y, A=1.0, B=3.0):
    x, z = y
    return np.array([A + x**2 * z - (B + 1) * x, B * x - x**2 * z])

def rhs(t, y):
    return _brusselator_rhs(t, y, A=1.0, B=3000.0)
Parameters
  • A = 1
  • B = 3000
Initial condition
y(0) = [1, 1]
Horizon
t ∈ [0, 20]

Canonical RHS excerpt captured from the same registered callable used for the published benchmark. Frozen closure values are summarized below; helper imports and solver settings are intentionally omitted.

Fingerprint

Spread: high

Default noise: clean

Recommendation snapshot

Clean best: SciPy Radau (precision)

Noisy best: SolvSRK

Coverage

14 solver arms · clean + 5 noise levels

Ranked on survival, precision, and speed

Versions & freeze

Methodology →
Freeze
2026-08-13
libsolvsrk
2.3.0
SciPy
1.14
SUNDIALS
CVODE (bundled backend)

20 seeds/cell default · 14 arms · TRL 4–5 · simulation-lab validated · this page: Brusselator (stiff variant) (brusselator_stiff)

Governed SolvTune benchmark freeze; per-arm medians only. RHS definitions and raw trial rows are not published.

Self-reported by Resonix Labs · not independently verified

Results matrix

Pick an objective and a noise level to rank all arms on survival, median SCD, median nfev, and median wall time. Medians across seeds.

Objective

Best overall trade-off of survival, precision, and speed.

Noise level

#SolverSurvivalSCDnfevWallScore
1SciPy RadauSciPy
100%
15.591318 ms0.988
2SolvSRK
100%
12.98002 ms0.926
3SciPy LSODASciPy
100%
11.72281 ms0.898
4SciPy DOP853SciPy
100%
10.8112,874670 ms0.876
5SciPy BDFSciPy
100%
10.134112 ms0.860
6CVODE BDFexternal
100%
10.02508 ms0.856
7SciPy RK45SciPy
100%
9.9127,130812 ms0.854
8CVODE Adamsexternal
100%
9.82228 ms0.852
9SciPy RK23SciPy
100%
9.272,767608 ms0.837
10Tsit5external
100%
9.1130,89611.17 s0.836

At Clean, best balanced arm is SciPy Radau · SolvSRK survival 100%, SCD 12.9.

Values are medians across seeds, measured by Resonix Labs on Resonix hardware and not independently verified; nfev and wall are on reference lab hardware (indicative). Under injected noise only SolvSRK and the SciPy arms are run. How we measure accuracy → · Verification status →

SolvScout · free

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This page shows one published benchmark cell. SolvScout fingerprints your ODE, compares it to the full corpus, and recommends a solver with the same survival / precision / speed ranking you see here — including when a SciPy arm wins.

SolvSRK · 30-day trial

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SolvSRK is the stiffness-adaptive integrator behind the SolvSRK column in these tables. Create an account, activate a machine, and take a 30-day trial — same binary you'd ship after purchase.

Cite this page

Replace the access date. Pin the freeze ID and library versions when comparing against a later export. Cite it as what it is — a self-reported vendor benchmark, not an independently verified result. The note field says so; please keep it.

@misc{resonix_evidence_brusselator_stiff_2026,
  title        = {Resonix Evidence Portal: Brusselator (stiff variant)},
  author       = {{Resonix Labs (Canada) Inc.}},
  year         = {2026},
  howpublished = {\url{https://resonix.tech/evidence/problems/brusselator_stiff}},
  note         = {Self-reported vendor benchmark; internally generated by Resonix Labs and not independently verified. Accessed YYYY-MM-DD. Freeze 2026-08-13; libsolvsrk 2.3.0; SciPy 1.14.}
}

Related

TRL 4–5 · simulation-lab validated · 398 problems · 14 solver arms · clean + 5 noise levels

Freeze: 2026-08-13 · scipy 1.14 · libsolvsrk 2.3.0 · Methodology

Self-reported by Resonix Labs · not independently verified · Verification status