default_reltol
Stable constant · Simulation
Tier: stable · Kind: constant · Topic: Simulation
| Julia | TypeScript | Python | Rust | Go |
|---|---|---|---|---|
| not exported | DEFAULT_RELTOL | not exported | DEFAULT_RELTOL | outside profile |
Julia
Julia does not export this constant.
TypeScript
const DEFAULT_RELTOL: 0.0001
Binding default relative tolerance (API_SPEC §5.8) — the bottom of the
§2.2.2 chain, used when neither the caller nor solver.reltol sets one.
Python
Python does not export this constant.
Rust
pub const DEFAULT_RELTOL: f64 = 1e-4;
The canonical default relative tolerance.
All three simulation-capable bindings defaulted differently — Rust 1e-6,
Python scipy’s 1e-3, Julia 1e-4 — so the same document solved with
default options did not produce comparable trajectories. The ruling is to
adopt Julia’s pair, which is what this is; Rust’s own default was two
orders TIGHTER, so aligning loosens it.
These are the defaults for a production run, not for a conformance
assertion. A test that pins a trajectory to a numerical threshold should
pass an explicit reltol/abstol rather than lean on these — that is what
the knobs are for, and it is what the in-tree fixtures do.
Go
Not available in Go. Go is outside the simulation capability profile (Julia, Python, Rust): build an RHS and integrate it; TypeScript and Go are deliberately non-simulating.