fullseye

ode_flow_states — MATH dynsys op

使い方

Integrate a named vector field — the trajectory, with the order you paid for.

Explicit Runge-Kutta on one of the named systems (lorenz, rossler, harmonic, linear). method="rk4" is the classical 4th-order step; method="euler" is there as a control group — the same picture comes out of both, and only the error tells them apart.

For a linear system the classical RK4 polynomial update matrix is formed once and reused. It is deliberately not the matrix exponential: the expected fifth-order one-step difference remains observable.

★Why the field is a name, not a function: the typed ledger registers inputs by sort and the chain fuzzer builds arguments from data, so a callable can never be reached from there. A name (or, for linear, the matrix itself in params) keeps every op in this family reachable from the ledger.

★Why this earns its place: for system="linear" the exact solution is expm(A t) x0, so the error is known in closed form — and halving dt divides it by 16, which is what “4th order” means. A drawing of an attractor cannot be checked; this can.

Parameters

system : str One of DYNSYS_SYSTEMS. params : floats or None System parameters (defaults in DYNSYS_SYSTEMS). For linear this is the matrix A in row-major order (n*n numbers). x0 : floats or None Initial state (default: a point on the attractor / unit first coordinate). t_end, dt : float Integration window and step. t_end / dt must stay under 4,000,000. method : “rk4” | “euler”

Returns a states table: t (S,) and one (S,) column per state, named x0, x1, … .

Raises ValueError: unknown system or method; wrong parameter count; non-finite input; dt not positive; a step count over the cap; a trajectory that left float range (the field diverged — reported, never silently clipped).

HALCON: no operator.

ファミリ共通の入力契約(fail-closed)

mathops の全 op は入力を検証してから計算する(黙って通さない):

詳しい使い方ガイド

参考(サンプルデータ・文献)

実行できる例(この op を実際に呼ぶ検証済みサンプル)

型が繋がる次の op(table を入力に取れる)

dynsys_poincare_section · dwt_inverse · chebyshev_eval_nd

同カテゴリ(dynsys)

ode_vector_field_grid · dynsys_poincare_section · dynsys_lyapunov_spectrum · dynsys_bifurcation_map · dynsys_correlation_dimension


Provenance: mathops.py — MATH operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.