1) Why Poincaré Maps Matter
Many nonlinear systems evolve in continuous time, yet their long‑term behavior is easiest to compare in a discrete snapshot. A Poincaré map samples the state once per cycle (stroboscopic) or whenever a trajectory crosses a chosen surface (section). The resulting point set exposes periodic orbits, quasiperiodic tori, and chaotic attractors with far less clutter than a full time series.
2) What This Calculator Produces
The calculator integrates the selected model and records intersection points after transients are discarded. It reports the number of accepted points, basic statistics, and a downloadable table for plotting. For stroboscopic maps, the sampling period is T = 2π/ω; for section maps, crossings are detected by a sign change across the plane with linear interpolation to estimate the intersection.
3) Default Models and Typical Ranges
Three common benchmarks are included: the Duffing oscillator, the driven pendulum, and the Rössler flow. Reasonable starting ranges are δ≈0.05–0.3, α≈−1 to 1, β≈0.1–1, γ≈0–0.6 for Duffing; damping b≈0.05–0.5 and drive A≈0–2 for the pendulum; and a=0.2, b=0.2, c≈4–10 for Rössler.
4) Time Step and Accuracy Guidance
Because the map is sensitive to phase, choose dt small enough to resolve the fastest oscillation. A practical rule is dt ≤ T/500 for stroboscopic sampling, then tighten if points smear. For flows like Rössler, dt of 0.001–0.01 often works; if the solver hits max‑steps, reduce the total time or increase max‑steps cautiously to protect performance.
5) Transient Removal and Point Count
Discarding early iterations is essential: many systems need hundreds of cycles to settle onto an attractor. A transient fraction of 20–50% is common. For clear structure, aim for 200–2000 Poincaré points. Too few points can hide period‑doubling; too many points can slow rendering and inflate downloads without adding insight.
6) Reading the Geometry
A single repeating point implies a period‑1 orbit; two or four clustered points indicate period‑doubling. A closed curve suggests quasiperiodicity, while a fractal cloud signals chaos. In section maps, check that crossings are consistently oriented; mixing both directions can mirror the set and complicate interpretation.
7) Parameter Sweeps and Reproducibility
To study bifurcations, sweep one parameter while keeping dt, transient fraction, and sampling rules fixed. Export each run to CSV and plot overlays or bifurcation diagrams in external tools. Record the exact initial conditions and seed settings; small changes can shift the observed set when the dynamics are chaotic.
8) Practical Uses in Physics
Poincaré maps support stability analysis in driven oscillators, beam dynamics, and celestial mechanics. They help identify resonances, locking regions, and transport barriers. In experiments, the same concept appears as stroboscopic imaging or phase‑locked sampling, making the calculator useful for planning measurements and validating simulations.
Summary: Reliable maps come from careful sampling and consistent settings.