PPolySim OS

State-Space Phase Portrait

A linear system's whole personality lives in one 2×2 matrix. Change its entries and watch trajectories spiral, decay, or fly apart.

State-Space Phase PortraitLive

Controls

Presets

A linear state-space system ẋ = Ax has a character set by the eigenvalues of A. Negative real parts spiral or decay to the origin (stable); positive parts fly outward; imaginary parts add rotation. The phase portrait reveals it all at a glance. Educational tool.

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Data Inspector

Trace / Det-0.30 / 1.00
Eigenvalues-0.15 ± 0.99j
Classificationstable spiral

Governing equation

Reading this result: Complex eigenvalues with negative real part: trajectories spiral inward, oscillating while decaying to the origin — a stable, ringing system.

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How it works

For ẋ = Ax, the eigenvalues of A classify the behavior: negative real parts give stable nodes or spirals, positive parts give instability, imaginary parts add rotation, and a negative determinant makes a saddle. The phase portrait visualizes every trajectory at once. Educational tool.

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The math, the assumptions, real-world uses, or a code translation — explained for this exact simulation.

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Frequently asked questions

Is this phase portrait simulator tool really free?
Yes. State-Space Phase Portrait runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.