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Double pendulum · gemini-3-flash-preview

Simulate a chaotic double pendulum on a canvas using the correct equations of motion, drawing the arms and a colorful fading trail of the tip.

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transcript · 4 messages
user

Simulate a chaotic double pendulum on a canvas using the correct equations of motion, drawing the arms and a colorful fading trail of the tip.

assistant
thinking
**Developing Pendulum Dynamics**

I'm currently focused on implementing the core physics for the double pendulum. My plan is to integrate the equations of motion directly, ensuring accurate simulation of its chaotic behavior, before moving on to the canvas rendering and visual elements.

**Implementing Pendulum Physics**

I'm deep into deriving the necessary equations of motion for the double pendulum system. My current focus is on accurately implementing these formulas within the simulation, prioritizing robust numerical integration for precision.

write index.html (7565 bytes)
toolResult

Successfully wrote 7565 bytes to index.html

assistant
thinking
**Simulating Chaos**

I'm focusing on refining the chaotic double pendulum simulation. My current work involves ensuring its stability through RK4 sub-stepping and optimizing the rendering of its vibrant, fading trail against a dark backdrop for a single-page web application.

The Chaotic Double Pendulum simulation has been created in a single self-contained `index.html` file. It features: - **Accurate Physics**: Uses the Lagrangian equations of motion for a double pendulum, integrated with the **Runge-Kutta 4th Order (RK4)** method and sub-stepping for high stability and accuracy. - **Dynamic Visuals**: A fading, rainbow-colored trail that tracks the tip of the second pendulum arm, illustrating the chaotic nature of the system's trajectory. - **Interactive UI**: A reset button to restart the simulation with slight random variations, demonstrating how small changes in initial conditions lead to vastly different outcomes. - **High Performance**: Optimized canvas rendering with a dark "neon" aesthetic. You can now open `index.html` in any modern web browser to view the simulation. ```html <!-- index.html is now present in the current directory --> ```

TAKE IT TO CODE

A single self-contained HTML file — copy it and open in any browser, or reuse the prompt with your own pi-agent run.

RUN

modelgemini-3-flash-preview
vendorGoogle
harnesspi-agent
generated2026-07-22

EVALUATION

4/5 working

Double pendulum animates continuously with correct physics-like motion and colorful fading trail; inputs don't visibly add interactivity.

Vision grade · anthropic/claude-sonnet-5

MEASUREMENTS

Raw readings from the capture, not a verdict — the grade above is the only judgement. Percentages are how much of the screen changed; the measure under-reports sparse motion on a dark background.

idle motion3.7%
on click3.4%
on drag3.8%
on wheel1.6%
on enter + space4.2%
on arrow keys3.7%
on w/a/s/d1.4%
frame spread9.4 / 255
console errors0
js errors none

METRICS

runtime31.7s
tokens in5.5k
tokens out3.6k
cached0
cost / run$0.0136