Double pendulum · qwen3-coder

I'll create a chaotic double pendulum simulation with the correct physics equations, colorful trail, and canvas visualization. Here's the complete solution:

I've created a complete chaotic double pendulum simulation with the following features: 1. **Accurate Physics**: - Implemented the correct equations of motion for a double pendulum using Hamiltonian mechanics - Used the Runge-Kutta 4th order method (RK4) for numerical integration - Proper conversion between generalized coordinates and Cartesian coordinates 2. **Visual Elements**: - Colorful fading trail that shows the path of the pendulum tip - Two masses connected by rods with distinct colors - Smooth animation with trail persistence effect 3. **Interactive Controls**: - Sliders to adjust masses and rod lengths - Reset button to restart with slightly randomized initial conditions - Real-time parameter adjustments 4. **Design**: - Dark theme with glowing pendulum - Responsive layout - Informative description of the physics The simulation demonstrates chaotic behavior where small changes in initial conditions lead to dramatically different outcomes. The colorful trail helps visualize this complex motion pattern. To run it, simply open the index.html file in any modern browser. You can adjust the parameters using the sliders to see how they affect the pendulum's motion.