The python-control library currently lacks interactive plotting capabilities that are essential for modern control system analysis and education. While the library provides excellent static root locus plots, users often need to:

• Explore system behavior interactively - Hover over curves to see gain, damping, and frequency values
• Understand parameter relationships - See how changes in gain affect pole locations in real-time
• Enhance learning experience - Provide visual feedback that helps students understand control theory concepts
• Match commercial software capabilities - Bring python-control closer to MATLAB's interactive features

** The problem **
Real-time GUI's can be tricky for high-order polynomials such as a complex root locus plot. I have experience building precomputed lookup tables and implementing more advanced interpolation techniques for smoothing out resolution issues with real-time followers like the one I proposed.

What This Contribution Adds

• Interactive hover functionality with real-time gain, damping ratio, and frequency display
• High-resolution cursor marker (10,000 resolution points) that follows root locus curves
• Catmull-Rom spline interpolation for ultra-smooth movement along curves
• Information box showing current system parameters
• Maintains original plot style - no visual changes to existing functionality

Why it is efficient and novel?
This improvement uses:

• Precomputed gain tables with log-spaced resolution for optimal performance
• Curve-following interpolation that treats each locus as a separate smooth curve
• Spatial indexing for efficient search and interpolation
• 50 interpolation samples per curve segment for maximum smoothness
• User Experience
• Intuitive interaction - hover vs click-based methods
• Ultra-smooth movement - cursor slides like butter along curves
• Real-time feedback - continuous parameter updates
• Educational value - makes control theory more accessible

You can test it through my fork by running:

git clone https://github.com/AndrewTrepagnier/python-control.git
cd python-control
pip install -e .

Then run:

python examples/high_resolution_demo.py

Now you can hover over the curve to see real-time gain changes.

I find this real-time tool very helpful, I hope this helps and is considered for the control package!

The readme is AI generated so I can delete that if needed. Thanks!