📈 equation_painter

Open Source Flutter Package by junayedahamed

A powerful, interactive, and performant Flutter package for visualizing multiple mathematical equations simultaneously with beautiful animations and a fully customizable coordinate system.

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✨ Features

• ✅ New: Interactive Panning & Zooming: Drag to pan and pinch to zoom around the coordinate system!
• ✅ New: Polar Coordinate Support: Visualize equations in polar form r = f(theta).
• ✅ New: Inequality Visualization: Shading for regions like y >= x or x^2 + y^2 <= 25.
• ✅ New: Tap & Hover to Inspect: Tap or hover on any curve to see the exact (x, y) or (r, theta) coordinates.
• ✅ Robust Equation Parsing: Type equations like x^2 + y^2 - 100, sin(2x) - y, pow(x,2) * atan2(y,x) directly. It supports implicit multiplication (2x), constants (pi, e), unit +/- and ~20 built-in math functions.
• ✅ Coordinate Labels: Show dynamic numbers along the axis to measure your functions.
• ✅ Customizable Unit Scale: By default, each grid square represents 100 units, but you can adjust this to your specific needs.
• ✅ Configurable Units: Define how many units each grid square represents.
• ✅ Dynamic Animations: Beautiful radial, sequential, linearX, or linearY draw mechanics.
• ✅ High Performance: Highly optimized utilizing Float32List, drawRawPoints and Marching Squares evaluation to preserve silky smooth 60fps framerates.

📸 Screenshots

Multiple Curves with Custom Styles and Complex Functions

Sin wave with radial animation

Heart curve

Cos wave with value inspection

Inequality Visualization

🚀 Getting Started

Add the package to your pubspec.yaml:

dependencies:
  equation_painter: ^0.1.0+7

💡 Usage

EquationPainter(
  equations: [
    EquationConfig(
      function: (x, y) => x * x + y * y - 25,
      color: Colors.indigoAccent,
      strokeWidth: 4,
    ),
  ],
  unitsPerSquare: 10,
  interactive: true,
  showGrid: true,
  onPointTapped: (x, y, config) {
    print("Tapped at ($x, $y)");
  },
)

🧮 Enhanced Equation Parsing

You can parse string-based equations directly using EquationParser. It's highly tolerant!

Supported Syntax

• Variables: x, y
• Constants: pi (pi), e (e)
• Operators: +, -, *, /, ^ (power)
• Implicit Multiplication: 2x, 3(x+y), x(y-1)
• Functions:
  • Trigonometric: sin, cos, tan, asin, acos, atan, atan2(y, x)
  • Logarithmic & Exponential: log/ln (natural), log2, log10, exp
  • Rounding & Absolute: abs, ceil, floor, round, sign
  • Miscellaneous: sqrt, cbrt (cube root), hypot(a, b), pow(base, exp), min(a, b), max(a, b)

final userEquation = "tan(20x) - tan(15y) + sin(xy) - 10";
final mathFunction = EquationParser.parseOrNull(userEquation); // Returns null if invalid 

if (mathFunction != null) {
  EquationConfig(
    function: mathFunction,
    color: Colors.pinkAccent,
  )
}

❄️ Advanced Features

• Customizable Grid Styles: Support for logarithmic scales, dashed lines, and custom colors.
• Export to Image/SVG: Easily save your visualized equations as high-quality images or SVGs.

🔭 Future Upgrade Ideas

• 🚀 3D Equation Visualization: Support for plotting z = f(x, y) in a 3D coordinate system.
• 🚀 Parametric Equation Support: Plot curves defined by equations like x = f(t), y = g(t).
• 🚀 Live Equation Editor: A built-in UI component to type and preview equations in real-time.
• 🚀 Data Series Plotting: Ability to plot discrete data points (scatter plots) alongside continuous equations.
• 🚀 Legend & Tooltips: Add customizable legends and more detailed information tooltips for complex graphs.

⭐ Support the Project

If you like this project, please give it a ⭐ on GitHub and share it with your friends! It really helps me out and motivates me to keep improving it. Thank you for your support! 🙏

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🤝 Contributing

Contributions are welcome! Feel free to open issues or submit pull requests.

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Crafted with ❤️ for Mathematicians and Developers.