polyfit2d is a lightweight, header-based C++17 library for fitting and evaluating 2D polynomial surfaces using least squares. It's built on top of Eigen for matrix operations and provides a clean, simple interface.

• Fit a polynomial surface of arbitrary degree to 3D data points.
• Efficient least-squares solver using Eigen.
• Easy evaluation of the fitted surface at any (x, y) point.
• Header-only interface.
• MIT licensed and open source.

This project uses CMake for configuration and building.

• Eigen 3.3+
• C++17 compatible compiler

git clone https://github.com/gbowne1/polyfit2d.git
cd polyfit2d
mkdir build && cd build
cmake ..
make
./polyfit2d_tests

Here's a good way to use it

#include <iostream>
#include "polyfit2d/polyfit2d.hpp"

int main() {
    using namespace polyfit2d;

    std::vector<Point3D> points = {
        {0, 0, 1},
        {1, 0, 2},
        {0, 1, 2},
        {1, 1, 3}
    };

    PolynomialSurface surface(1);
    surface.fit(points);

    std::cout << "f(0.5, 0.5) = " << surface.evaluate(0.5, 0.5) << std::endl;

    return 0;
}

This project is licensed under the MIT License — see the LICENSE

Contributions, issues and feature requests are welcome!

• Fork the repository

• Create your feature branch (git checkout -b feature/some-feature)

• Commit your changes (git commit -am 'Add new feature')

• Push to the branch (git push origin feature/some-feature)

• Create a new Pull Request