numcore-scicomp 0.1.1

C++ scientific computing library with Python bindings (pybind11)

NumCore

NumCore is a lightweight scientific computing library written in modern C++ with Python bindings powered by pybind11.

It implements core numerical methods from scratch, including custom vector/matrix classes, linear algebra routines, ODE solvers, and optimization algorithms. The package is designed as both a usable numerical library and a learning-focused implementation of fundamental scientific computing algorithms.

Install package: numcore-scicomp
Python import name: numcore

---

Features

Matrix and Vector Core

• Custom Vector and Matrix classes
• Operator overloading for natural arithmetic syntax
• Shape and bounds validation
• NumPy interoperability through .numpy()
• Python bindings for direct use from Python

Linear Algebra

• Matrix-vector multiplication
• Linear system solving
• Determinant computation
• Matrix inverse
• Least-squares solver
• LU decomposition with partial pivoting

ODE Solvers

• Forward Euler method
• Classical fourth-order Runge-Kutta method, RK4
• Adaptive Dormand-Prince RK45 solver

Optimization

• Gradient Descent
• Adam optimizer
• Newton's method with numerical Hessian
• BFGS with Armijo line search

---

Installation

Install from PyPI

pip install numcore-scicomp

Then use it in Python as:

import numcore as nc

Install from source

git clone https://github.com/ChaitanyaK07/NumCore---Scientific-Computing-Library.git
cd NumCore---Scientific-Computing-Library

python -m pip install .

For development:

python -m pip install -e .

---

Quick Start

import numcore as nc

v = nc.Vector([3.0, 4.0])
print(v.norm())   # 5.0

---

Python Examples

Vector operations

import numcore as nc

x = nc.Vector([1.0, 2.0, 3.0])

print(x.norm())      # 3.741657...
print(x.dot(x))      # 14.0
print((2.0 * x)[1])  # 4.0

Matrix operations

import numcore as nc

A = nc.Matrix(2, 2, [1.0, 2.0,
                     3.0, 4.0])

B = A @ A

print(B[(0, 0)])      # 7.0
print(B[(1, 1)])      # 22.0
print(A.T().numpy())  # convert to NumPy array

Solve a linear system

import numcore as nc

A = nc.Matrix(3, 3, [
    2.0,  1.0, -1.0,
   -3.0, -1.0,  2.0,
   -2.0,  1.0,  2.0,
])

b = nc.Vector([8.0, -11.0, -3.0])

x = nc.linalg.solve(A, b)

print(x.numpy())  # approximately [2.0, 3.0, -1.0]

ODE solving with RK4

import numcore as nc

def harmonic_oscillator(t, y):
    return nc.Vector([y[1], -y[0]])

sol = nc.ode.rk4(
    harmonic_oscillator,
    0.0,
    6.28,
    nc.Vector([1.0, 0.0]),
    0.01,
)

t = sol.t_array()
y = sol.y_array()

print(t.shape)
print(y.shape)

Optimization with BFGS

import numcore as nc

def rosenbrock(v):
    x = v[0]
    y = v[1]
    return (1.0 - x) ** 2 + 100.0 * (y - x * x) ** 2

def rosenbrock_grad(v):
    x = v[0]
    y = v[1]
    return nc.Vector([
        -2.0 * (1.0 - x) - 400.0 * x * (y - x * x),
        200.0 * (y - x * x),
    ])

res = nc.optim.bfgs(
    rosenbrock,
    rosenbrock_grad,
    nc.Vector([0.0, 0.0]),
)

print(res.x[0], res.x[1])      # approximately 1.0, 1.0
print(res.converged)
print(res.iterations)

---

C++ Usage

NumCore can also be used directly as a C++ header-based library.

Example:

#include <iostream>
#include "NumCore/vector.hpp"
#include "NumCore/matrix.hpp"
#include "NumCore/linalg.hpp"

int main() {
    Vector v({3.0, 4.0});
    std::cout << v.norm() << std::endl;

    Matrix A(2, 2, {2.0, 1.0,
                    5.0, 7.0});

    Vector b({11.0, 13.0});
    Vector x = linalg::solve(A, b);

    std::cout << x[0] << " " << x[1] << std::endl;
}

Compile with:

g++ main.cpp -I include -std=c++17 -o main

---

Building from Source

Python package build

python -m pip install .

Manual CMake build

If CMake cannot find pybind11, pass the pybind11 CMake directory explicitly.

Windows PowerShell

$pybind11_DIR = python -m pybind11 --cmakedir

cmake -S . -B build -Dpybind11_DIR="$pybind11_DIR"
cmake --build build --config Release

Run C++ tests:

.\build\Release\tests_cpp.exe

Linux/macOS

pybind11_DIR=$(python -m pybind11 --cmakedir)

cmake -S . -B build -Dpybind11_DIR="$pybind11_DIR" -DCMAKE_BUILD_TYPE=Release
cmake --build build

Run C++ tests:

./build/tests_cpp

---

Running Tests

Python tests

python -m pytest tests/tests_python.py -q

C++ tests

Windows:

.\build\Release\tests_cpp.exe

Linux/macOS:

./build/tests_cpp

---

Project Structure

NumCore/
├── include/
│   └── NumCore/
│       ├── NumCore.hpp
│       ├── vector.hpp
│       ├── matrix.hpp
│       ├── linalg.hpp
│       ├── ode.hpp
│       └── optim.hpp
├── python/
│   ├── bindings.cpp
│   └── numcore/
│       └── __init__.py
├── tests/
│   ├── tests_cpp.cpp
│   └── tests_python.py
├── CMakeLists.txt
├── pyproject.toml
└── README.md

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Algorithms Implemented

Category	Algorithm	Notes
Matrix/Vector	Core arithmetic	Operator overloading and validation
Linear Algebra	Matrix-vector multiplication	C++ implementation exposed to Python
Linear Algebra	Linear solve	LU-based solve with pivoting
Linear Algebra	Determinant	Uses elimination/LU-style logic
Linear Algebra	Matrix inverse	Solves against identity basis
Linear Algebra	Least squares	Normal-equation based implementation
ODE	Euler	Fixed-step first-order method
ODE	RK4	Fixed-step fourth-order Runge-Kutta
ODE	RK45	Adaptive Dormand-Prince method
Optimization	Gradient Descent	User-supplied objective and gradient
Optimization	Adam	Adaptive first/second moment optimizer
Optimization	Newton	Numerical Hessian with regularization
Optimization	BFGS	Quasi-Newton inverse-Hessian update

---

Notes

NumCore is implemented from scratch for clarity and educational value. It is not intended to replace mature high-performance numerical libraries such as NumPy, SciPy, Eigen, BLAS, or LAPACK for large-scale production workloads.

For small examples, learning, experimentation, and understanding how numerical algorithms are built internally, NumCore provides a compact C++/Python implementation.

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Roadmap

• More decomposition methods, including QR and Cholesky
• Sparse matrix support
• Conjugate Gradient and iterative solvers
• More robust benchmarking suite
• Prebuilt wheels for more Python versions and operating systems
• Expanded documentation and examples

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License

Add a license file before public production use. Recommended options for open-source numerical libraries include MIT, BSD-3-Clause, or Apache-2.0.