This is a free (GPL) electromagnetic simulation software compatable with NEC-2. It has been rewritten from the ground up.

Nec2++ consists of a library that can be called from C++, C, and python, and so it can incorporated into other projects like GUI tools and automatic antenna optimization systems.

There is also an executable necpp that can read antenna description files (like the original). Nec2++ is developed on Debian linux, but will work on a variety of other operating systems.

• NEC-2 syntax compatable.
• C, C++, and Python libraries included. Ideal for antenna optimization.
• Large designs can be simulated with tens of thousands of elements (to the limit of 64-bit address space)
• Geometry error detection. Throws exceptions if wires intersect or lie too close to one another.
• Simulate in different media (for example antennas in seawater) by modifying the dielectric properties.
• Uses Eigen 5.0.1 (bundled) for fast linear algebra — no external BLAS/LAPACK needed.

If you use nec2++, please cite it as follows:

Timothy C.A. Molteno, ''NEC2++: An NEC-2 compatible Numerical Electromagnetics Code'', Electronics Technical Reports No. 2014-3, ISSN 1172-496X, October 2014.

Online documentation built form the source code is available at http://tmolteno.github.io/necpp/. A guide to using nec2++ from python.

nec2++ builds with CMake (≥ 3.16) and a C++17 compiler — Eigen is bundled, so there are no external dependencies. The short version:

cmake -B build && cmake --build build -j4 && sudo cmake --install build

Full instructions (debug builds, cross-compiling for Windows/macOS/WASM, packaging, and using the library via find_package or pkg-config) are in INSTALL.md.

From the repository root:

cmake -B build && cmake --build build ./build/tests/nec2++_tests -s

Or via CTest:

cd build && ctest

The testharness/ directory compares nec2++ output against the nec2c (C) and FORTRAN reference engines. See testharness/README.md for setup and usage.

• http://tmolteno.github.io/necpp/ Documentation
• https://github.com/lncgomz/UCNEC Java-Based GUI project
• https://github.com/tmolteno/python-necpp/ Python packages
• https://github.com/rcnlee/necpp.jl Julia wrapper for the python packages