Installation

NuSA requires Python 3.10 or newer.

Standard installation

Install the current release from PyPI:

pip install nusa

The default package includes the finite-element models, elements, plotting, reporting, and meshio for reading triangular mesh files.

The historical nusa[mesh] extra remains accepted as a compatibility alias, but meshio is installed by default and the extra is no longer necessary.

Gmsh for mesh generation

Generating meshes from geometry with nusa.mesh.Modeler requires the external Gmsh executable. Gmsh is not a Python dependency of NuSA and is not installed by pip install nusa.

After installing Gmsh, verify that the executable is visible to NuSA:

gmsh --version

If that command works, Modeler.generate_mesh() should be able to find the same executable on PATH.

Windows

Three practical options are:

install Gmsh into the same Python environment with pip:
```
python -m pip install gmsh
gmsh --version
```
This route was validated with the NuSA 0.4.0 Windows release checks and keeps the Gmsh launcher in the same virtual environment as NuSA;
install a precompiled Gmsh application from the official Gmsh downloads and add its executable directory to PATH;

install the conda-forge package:

conda install -c conda-forge gmsh
gmsh --version

Some conda installations expose Gmsh through gmsh.bat or gmsh.cmd. NuSA detects these Windows launchers and runs them through cmd.exe.

If Gmsh is installed inside a Conda environment, its launcher may depend on that environment’s Python installation. Activating an unrelated venv can therefore make gmsh --version fail even though Gmsh is installed. In that case, use Gmsh from the same Conda environment as NuSA, install a standalone Gmsh executable, or invoke the Conda environment explicitly (for example, conda run -n <env> gmsh --version).

macOS

The official Gmsh binaries can be used directly. Homebrew users can install the command-line application with:

brew install gmsh
gmsh --version

Linux

Use the package supplied by your distribution or an official Gmsh binary. On Debian/Ubuntu systems, for example:

sudo apt-get update
sudo apt-get install gmsh
gmsh --version

Google Colab

Colab runs on an Ubuntu-based environment, so Gmsh can be installed in the notebook runtime with apt. See Google Colab for a complete installation, solve, mesh-generation, and post-processing walkthrough.

The Gmsh installation is specific to the current Colab runtime and must be repeated when a new runtime is created.

Custom executable location

If Gmsh is installed but is not on PATH, pass its executable explicitly:

nodes, elements = modeler.generate_mesh(
    gmsh_executable="/path/to/gmsh"
)

Development version

Install the current develop branch directly from GitHub:

pip install "nusa @ git+https://github.com/JorgeDeLosSantos/nusa.git@develop"

For contributor/development work:

git clone https://github.com/JorgeDeLosSantos/nusa.git
cd nusa
git checkout develop
python -m pip install -e ".[test]"
python -m pytest