Python API Installation

stepss is a Python interface to the RAMSES dynamic simulator and the Helios AC power-flow engine, enabling users to define test cases, run simulations, extract results, and perform post-processing, all within Python scripts or Jupyter notebooks.

stepss supports Windows, Linux, and macOS, for both dynamic simulation and the bundled Helios power-flow engine, and integrates with standard scientific Python libraries (NumPy, SciPy, Matplotlib).

Installation

Install stepss and all recommended dependencies via pip:

pip install jupyter ipython stepss

Required dependencies (matplotlib, scipy, numpy) are installed automatically.

For a minimal installation (no plotting or notebook support):

pip install stepss

Version numbers

A stepss version is the bundled RAMSES version, optionally followed by a counter: version 3.59 carries RAMSES 3.59. The counter is appended when stepss is released without a new RAMSES behind it, so a 3.59.1 would bundle RAMSES 3.59 as well. A new RAMSES release restarts the sequence with a bare version.

stepss on PyPI starts at 3.59; nothing below that can be installed.

To pin an engine version, pin the matching stepss release:

pip install "stepss~=3.59.0"    # any 3.59.x, all bundling RAMSES 3.59

Check what an installed copy carries:

import stepss
print(stepss.__version__, stepss.__ramses_version__, stepss.__helios_version__)

Linux System Prerequisites

On Linux, the following system libraries must be installed before running stepss:

sudo apt install libopenblas0 libgfortran5 libgomp1

These packages provide:

Package	Purpose
`libopenblas0`	OpenBLAS BLAS/LAPACK routines used by the solver
`libgfortran5`	GNU Fortran runtime required by the Fortran components of RAMSES
`libgomp1`	OpenMP runtime for multi-core parallel execution

On most desktop Linux distributions these are already present. If stepss fails to import with a shared-library error, install the packages above and retry.

macOS System Prerequisites

On macOS (Apple Silicon), install the GNU compiler runtimes and OpenBLAS via Homebrew before running stepss:

brew install gcc openblas

These provide the libgfortran, libgomp, and libopenblas dylibs that the bundled arm64 binaries link against. Intel Macs are not supported.

Optional: Gnuplot for Real-Time Plots

stepss can display observables in real-time during simulation using Gnuplot. This is particularly useful for long simulations to monitor progress.

sudo apt-get install gnuplot-x11

brew install gnuplot

Platform Support

Platform	Library	Notes
Windows	`ramses.dll`	Primary platform, full support
Linux	`ramses.so`	Full support (requires the system libraries above)
macOS	`ramses.so`	Apple Silicon (arm64) only; requires the Homebrew runtimes above

Next Steps

API Reference, Full API documentation
Examples, Practical usage examples