Installation

This guide covers the installation of STEPSS, including the Java GUI, Visual Studio, and the Intel Fortran compiler.

Note

The Java, Visual Studio, and OneAPI files are not part of STEPSS. They are provided only to ease the installation procedure.

All needed files can be downloaded from the Google Drive folder.

Installing Java

STEPSS comes with a Java-based Graphical User Interface (GUI) that requires a 64-bit Java Runtime Environment, version 11 or later. Any recent JRE or JDK is fine — there is no need to uninstall a Java you already have, as long as it meets that minimum.

1. Check existing installation: Open a Windows Command prompt and enter:

   java -version

   If this reports a 64-bit Java, you are ready — skip to the next section.

2. Install Java (only if the command is not recognised):

   • Download a 64-bit JDK from oracle.com, or from the Google Drive
   • Double-click to install and follow the instructions

3. Associate STEPSS with Java:

   • Right-click on stepss.jar
   • Select “Open with” → “Always use this application”

Installing STEPSS

1. Download stepss.jar from the Google Drive
2. Place it in any convenient location (e.g., your Desktop)
3. Do not uncompress the archive
4. Launch by double-clicking stepss.jar

When launched, STEPSS creates a temporary working folder and copies all needed executables and libraries. To remove STEPSS, simply delete the archive file. It leaves nothing on your computer.

Current version: 3.40

Installing Visual Studio

Tip

This step can be skipped if you do not plan to develop new models for RAMSES using CODEGEN.

The Intel oneAPI compiler requires Microsoft Visual Studio Community 2019 or later (2022 recommended). If you already have a version that meets this requirement, there is no need to uninstall it.

1. Download a Community installer from visualstudio.microsoft.com, or the launcher from the Google Drive: vs_community__e942d3d4864d4a80b72975352289d007.exe
2. Execute by double-clicking
3. During installation, under the “Workloads” view, select “Desktop development with C++“

Installing the Fortran Compiler

Tip

This step can be skipped if you do not plan to develop new models for RAMSES.

STEPSS is compiled with ifx, the Intel oneAPI Fortran compiler. Use a oneAPI release of version 2024.0 or later, which provides ifx.

Caution

The older ifort (“Fortran Compiler Classic”) is deprecated by Intel and is no longer supported. Do not use it.

Two packages need to be installed in order, both free of charge from Intel:

1. Download and install the Intel oneAPI Base Toolkit

2. Download and install the Intel oneAPI HPC Toolkit, which contains the ifx Fortran compiler

   Both are available from Intel’s oneAPI HPC Toolkit download page.

3. Restart your computer

Installing CODEGEN Studio

Tip

This step can be skipped if you do not plan to build user-defined models visually. You can also write DSL files by hand. See User-Defined Models.

CODEGEN Studio is a browser-based visual editor for assembling CODEGEN models using drag-and-drop blocks.

CODEGEN Studio requires Python 3.10 or later.

1. Install from PyPI:

   pip install stepss-cg-studio

2. Launch it:

   cg-studio

3. Open http://localhost:8765 in your browser

To compile models from within the editor, configure the codegen binary path in Settings (gear icon). See the CODEGEN Studio guide for details.

Installing PyRAMSES

For the Python interface to RAMSES, see the PyRAMSES Installation Guide.