Input parameter files

What ASPECT computes is driven by two things:

• The models implemented in ASPECT. This includes the geometries, the material laws, or the initial conditions currently supported. Which of these models are currently implemented is discussed below; Extending and contributing discusses in great detail the process of implementing additional models.

• The run-time parameters of the selected model. For example, you could select a model that prescribes constant coefficients throughout the domain from all the material models currently implemented; you could then select appropriate values for all of these constants. Both of these selections happen from a parameter file that is read at run time and whose name is specified on the command line. (See also Overview.)

In this section, let us give an overview of the structure of these input parameter files. Specific parameters, their default values, and allowed values for these parameters are documented on our parameter website, and the Parameter Documentation chapter of this documentation.

When writing or modifying parameter files we strongly recommend to use Visual Studio Code with the ASPECT extension. This extension enables syntax highlighting, auto-completion, and includes the documentation for all ASPECT parameters, thus greatly simplifying the process of writing ASPECT parameter files. Take note that by default the extension will make use of the input parameters of the latest ASPECT release. If you are using a different ASPECT version you can change the settings of the extension.

• The structure of parameter files
• Categories of parameters
• How to write Function expressions in parameter files
  • Syntax
  • Help with MuParser syntax
  • Lazy expressions
• Compatibility of input files with newer ASPECT versions