Running¶

If you have an aegir clone built with pixi, run any workflow with:

pixi run phlex -c workflows/gun_st.jsonnet

Or drop into a pixi shell first for an interactive session:

pixi shell
phlex -c workflows/gun_st.jsonnet

activate.sh sets PHLEX_PLUGIN_PATH, LD_LIBRARY_PATH, SHIPGEOMETRY_ROOT, SHIPFIELD_ROOT and AEGIR_ROOT automatically in both modes, so you don't need to set a prefix by hand.

If you do not need to modify the source, you can also consume the pre-built aegir package from the prefix.dev/ship-experiment/stable channel. See Installation for that flow.

Workflows¶

Information regarding the simulation to generate is located in the .jsonnet files. The workflows/ folder has examples for the particle gun, Pythia8, fixed-target and file-input setups; ls workflows/ shows them all. Most of them build on the shared blocks in workflows/lib.libsonnet.

Phlex requires every job to name its processing stage. The aegir workflows set stage: 'simulation' at the top level, and each generator source needs the same stage in its own block, because Phlex does not pass the top-level value on to sources. The lib.libsonnet blocks already include it; set both if you write a workflow from scratch.

Generators and Geant4 draw a random seed for each run unless you give one. The seed is logged at startup, so a run can still be reproduced. Workflows that take a seed argument, such as fixed_target_mt.jsonnet, accept it on the command line:

pixi run phlex -c workflows/fixed_target_mt.jsonnet --tla-code seed=12345

Geometry¶

Choose the geometry provider in the geometry block of the workflow.

The built-in test geometry (a tungsten target with silicon scoring planes) needs no setup. gun_st.jsonnet, pythia8_mt.jsonnet and most of the gun workflows use it:

geometry: { cpp: 'geometry_builtin_provider' },

A GeoModel database comes from the Geometry package. The shipgeometry package ships a build_geometry tool but no pre-built database, so generate one before running a GeoModel workflow such as fixed_target_mt.jsonnet:

pixi run build_geometry          # writes ship_geometry.db to the current directory
pixi run phlex -c workflows/fixed_target_mt.jsonnet

geometry: {
      cpp: 'geometry_geomodel_provider',
      db_file: 'ship_geometry.db',
      sensitive_volumes: ['ScoringPlane'],
    }

The provider looks for a bare db_file name in the current directory first, then in $SHIPGEOMETRY_ROOT/share/geometry/.

A GDML file needs an absolute path in gdml_file (see workflows/gun_st_gdml.jsonnet):

geometry: {
      cpp: 'geometry_gdml_provider',
      gdml_file: '/path/to/ship_target_only.gdml',
      sensitive_volumes: ['ScoringPlane'],
    }