Wire Cell Toolkit Configuration

What is here

This repository holds a reference set of Wire Cell Toolkit configuration files, largely in the form of Jsonnet.

The files at top level are general utilities are effort will be kept to maintain their stability.

Sub-directories can be expected to evolve (and disappear). Effort will be made to keep what is there current with the contemporaneous C++ code.

For more information on configuration see the WCT configuration manual as well as news posts tagged with config.

Contents overview

This describes what is available. Be wary is may not always be up to date with the reality on the ground.

General support files

Files at top level provide general support and utilities. Primarily there is the file:

• ./wirecell.jsonnet

This holds a Jsonnet version of the WCT system of units (which is essentially identical to CLHEP’s). It also includes a number of Jsonnet functions to form some common configuration data structures.

• ./vector.jsonnet

This holds some functions to assist in doing vector arithmetic in Jsonnet.

• ./pgraph.jsonnet

This holds functions to support building a processing graph for use by the Pgrapher WCT app component. Some details are here.

Pgrapher Modules

Although there are several WCT app components, currently the most powerful and flexible is Pgrapher. It’s configuration is based on building a graph of nodes and with the help of pgraph.jsonnet it is possible to factor many of the possible graphs into common a set of subgraphs. This allows a full configuration to be constructed at various levels of detail culminating on a simple high-level aggregation of nodes which is typically in the form of a simple linear pipeline.

A factored collection of Pgrapher configuration is available under ./pgrapher/. See it’s README for more info.

Obsolete

Configuration can become obsolete when the C++ changes or when new paradigms of configuration organization are adopted. That configuration may be moved to ./obsolete/ for some time before being dropped from the tip of the master branch.

Tests

There may be other Jsonnet files found in the /test/ sub-directories of the various WCT packages.

Running the configuration tests is done through the files under test/. They rely on a simple ad-hoc test harness. All tests can be run from the top-level wire-cell source directory after a build like:

./cfg/test/test_all.sh

A single test can be run like:

./cfg/test/test_one.sh <testname>

Each test has a test_<testname>.jsonnet file.

ls cfg/test/test_*.jsonnet

These main JSonnet files are typically composed of some chunks reused by the various different tests. The chunks are named like cfg_*.jsonnet. The body of each main test_<testname>.jsonnet largely consists of the data flow graph definition for the TbbFlow Wire Cell application object.

See also https://github.com/wirecell/wire-cell-tests.

JQ tricks

The jq tool is like grep for JSON. Here are some useful tricks to operate on a mongo big JSON file.

WCT JSON Config Files

Find an element in the configuration sequence by type

$ jq '.[]| select(.type|contains("Drifter"))' wct.json