HIPO Output

The hipo format writes standard CLAS12 HIPO4 banks. It is the native output format for the CLAS12 experiment at Jefferson Lab and is directly readable by coatjava and hipo4 tools.

Unlike the built-in formats, HIPO is delivered as a separate plugin that is part of the clas12-systems repository, not the GEMC core.

Installation

The plugin is built and installed with the clas12-systems package. Once installed, point GEMC_PLUGIN_PATH to its location:

export GEMC_PLUGIN_PATH=/path/to/clas12-systems/install/lib
gemc mydetector.yaml

Or declare the path in your YAML:

plugin_path: /path/to/clas12-systems/install/lib

Configuration

gstreamer:
  - format: hipo
    filename: myrun

Produces one .hipo file per worker thread:

myrun_t0.hipo   myrun_t1.hipo   myrun_t2.hipo   ...

Banks written

Each event writes the following standard CLAS12 banks:

The detector banks follow the standard CLAS12 bank definitions from clas12-offline-software/etc/bankdefs/hipo4.

Supported detectors

The plugin maps GEMC detector names to CLAS12 detector IDs and writes the appropriate ADC/TDC banks for each. Supported detectors include: BMT, BST, CND, CTOF, DC, ECAL, FMT, FT_CAL, FT_HODO, FT_TRK, FTOF, HTCC, LTCC, RICH, RTPC, BAND, URWT, ATOF, AHDC, RECOIL, MUCAL, MUVT, MURT, MURH, and the generic FLUX detector.

Verbosity

The plugin registers its own verbosity domain. Set it in YAML or on the command line:

verbosity:
  - hipo: 1     # file open/close messages
  # hipo: 2     # per-event bank details

gemc mydetector.yaml -verbosity.hipo=2

Because definePluginOptions() is called during startup, the hipo domain must be visible to GEMC before option parsing — this happens automatically when GEMC_PLUGIN_PATH or plugin_path is set and the plugin file is found.

Reading HIPO files

With the hipo4 C++ library:

hipo::reader reader;
reader.open("myrun_t0.hipo");
hipo::dictionary factory;
reader.readDictionary(factory);

hipo::bank dc_tdc(factory.getSchema("DC::tdc"));
hipo::event event;

while (reader.next()) {
    reader.read(event);
    event.getStructure(dc_tdc);
    for (int i = 0; i < dc_tdc.getRows(); ++i) {
        int sector = dc_tdc.getInt("sector", i);
        int wire   = dc_tdc.getInt("component", i);
        int tdc    = dc_tdc.getInt("TDC", i);
        printf("sector %d  wire %d  tdc %d\n", sector, wire, tdc);
    }
}

With coatjava (Java / Groovy):

def reader = new HipoDataSource()
reader.open("myrun_t0.hipo")
while (reader.hasEvent()) {
    def event = reader.getNextEvent()
    def dc    = event.getBank("DC::tdc")
    for (int i = 0; i < dc.rows(); i++) {
        println dc.getInt("sector", i)
    }
}