Code snippets

Some code snippets that can be useful.

Print lstchain version used to produce a file

The lstchain version is stored in the file metadata. You can print it with the following command:

In python:

import tables
filename = 'dl1_file.h5'
file = tables.open_file(filename)
print(file.root._v_attrs['LSTCHAIN_VERSION'])

In bash:

h5dump -a /LSTCHAIN_VERSION dl1_file.h5

Note

ctapipe and ctapipe_io_lst versions are also stored in the metadata. You can print them with the same commands, replacing LSTCHAIN_VERSION by CTAPIPE_VERSION or CTAPIPE_IO_LST_VERSION.

Print configuration parameters used by the script/tool

The configuration file used by a given script/tool is stored in the metadata of the output file. Note that the configuration file can contain more parameters than the ones used in a given analysis stage as the same configuration file can be used for several stages.

import tables
import yaml
filename = 'dl1_file.h5'
with tables.open_file(filename) as file:
    config = yaml.safe_load(file.root.dl1.event.telescope.parameters.LST_LSTCam.attrs["config"])
print(config)
# Or for a given parameter section e.g.:
print(config['tailcut_clean_with_pedestal_threshold'])

Print calibration and auxiliary files used by the script/tool

For observed data, the calibration and auxiliary files used to produce DL1 data are stored in the metadata of the DL1 files. You can print them with the following command:

import tables
import yaml
filename = 'dl1_file.h5'
with tables.open_file(filename) as file:
    config = yaml.safe_load(file.root.dl1.event.telescope.monitoring.calibration.attrs["config"])
# Drive log with pointing information
print(config['source_config']['LSTEventSource']['PointingSource'])
# Run summary file with reference timestamps and counters for timestamp calculation
print(config['source_config']['LSTEventSource']['EventTimeCalculator'])
# Calibration files (DRS4 baseline corrections, calibration coefficients, time calibration, etc)
print(config['source_config']['LSTEventSource']['LSTR0Corrections'])
print(config['LSTCalibrationCalculator']['systematic_correction_path'])

All these metadata information can be accessed interactively using ViTables.