Modules

In NuRadioReco, the process of reconstruction event properties from data is done by modules. In principle, each step of an analysis should be done by a dedicated module. For example, one module applies a filter to the channel spectrum and a different module reconstructs the electric field from that channel afterwards. In the case of simulation studies, modules can also be used to simulate aspects of the detector response, e.g. the efieldToVoltageConverter, which calculates the voltages in the antennas from the electric field at each antenna.

In principle, modules can be arranged in any order, including loops and if/or branching, though some some modules may require others to be run beforehand. For example, using a module to apply a filter to an electric field only makes sense if the field has been reconstructed by another module beforehand. It is even possible to combine several modules into a single module, for example to make a standard reconstruction model, that performs a reconstruction with the default settings deemed best for a given experiment.

Basic Module Structure

Each module consists of four components:

• A constructor to create the module. In a reconstruction, this is usually called to create the modules before looping over all events in the event file.

• The begin method. This is used to specify settings that will not change on an event-by-event basis.

• The run method. This is executed for each event and executes the task that the module was built for.

• The end Method. This is run after the last event was processed for cleanup or to print information on what the module has done.

These methods should all be called in that order, though the begin and end function can be skipped for some modules.

Logging

Please note that this section is specific to NuRadioReco. For NuRadioMC applications one should replace NuRadioReco with NuRadioMC in the following. Then, the module.setup_logger() function should be called with name="NuRadioMC" as a parameter, or name=" " when both NuRadioReco and NuRadioMC modules are used.

Logging in NuRadioReco is handled using the standard Python logging interface. It uses the fact that loggers can inherit handlers from logger created in parent modules. To achieve this behaviour, every module file MODULE.py should initialise a logger using

import logging

logger = logging.getLogger('NuRadioReco.MODULE')

The logger can then be used across the module, and will report using the name given in the getLogger() function.

Then any script using NuRadioReco modules should initialize a general logger with

import logging
from NuRadioReco.utilities.logging import setup_logger
logger = setup_logger()

This initializes a parent logger, which determines the overall logging level that is inherited by all modules. By default the level is set to STATUS (see below), but this can easily be changed by using the level keyword in the setup_logger() function. This allows to turn DEBUG on for all, for example. It is still possible to change the logging level for individual modules as an overwrite. For example, the begin() function of the class MODULE could take parameter setting the logging level:

class MODULE:
    def __init__(self):
        ...

    def begin(self, logging_level=None):
        if logging_level is not None:
            logger.setLevel(logging_level)

Next to the standard logging levels that Python provides, NuRadioReco implements an additional level called STATUS. Its value is defined in NuRadioReco/utilities/logging.py as LOGGING_STATUS. As of February 2024, this value is 25, which is between WARNING and INFO (meaning that it will only be printed if the logging level is set to STATUS, INFO or DEBUG). In order to log a message with the STATUS level, you can use the logger.status() function.

This behaviour is achieved using the addLoggingLevel() function implemented in the NuRadioReco/utilities/logging.py module, which can also be used in custom scripts to add additional logging levels together with corresponding logging method to any logging class (this should also work with custom logging classes).

Another interesting feature of the Python logging module, is the option to add multiple handlers which each output to a different location. Each of these can have a different logging level. For example, if you wanted to only have the WARNING output printed to the console, but at the same time save all the DEBUG statements to a file for later reference, you can initialize the general logger in your script as

import logging
from NuRadioReco.modules.base import module
logger = module.setup_logger(level=logging.WARNING)

f_handler = logging.FileHandler('debug.log')
f_handler.setLevel(logging.DEBUG)
logger.addHandler(f_handler)

The last three lines in the code block above create a handler which will direct log statements to a file called debug.log, configure that handler to take all logging output with level DEBUG or above and finally add that handler to the logger. It also possible to set a custom formatter to this handler, or add more handler to the logger.