ytree.analysis.analysis_pipeline.AnalysisPipeline.add_operation

AnalysisPipeline.add_operation(function, *args, always_do=False, preprocess_function=None, **kwargs)

Add an operation to the AnalysisPipeline.

An operation is a function that minimally takes in a target object and performs some actions on or with it. This function may alter the object’s state, attach attributes, write out data, etc. Operations are used to create a pipeline of actions performed in sequence on a list of objects, such as all halos in a merger tree. The function can, optionally, return True or False to act as a filter, determining if the rest of the pipeline should be carried out (if True) or if the pipeline should stop and move on to the next object (if False).

Parameters:

• function (callable) – The function to be called for each node/halo.

• *args (positional arguments) – Any additional positional arguments to be provided to the funciton.

• always_do (optional, bool) – If True, always perform this operation even if a prior filter has returned False. This can be used to add house cleaning operations that should always be run. Default: False

• preprocess_function (optional, callable) – A function to be run once at the start of analysis. This can be used to perform any necessary startup tasks prior to running the pipeline. The function provided must accept no arguments. Default: None

• **kwargs (keyword arguments) – Any keyword arguments to be provided to the function.