ml-pid-cbm

Python package for training ML model for particle Identification (Msc thesis) in the CBM experiment.

This package is based on the hipe4ml package.

Installation

To run this project, you need to set up a Conda environment with the required packages. Follow the steps below:

1. Clone the repository:

   git clone https://github.com/julnow/ml-pid-cbm.git
   cd ml-pid-cbm
   

2. Install necessary packages described in the enivornment.yml file to your conda environment, for example:

   conda env update --file environment.yml --name enivornment_name
   

3. As this package is based on the hipe4ml, Mac OS users also are required to install the OpenMP library:

   brew install libomp
   

Run Locally

This package constsits of three main modules.

0. config.json

However, you should first fill all the necessary fields in the config.json The root trees can be e.g., created using ml-tree-plainer package.

{
    "file_names": {
        "training": "/path/to/traing/dataset.root",
        "test": "/path/to/test_validation/dataset.root"
    },
    "var_names": {
        "momentum": "name_of_the_momentum_variable_in_tree"
    },
    "features_for_train": [ "mass2", "dE/dx"],
    "vars_to_draw": ["variable_a","xgb_preds"],
    "cuts": {
        "momentum": {"lower": -12.0, "upper": 12.0},
    },
    "hyper_params": {
        "values": {"n_estimators": 670},(...)
        "ranges": {
            "n_estimators": [300, 1200],(...)
        }
    }
}

If the hyper_params are given explicitly, the model can use them; providing the ranges is necessary for the optimization of hyperparams wiht optuna.

1. train_model

Module for training the XGBoost model.

It should be run with options:

usage: ML_PID_CBM TrainModel [-h] --config CONFIG --momentum MOMENTUM MOMENTUM
                             [--antiparticles] [--hyperparams] [--gpu]
                             [--nworkers NWORKERS]
                             [--printplots | --saveplots] [--usevalidation]

where:

• --config should be the location of the config file, e.g., -c config.json
• --momentum describe lower and upper momentum cut, e.g., -m 0 3
• --antiparticles flag sets used only egative charge, otherwise positive
• --gpu turns on GPU-usage for training
• --nworkers sets number of threads available for the _ThreadPoolExecutor_, e.g., -n 8
• --printplots shows the plots interactively, while the --saveplots saves them in png and pdf format
• --usevalidation uses validation dataset for creating the model output graphs, useful to check during the training if the model performs similarily on the training validation (e.g., created using DCM simulation model) and validation (e.g., creating using URQMD)

2. validate_model

Module for validating a trained XGBoost model.

It should be run with options:

usage: ML_PID_CBM ValidateModel [-h] --config CONFIG --modelname MODELNAME
                                (--probabilitycuts PROBABILITYCUTS PROBABILITYCUTS PROBABILITYCUTS | --evaluateproba EVALUATEPROBA EVALUATEPROBA EVALUATEPROBA)
                                [--nworkers NWORKERS]
                                [--interactive | --automatic AUTOMATIC]

where:

• --config should be the location of the config file, e.g., -c config.json
• --modelname is the name of the folder created during the trainig step containg the model (which will have the same name), e.g., -m model_0_1_positive
• --nworkers sets number of threads available for the _ThreadPoolExecutor_, e.g., -n 8
• Probabilitycuts:
  • --probabilitycuts can be set manually, for respectively PROTONS, KAONS, PIONS in the current implementation, e.g., -p .9 .8 .9
  • --evaluateproba will check probability cuts for each particle from LOWER_VALUE to UPPER_VALUE using N_STEPS, e.g., -e .35 .98 40
• If probabilitycuts where set using --evaluateproba, user have to options:
  • Select them interactively if --interactive provided
  • Apply automatic selection using --automatic, aiming for MINIMAL_PURITY %, e.g., -a 90

The automatic probabilitycut selection alghoritm:

1. Chooses the probability cut with the highest efficiency, if the purity is higher than MINIMAL_PURITY
2. If there is no cut with purity> MINIMAL_PURITY, it will choose the one with the highest purity.

3. validate_multiple_models

Module for merging the results from multiple models into single output and histograms.

It should be run with options:

usage: ML_PID_CBM ValidateMultipleModels [-h] --modelnames MODELNAMES
                                         [MODELNAMES ...] --config CONFIG
                                         [--nworkers NWORKERS]

where:

• --config should be the location of the config file, e.g., -c config.json
• --nworkers sets number of threads available for the _ThreadPoolExecutor_, e.g., -n 8
• --modelnames should be a list of all validated models whose results should be merged, e.g., -m modelA modelB modelC

4. Bash files

For better automation, a bash file can be created for all the steps.

For example, in the bash_training we can define:

#!/bin/bash

eval "$(conda shell.bash hook)"
conda activate env

CONFIG="config.json"
python -u ../../train_model.py -c $CONFIG -p 0 1.6 --saveplots --nworkers 8 --usevalidation  | tee train_bin_0.txt
python -u ../../train_model.py -c $CONFIG -p 1.6 2.3 --saveplots --nworkers 8 --usevalidation  | tee train_bin_1.txt

Later, in the bash_validate:

#!/bin/bash

eval "$(conda shell.bash hook)"
conda activate env

CONFIG="config.json"

#validation of single models
for dir in model_*
    do
        if [[ -d "$dir" ]]; then
            readymodels+="$dir "
            python ../../validate_model.py -c $CONFIG -m $dir -n 8 -e .4 .95 40 -a 90
       fi
done
python ../../validate_multiple_models.py -c $CONFIG -m $readymodels --nworkers 4

which will validate all the models in the directory, and later merge their results.

Documentation

Documentation available here