relational_network.py

#!/usr/bin/env python3
 
 
 
# This example serves as a basic example of implementing Relational networks into basf2 with tensorflow.
# As a toy example it will try to tell if 2 out of multiple lines are hitting each other in three dimensional space.
# Relevant Paper: https://arxiv.org/abs/1706.01427
# If you want to try out relational networks to your problem, feel free to import the two classes in your code.
 
from basf2_mva_python_interface.contrib_keras import State
 
 
from keras.layers import Dense, GlobalAveragePooling1D, Input
from keras.layers.core import Reshape
from keras.models import Model
from keras.optimizers import Adam
from keras.losses import binary_crossentropy
from keras.activations import sigmoid, tanh
from keras.callbacks import Callback, EarlyStopping
import numpy as np
 
from basf2_mva_extensions.keras_relational import Relations
 
 
def get_model(number_of_features, number_of_spectators, number_of_events, training_fraction, parameters):
    """
    Building keras model
    """
 
    input = Input(shape=(number_of_features,))
    net = input
 
    if parameters['use_relations']:
        net = Reshape((number_of_features // 6, 6))(net)
        net = Relations(number_features=parameters['number_features'])(net)
        # average over all permutations
        net = GlobalAveragePooling1D()(net)
    else:
        for i in range(6):
            net = Dense(units=2 * number_of_features, activation=tanh)(net)
 
    output = Dense(units=1, activation=sigmoid)(net)
 
    state = State(Model(input, output), custom_objects={'Relations': Relations})
 
    state.model.compile(optimizer=Adam(lr=0.001), loss=binary_crossentropy, metrics=['accuracy'])
    state.model.summary()
 
    return state
 
 
def begin_fit(state, Xtest, Stest, ytest, wtest):
    """
    Returns just the state object
    """
    state.Xtest = Xtest
    state.ytest = ytest
 
    return state
 
 
def partial_fit(state, X, S, y, w, epoch):
    """
    Do the fit
    """
    class TestCallback(Callback):
        """
        Print small summary.
        Class has to inherit from abstract Callback class
        """
 
        def on_epoch_end(self, epoch, logs=None):
            """
            Print summary at the end of epoch.
            For other possibilities look at the abstract Callback class.
            """
            loss, acc = state.model.evaluate(state.Xtest, state.ytest, verbose=0, batch_size=1000)
            loss2, acc2 = state.model.evaluate(X[:10000], y[:10000], verbose=0, batch_size=1000)
            print('\nTesting loss: {}, acc: {}'.format(loss, acc))
            print('Training loss: {}, acc: {}'.format(loss2, acc2))
 
    state.model.fit(X, y, batch_size=100, epochs=100, validation_data=(state.Xtest, state.ytest),
                    callbacks=[TestCallback(), EarlyStopping(monitor='val_loss')])
    return False
 
 
if __name__ == "__main__":
    import os
    import pandas
    from root_pandas import to_root
    import tempfile
    import json
 
    import basf2_mva
    import basf2_mva_util
    from basf2 import conditions
    # NOTE: do not use testing payloads in production! Any results obtained like this WILL NOT BE PUBLISHED
    conditions.testing_payloads = [
        'localdb/database.txt'
    ]
 
    # ##############Building Data samples ###########################
    # This is  a dataset for testing relational nets.
    # It consists of number_total_lines lines in 3 dimensional space.
    # Each line has 6 variables.
    # In apprx. half of the cases, two lines are hitting each other.
    # This is considered a signal event.
    # Training results differs from the number of total lines.
 
    variables = []
    # try using 10 and 20 lines and see what happens
    number_total_lines = 5
    # Names for the training data set
    for i in range(number_total_lines):
        variables += ['px_' + str(i), 'py_' + str(i), 'pz_' + str(i), 'dx_' + str(i), 'dy_' + str(i),
                      'dz_' + str(i)]
    # Number of events in training and test root file.
    number_of_events = 1000000
 
    def build_signal_event():
        """Building two lines which are hitting each other"""
        p_vec1, p_vec2 = np.random.normal(size=3), np.random.normal(size=3)
        v_cross = np.random.normal(size=3)
        epsilon1, epsilon2 = (np.random.rand() * 2 - 1) / 10, (np.random.rand() * 2 - 1) / 10
        v_vec1 = v_cross + (p_vec1 * epsilon1)
        v_vec2 = v_cross + (p_vec2 * epsilon2)
        return np.concatenate([p_vec1, v_vec1]), np.concatenate([p_vec2, v_vec2])
 
    # This path will delete itself with all data in it after end of program.
    with tempfile.TemporaryDirectory() as path:
        for filename in ['train.root', 'test.root']:
            print('Building ' + filename)
            # Use random numbers to build all training and spectator variables.
            data = np.random.normal(size=[number_of_events, number_total_lines * 6])
            target = np.zeros([number_of_events], dtype=bool)
 
            # Overwrite for half of the variables some lines so that they are hitting each other.
            # Write them also at the end for the spectators.
            for index, sample in enumerate(data):
                if np.random.rand() > 0.5:
                    target[index] = True
                    i1, i2 = int(np.random.rand() * number_total_lines), int(np.random.rand() * (number_total_lines - 1))
                    i2 = (i1 + i2) % number_total_lines
                    track1, track2 = build_signal_event()
                    data[index, i1 * 6:(i1 + 1) * 6] = track1
                    data[index, i2 * 6:(i2 + 1) * 6] = track2
 
            # Saving all variables in root files
            dic = {}
            for i, name in enumerate(variables):
                dic.update({name: data[:, i]})
            dic.update({'isSignal': target})
 
            df = pandas.DataFrame(dic, dtype=np.float32)
            to_root(df, os.path.join(path, filename), key='variables')
 
        # ##########################Do Training#################################
        # Do a comparison of different Nets for this task.
 
        general_options = basf2_mva.GeneralOptions()
        general_options.m_datafiles = basf2_mva.vector(os.path.join(path, 'train.root'))
        general_options.m_treename = "variables"
        general_options.m_variables = basf2_mva.vector(*variables)
        general_options.m_target_variable = "isSignal"
 
        specific_options = basf2_mva.PythonOptions()
        specific_options.m_framework = "contrib_keras"
        specific_options.m_steering_file = 'mva/examples/keras/relational_network.py'
        specific_options.m_training_fraction = 0.999
 
        # Train relational Net
        print('Train relational net ')
        general_options.m_identifier = os.path.join(path, 'relation.xml')
        specific_options.m_config = json.dumps({'use_relations': True,
                                                'number_features': 3})
        basf2_mva.teacher(general_options, specific_options)
 
        # Train normal feed forward Net:
        print('Train feed forward net')
        general_options.m_identifier = os.path.join(path, 'feed_forward.xml')
        specific_options.m_config = json.dumps({'use_relations': False})
        basf2_mva.teacher(general_options, specific_options)
 
        # ########################Compare Results####################################
        method1 = basf2_mva_util.Method(os.path.join(path, 'relation.xml'))
        method2 = basf2_mva_util.Method(os.path.join(path, 'feed_forward.xml'))
 
        test_data = basf2_mva.vector(os.path.join(path, 'test.root'))
 
        print('Apply relational net')
        p1, t1 = method1.apply_expert(test_data, general_options.m_treename)
        print('Apply feed forward net')
        p2, t2 = method2.apply_expert(test_data, general_options.m_treename)
 
        print('Relational Net AUC: ', basf2_mva_util.calculate_roc_auc(p1, t1))
        print('Feed Forward Net AUC: ', basf2_mva_util.calculate_roc_auc(p2, t2))