tensorflow_dnn_interface.py

#!/usr/bin/env python3
 
 
 
import os
import json
import tempfile
import numpy as np
import tensorflow as tf
import pandas
 
from basf2_mva_python_interface.tensorflow import State
 
from dft import binning
 
from dft import tensorflow_dnn_model as tfm
from dft.TfData import TfDataBasf2, TfDataBasf2Stub
 
 
def get_tensorflow_model(number_of_features, parameters):
    """
    generates the tensorflow model
    :param int number_of_features: number of features is handled separately
    :param dictionary parameters: additional parameters passed to tensorflow_dnn_model.DefaultModel
    :return:
    """
 
    layers = parameters.get('layers', None)
    wd_coeffs = parameters.get('wd_coeffs', [])
 
    lr_dec_rate = parameters.get('lr_dec_rate', 1 / (1 + 2e-7)**1.2e5)
    lr_init = parameters.get('lr_init', .05)
    mom_init = parameters.get('mom_init', .9)
    min_epochs = parameters.get('min_epochs', 300)
    max_epochs = parameters.get('max_epochs', 400)
    stop_epochs = parameters.get('stop_epochs', 10)
 
    if layers is None:
        layers = [['h0', 'tanh', number_of_features, 300, .0001, 1.0 / np.sqrt(300)],
                  ['h1', 'tanh', 300, 300, .0001, 1.0 / np.sqrt(300)],
                  ['h2', 'tanh', 300, 300, .0001, 1.0 / np.sqrt(300)],
                  ['h3', 'tanh', 300, 300, .0001, 1.0 / np.sqrt(300)],
                  ['h4', 'tanh', 300, 300, .0001, 1.0 / np.sqrt(300)],
                  ['h5', 'tanh', 300, 300, .0001, 1.0 / np.sqrt(300)],
                  ['h6', 'tanh', 300, 300, .0001, 1.0 / np.sqrt(300)],
                  ['h7', 'tanh', 300, 300, .0001, 1.0 / np.sqrt(300)],
                  ['y', 'sigmoid', 300, 1, .0001, 0.002 * 1.0 / np.sqrt(300)]]
    else:
        layers[0][2] = number_of_features
 
    # None disables usage of wd_coeffs
    if wd_coeffs is not None and not wd_coeffs:
        wd_coeffs = [2e-5 for _ in layers]
 
    mlp = tfm.MultilayerPerceptron.from_list(layers)
    model = tfm.DefaultModel(mlp, lr_dec_rate=lr_dec_rate, lr_init=lr_init, mom_init=mom_init, wd_coeffs=wd_coeffs,
                             min_epochs=min_epochs, max_epochs=max_epochs, stop_epochs=stop_epochs)
    return model
 
 
def get_model(number_of_features, number_of_spectators, number_of_events, training_fraction, parameters):
    """
    specifies the and configures the tensorflow model
    :param number_of_features:
    :param number_of_spectators:
    :param number_of_events:
    :param training_fraction:
    :param parameters: as dictionary encoded json object
    :return: State obj
    """
 
    # get all parameters, if they are not available, use default values
    if parameters is None:
        parameters = {}
    else:
        if not isinstance(parameters, dict):
            raise TypeError('parameters must be a dictionary')
 
    cuda_mask = parameters.get('cuda_visible_devices', '3')
    tensorboard_dir = parameters.get('tensorboard_dir', None)
 
    batch_size = parameters.get('batch_size', 100)
    seed = parameters.get('seed', None)
 
    # postprocessing parameters, from dictionary
    transform_to_probability = parameters.get('transform_to_probability', False)
 
    # set random state
    if seed:
        print('Seed: ', seed)
        tf.set_random_seed(seed)
 
    # mask cuda devices
    os.environ['CUDA_VISIBLE_DEVICES'] = cuda_mask
    gpus = tf.config.list_physical_devices('GPU')
    if gpus:
        for gpu in gpus:
            tf.config.experimental.set_memory_growth(gpu, True)
 
    # using a stub data set since there is no data available at this state
    stub_data_set = TfDataBasf2Stub(batch_size, number_of_features, number_of_events, training_fraction)
 
    # set saving file name, unfortunately this is already required in partial_fit
    save_dir = tempfile.TemporaryDirectory()
    save_name = os.path.join(save_dir.name, 'mymodel')
 
    model = get_tensorflow_model(number_of_features, parameters)
    training = tfm.Trainer(model, stub_data_set, tensorboard_dir, save_name)
 
    state = State(model)
 
    # training object is required in partial fit
    state.training = training
    state.batch_size = batch_size
    state.save_dir = save_dir
 
    state.transform_to_probability = transform_to_probability
 
    # save parameters
    saved_parameters = parameters.copy()
    saved_parameters['number_of_features'] = number_of_features
    state.parameters = json.dumps(saved_parameters)
    state.seed = seed
    return state
 
 
def apply(state, X):
    """
    modified apply function
    """
 
    binning.transform_ndarray(X, state.binning_parameters)
    chunk_size = 1000000
    if len(X) > chunk_size:
        results = list()
        for i in range(0, len(X), chunk_size):
            results.append(state.model(X).numpy().flatten())
        r = np.concatenate(results).flatten()
    else:
        r = state.model(X).numpy().flatten()
    if state.transform_to_probability:
        binning.transform_array_to_sf(r, state.sig_back_tuple, signal_fraction=.5)
 
    return np.require(r, dtype=np.float32, requirements=['A', 'W', 'C', 'O'])
 
 
def load(obj):
    """
    Load Tensorflow estimator into state
    """
    # tensorflow operations
    gpus = tf.config.list_physical_devices('GPU')
    if gpus:
        for gpu in gpus:
            tf.config.experimental.set_memory_growth(gpu, True)
 
    parameters = json.loads(obj[0])
 
    number_of_features = parameters.pop('number_of_features')
 
    class DataStub:
        """
        simple stub obj
        """
        feature_number = number_of_features
        batches = 1
 
    model = get_tensorflow_model(number_of_features, parameters)
    model.initialize(DataStub())
 
    # tensorflow is a moving target, file loading and saving of mid-level api changes rapidly. so we use the legacy here
    with tempfile.TemporaryDirectory() as path:
        with open(os.path.join(path, obj[1] + '.data-00000-of-00001'), 'w+b') as file1, open(
                os.path.join(path, obj[1] + '.index'), 'w+b') as file2:
            file1.write(bytes(obj[2]))
            file2.write(bytes(obj[3]))
 
        checkpoint = tf.train.Checkpoint(model)
        checkpoint.restore(os.path.join(path, obj[1]))
 
    state = State(model)
    # preprocessing parameters
    state.binning_parameters = obj[4]
 
    # postprocessing transform to probability, if pdf was sampled during training
    state.transform_to_probability = obj[5]
    state.sig_back_tuple = obj[6]
 
    seed = obj[7]
    print('Deep FlavorTagger loading... Training seed: ', seed)
 
    return state
 
 
def begin_fit(state, Xtest, Stest, ytest, wtest, nBatches):
    """
    use test sets for monitoring
    """
    # TODO: split this set to define an independent test set for transformations to probability
    state.Xvalid = Xtest[:len(Xtest) // 2]
    state.yvalid = ytest[:len(ytest) // 2]
 
    state.Xtest = Xtest[len(Xtest) // 2:]
    state.ytest = ytest[len(ytest) // 2:]
 
    return state
 
 
def partial_fit(state, X, S, y, w, epoch, batch):
    """
    returns fractions of training and testing dataset, also uses weights
    :param X: unprocessed training dataset
    :param Xtest: unprocessed validation dataset
    :return: bool, True == continue, False == stop iterations
    """
 
    # the epochs and batches are handled internally by the Trainer. This is all done within 1 external epoch and 1 external batch.
    if epoch > 0 or batch > 0:
        raise RuntimeError
 
    # preprocessing
    state.binning_parameters = binning.get_ndarray_binning_parameters(X)
 
    binning.transform_ndarray(X, state.binning_parameters)
    binning.transform_ndarray(state.Xvalid, state.binning_parameters)
 
    if np.any(np.isnan(X)):
        raise ValueError('NaN values in Dataset. Preprocessing transformations failed.')
 
    # replace stub dataset
    data_set = TfDataBasf2(X, y, state.Xvalid, state.yvalid, state.batch_size, seed=state.seed)
 
    state.training.data_set = data_set
 
    # start training
    state.training.train_model()
 
    return False
 
 
def end_fit(state):
    """
    save the trained model
    :param state:
    :return:
    """
    filename = state.training.save_name
    # postfix -2 is needed (current state gets postfix -1)
    with open(filename + '-2.data-00000-of-00001', 'rb') as file1, open(filename + '-2.index', 'rb') as file2:
        data1 = file1.read()
        data2 = file2.read()
    binning_parameters = state.binning_parameters
 
    # transform to probability has to be saved since state object has to return untransformed network output
    transform_to_probability = state.transform_to_probability
    state.transform_to_probability = False
 
    # sample pdfs of trained model on test_dataset, return test df
    y_hat = state.model(state.Xtest).numpy().flatten()
    test_df = pandas.DataFrame.from_dict({'y': state.ytest.reshape(-1), 'y_hat': y_hat.reshape(-1)})
    (sig_pdf, back_pdf) = binning.get_signal_background_pdf(test_df)
    seed = state.seed
    parameters = state.parameters
    del state
    return [parameters, os.path.basename(filename), data1, data2, binning_parameters, transform_to_probability,
            (sig_pdf, back_pdf), seed]