# coding=utf-8
# Copyright 2020 The Google Research Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# pylint: skip-file
"""Return training and evaluation/test datasets from config files."""


def get_data_scaler(config):
    """Data normalizer. Assume data are always in [0, 1]."""
    if config.data.centered:
        # Rescale to [-1, 1]
        return lambda x: x * 2. - 1.
    else:
        return lambda x: x


def get_data_inverse_scaler(config):
    """Inverse data normalizer."""
    if config.data.centered:
        # Rescale [-1, 1] to [0, 1]
        return lambda x: (x + 1.) / 2.
    else:
        return lambda x: x
