/* NiuTrans.Tensor - an open-source tensor library
* Copyright (C) 2017, Natural Language Processing Lab, Northestern University.
* All rights reserved.
*
* 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.
*/

/*
* $Created by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-04-24
*/

#ifndef __NORMALIZE_H__
#define __NORMALIZE_H__

#include "../../XTensor.h"

namespace nts { // namespace nts(NiuTrans.Tensor)

/*
normalized the data with normal distribution. 
For an input x, y = a * (x-mean)/sqrt(variance+\epsilon) + b
where a and b are the scalar and bias respectively, and \epsilon is the adjustment parameter.
*/
void _Normalize(const XTensor * input, XTensor * output, int dim, const XTensor * mean, const XTensor * var, const XTensor * a, const XTensor * b, DTYPE epsilon);

/*
normalized the data with normal distribution (do it on site)
keep the result in the input tenosr and return nothing
For an input x, x = a * (x-mean)/sqrt(variance+\epsilon) + b
where a and b are the scalar and bias respectively, and \epsilon is the adjustment parameter.
*/
void _NormalizeMe(XTensor * input, int dim, const XTensor * mean, const XTensor * var, const XTensor * a, const XTensor * b, DTYPE epsilon);

/*
normalized the data with normal distribution (return a XTensor structure)
make a new tensor to keep the result and return it 
For an input x, y = a * (x-mean)/sqrt(variance+\epsilon) + b
where a and b are the scalar and bias respectively, and \epsilon is the adjustment parameter.
*/
XTensor Normalize(const XTensor &input, int dim, const XTensor &mean, const XTensor &var, const XTensor &a, const XTensor &b, DTYPE epsilon);

} // namespace nts(NiuTrans.Tensor)

#endif // __NORMALIZE_H__
