gctl_ai/lib/dnn/olayer.h
2025-02-09 21:26:19 +08:00

89 lines
4.0 KiB
C++

/********************************************************
* ██████╗ ██████╗████████╗██╗
* ██╔════╝ ██╔════╝╚══██╔══╝██║
* ██║ ███╗██║ ██║ ██║
* ██║ ██║██║ ██║ ██║
* ╚██████╔╝╚██████╗ ██║ ███████╗
* ╚═════╝ ╚═════╝ ╚═╝ ╚══════╝
* Geophysical Computational Tools & Library (GCTL)
*
* Copyright (c) 2022 Yi Zhang (yizhang-geo@zju.edu.cn)
*
* GCTL is distributed under a dual licensing scheme. You can redistribute
* it and/or modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, either version 2
* of the License, or (at your option) any later version. You should have
* received a copy of the GNU Lesser General Public License along with this
* program. If not, see <http://www.gnu.org/licenses/>.
*
* If the terms and conditions of the LGPL v.2. would prevent you from using
* the GCTL, please consider the option to obtain a commercial license for a
* fee. These licenses are offered by the GCTL's original author. As a rule,
* licenses are provided "as-is", unlimited in time for a one time fee. Please
* send corresponding requests to: yizhang-geo@zju.edu.cn. Please do not forget
* to include some description of your company and the realm of its activities.
* Also add information on how to contact you by electronic and paper mail.
******************************************************/
#ifndef _GCTL_DNN_OLAYER_H
#define _GCTL_DNN_OLAYER_H
#include "gctl/core.h"
#include "gctl/algorithms.h"
namespace gctl
{
enum olayer_type_e
{
RegressionMSE,
MultiClassEntropy,
BinaryClassEntropy,
};
class dnn_olayer
{
public:
dnn_olayer();
virtual ~dnn_olayer();
// The derivative of the input of this layer, which is also the derivative
// of the output of previous layer
const matrix<double> &backward_propagation_data();
// Check the format of target data, e.g. in classification problems the
// target data should be binary (either 0 or 1)
virtual void check_target_data(const matrix<double> &target);
// Another type of target data where each element is a class label
// This version may not be sensible for regression tasks, so by default
// we raise an exception
virtual void check_target_data(const array<int> &target);
// A combination of the forward stage and the back-propagation stage for the output layer
// The computed derivative of the input should be stored in this layer, and can be retrieved by
// the backward_propagation_data() function
virtual void evaluation(const matrix<double> &prev_layer_data, const matrix<double> &target) = 0;
// Another type of target data where each element is a class label
// This version may not be sensible for regression tasks, so by default
// we raise an exception
virtual void evaluation(const matrix<double> &prev_layer_data, const array<int> &target);
// Return the loss function value after the evaluation
// This function can be assumed to be called after evaluate(), so that it can make use of the
// intermediate result to save some computation
virtual double loss_value() const = 0;
// Return the output layer name. It is used to export the NN model.
virtual std::string get_output_name() const = 0;
// Return the output layer type. It is used to export the NN model.
virtual olayer_type_e get_output_type() const = 0;
protected:
matrix<double> der_in_; // Derivative of the input of this layer
// Note that input of this layer is also the output of previous layer
};
}
#endif // _GCTL_DNN_OLAYER_H