# dlib C++ Library - visitors_abstract.h

    // Copyright (C) 2022  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #undef DLIB_DNn_VISITORS_ABSTRACT_H_
    #ifdef DLIB_DNn_VISITORS_ABSTRACT_H_

    #include "input.h"
    #include "layers.h"
    #include "loss.h"

    namespace dlib
    {

    // ----------------------------------------------------------------------------------------

        template <typename net_type>
        void set_all_bn_running_stats_window_sizes (
            const net_type& net,
            unsigned long new_window_size
        );
        /*!
            requires
                - new_window_size > 0
                - net_type is an object of type add_layer, add_loss_layer, add_skip_layer, or
                  add_tag_layer.
            ensures
                - Sets the get_running_stats_window_size() field of all bn_ layers in net to
                  new_window_size.
        !*/

    // ----------------------------------------------------------------------------------------

        template <typename net_type>
        void fuse_layers (
            net_type& net
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_loss_layer, add_skip_layer, or
                  add_tag_layer.
                - net has been properly allocated, that is: count_parameters(net) > 0.
            ensures
                - Disables all the affine_ layers that have a convolution as an input.
                - Updates the convolution weights beneath the affine_ layers to produce the same
                  output as with the affine_ layers enabled.
        !*/

    // ----------------------------------------------------------------------------------------

        template <typename net_type>
        void net_to_xml (
            const net_type& net,
            std::ostream& out
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_loss_layer, add_skip_layer, or
                  add_tag_layer.
                - All layers in the net must provide to_xml() functions.
            ensures
                - Prints the given neural network object as an XML document to the given output
                  stream.
        !*/

        template <typename net_type>
        void net_to_xml (
            const net_type& net,
            const std::string& filename
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_loss_layer, add_skip_layer, or
                  add_tag_layer.
                - All layers in the net must provide to_xml() functions.
            ensures
                - This function is just like the above net_to_xml(), except it writes to a file
                  rather than an ostream.
        !*/

    // ----------------------------------------------------------------------------------------

        template <typename net_type>
        dpoint input_tensor_to_output_tensor(
            const net_type& net,
            dpoint p
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_skip_layer, or add_tag_layer.
                - All layers in the net must provide map_input_to_output() functions.
            ensures
                - Given a dpoint (i.e. a row,column coordinate) in the input tensor given to
                  net, this function returns the corresponding dpoint in the output tensor
                  net.get_output().  This kind of mapping is useful when working with fully
                  convolutional networks as you will often want to know what parts of the
                  output feature maps correspond to what parts of the input.
                - If the network contains skip layers then any layers skipped over by the skip
                  layer are ignored for the purpose of computing this coordinate mapping.  That
                  is, if you walk the network from the output layer to the input layer, where
                  each time you encounter a skip layer you jump to the layer indicated by the
                  skip layer, you will visit exactly the layers in the network involved in the
                  input_tensor_to_output_tensor() calculation. This behavior is useful since it
                  allows you to compute some auxiliary DNN as a separate branch of computation
                  that is separate from the main network's job of running some kind of fully
                  convolutional network over an image.  For instance, you might want to have a
                  branch in your network that computes some global image level
                  summarization/feature.
        !*/

    // ----------------------------------------------------------------------------------------

        template <typename net_type>
        dpoint output_tensor_to_input_tensor(
            const net_type& net,
            dpoint p
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_skip_layer, or add_tag_layer.
                - All layers in the net must provide map_output_to_input() functions.
            ensures
                - This function provides the reverse mapping of input_tensor_to_output_tensor().
                  That is, given a dpoint in net.get_output(), what is the corresponding dpoint
                  in the input tensor?
        !*/

    // ----------------------------------------------------------------------------------------

        template <typename net_type>
        inline size_t count_parameters(
            const net_type& net
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_loss_layer, add_skip_layer, or
                  add_tag_layer.
            ensures
                - Returns the number of allocated parameters in the network. E.g. if the network has not
                  been trained then, since nothing has been allocated yet, it will return 0.
        !*/

    // ----------------------------------------------------------------------------------------

        template<typename net_type>
        void set_all_learning_rate_multipliers(
            net_type& net,
            double learning_rate_multiplier
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_loss_layer, add_skip_layer, or
                  add_tag_layer.
                - learning_rate_multiplier >= 0
            ensures
                - Sets all learning_rate_multipliers and bias_learning_rate_multipliers in net
                  to learning_rate_multiplier.
        !*/

    // ----------------------------------------------------------------------------------------

        template <size_t begin, size_t end, typename net_type>
        void set_learning_rate_multipliers_range(
            net_type& net,
            double learning_rate_multiplier
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_loss_layer, add_skip_layer, or
                  add_tag_layer.
                - learning_rate_multiplier >= 0
                - begin <= end <= net_type::num_layers
            ensures
                - Loops over the layers in the range [begin,end) in net and calls
                  set_learning_rate_multiplier on them with the value of
                  learning_rate_multiplier.
        !*/

    // ----------------------------------------------------------------------------------------

        template <typename net_type>
        void net_to_dot (
            const net_type& net,
            std::ostream& out
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_loss_layer, add_skip_layer, or
                  add_tag_layer.
            ensures
                - Prints the given neural network object as an DOT document to the given output
                  stream.
                - The contents of #out can be used by the dot program from Graphviz to export
                  the network diagram to any supported format.
        !*/

        template <typename net_type>
        void net_to_dot (
            const net_type& net,
            const std::string& filename
        );
        /*!
            requires
                - net_type is an object of type add_layer, add_loss_layer, add_skip_layer, or
                  add_tag_layer.
            ensures
                - This function is just like the above net_to_dot(), except it writes to a file
                  rather than an ostream.
        !*/
    }

    #endif // DLIB_DNn_VISITORS_ABSTRACT_H_