File content as of revision 1:18e8ead6f188:

#include "mbed.h"
#include "fixed18.hpp"


//assert
void assert(int flag){
    if( flag){
        printf("error has happend\n\r");
    }    
}

Fix18 step_function(Fix18 x)
{
    if (0 < x.to_double())
    {
        return Fix18(1.0);
    }
    else
    {
        return Fix18(0.0);
    }
}

Fix18 sigmoid(Fix18 x)
{
    double tmp = 1.0 / (std::exp(-x.to_double()) + 1.0);
    return Fix18(tmp);
}
Fix18 sigmoid_gradient(Fix18 x)
{
    double tmp = (1.0 / (std::exp(-x.to_double()) + 1.0));
    double grad = (1.0 - tmp) * tmp;
    return Fix18(grad);
}

Fix18 relu(Fix18 x)
{
    return (0 < x.to_double()) ? x.to_double() : Fix18(0);
}

Fix18 relu_gradient(Fix18 x)
{
    return (0 < x.to_double())   ? 1: 0;
}

mat::Matrix<Fix18> softmax(mat::Matrix<Fix18> obj)
{
    assert(obj.width * obj.height * obj.channel > 1);
    mat::Matrix<double> obj_double(obj.width, obj.height, obj.channel);
    //copy to double
    for (int i = 0; i < obj.width * obj.height * obj.channel; i++)
    {
        obj_double.data[i] = obj.data[i].to_double();
    }

    if (obj.height == 1 && obj.channel == 1)
    //1D soft max
    {
        mat::Matrix<double> max = obj_double.max(0);
        mat::Matrix<double> off_set = obj_double - max;
        mat::Matrix<double> off_exp = off_set.apply(std::exp);
        mat::Matrix<double> off_exp_sum = off_exp.sum(0);
        mat::Matrix<double> soft_max = off_exp / off_exp_sum;
    }
    else if (obj.height != 1)
    //2D soft max
    {

        mat::Matrix<double> max = obj_double.max(0);
        mat::Matrix<double> off_set = obj_double - max;
        mat::Matrix<double> off_exp = off_set.apply(std::exp);
        mat::Matrix<double> off_exp_sum = off_exp.sum(0);
        mat::Matrix<double> soft_max = off_exp / off_exp_sum;

        mat::Matrix<Fix18> soft_max_fix18(soft_max.width, soft_max.height, soft_max.channel);
        for (int copy_i = 0; copy_i < (soft_max.width * soft_max.height * soft_max.channel); copy_i++)
        {
            soft_max_fix18.data[copy_i] = soft_max.data[copy_i];
        }
        return soft_max_fix18;
    }
    else
    {
        std::cout << "error" << std::endl;
    }
    //
}

double cross_entropy_error(mat::Matrix<Fix18> y, mat::Matrix<Fix18> t)
{
    assert(y.width == t.width && y.height == t.height && y.channel == t.channel);

    double delta = 1.0 / 10000000;
    mat::Matrix<double> tmp_y(y.width, y.height, y.channel);
    for (int i = 0; i < (y.width * y.height * y.channel); i++)
    {
        tmp_y.data[i] = y.data[i].to_double();
    }

    mat::Matrix<double> tmp_t(t.width, t.height, t.channel);
    for (int i = 0; i < (t.width * t.height * t.channel); i++)
    {
        tmp_t.data[i] = t.data[i].to_double();
    }

    mat::Matrix<double> result(t.width, t.height, t.channel);
    for (int i = 0; i < (y.width * y.height * y.channel); i++)
    {
        result.data[i] = tmp_y.data[i] * std::log(tmp_t.data[i] + delta);
    }
    double sum = -result.sum(0).data[0];
}