| // Copyright (C) 2020 Davis E. King ([email protected]) | |
| // License: Boost Software License See LICENSE.txt for the full license. | |
| namespace dlib | |
| { | |
| // ---------------------------------------------------------------------------------------- | |
| template <typename label_type> | |
| struct weighted_label | |
| { | |
| weighted_label() | |
| {} | |
| weighted_label(label_type label, float weight = 1.f) | |
| : label(label), weight(weight) | |
| {} | |
| label_type label{}; | |
| float weight = 1.f; | |
| }; | |
| // ---------------------------------------------------------------------------------------- | |
| inline double log1pexp(double x) | |
| { | |
| using std::exp; | |
| using namespace std; // Do this instead of using std::log1p because some compilers | |
| // error out otherwise (E.g. gcc 4.9 in cygwin) | |
| if (x <= -37) | |
| return exp(x); | |
| else if (-37 < x && x <= 18) | |
| return log1p(exp(x)); | |
| else if (18 < x && x <= 33.3) | |
| return x + exp(-x); | |
| else | |
| return x; | |
| } | |
| // ---------------------------------------------------------------------------------------- | |
| template <typename T> | |
| T safe_log(T input, T epsilon = 1e-10) | |
| { | |
| // Prevent trying to calculate the logarithm of a very small number (let alone zero) | |
| return std::log(std::max(input, epsilon)); | |
| } | |
| // ---------------------------------------------------------------------------------------- | |
| static size_t tensor_index( | |
| const tensor& t, | |
| const long sample, | |
| const long k, | |
| const long r, | |
| const long c | |
| ) | |
| { | |
| return ((sample * t.k() + k) * t.nr() + r) * t.nc() + c; | |
| } | |
| // ---------------------------------------------------------------------------------------- | |
| } | |