mlpack-3.4.2/html/confusion__matrix_8hpp_source.html

 #ifndef MLPACK_CORE_DATA_CONFUSION_MATRIX_HPP

 #define MLPACK_CORE_DATA_CONFUSION_MATRIX_HPP


 #include <mlpack/prereqs.hpp>


 namespace mlpack {

 namespace data {


 template<typename eT>

 void ConfusionMatrix(const arma::Row<size_t> predictors,

                      const arma::Row<size_t> responses,

                      arma::Mat<eT>& output,

                      const size_t numClasses);


 } // namespace data

 } // namespace mlpack


 // Include implementation.

 #include "confusion_matrix_impl.hpp"


 #endif

prereqs.hpp
The core includes that mlpack expects; standard C++ includes and Armadillo.

mlpack::data::ConfusionMatrix
void ConfusionMatrix(const arma::Row< size_t > predictors, const arma::Row< size_t > responses, arma::Mat< eT > &output, const size_t numClasses)
A confusion matrix is a summary of prediction results on a classification problem.