/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/* 
 * File:   matutils.hpp
 * Author: jens
 *
 * Created on 21. Januar 2022, 08:28
 */

#ifndef MATUTILS_HPP
#define MATUTILS_HPP

#include "RnnTextHelper.hpp"

#include <math.h>

namespace Matutils
{
	inline void uniform(arma::mat& srcDst, double stdDev=1.0, double mu=0.5)
	{
	#if 0
		for (size_t i=0; i < srcDst.n_rows; i++)
		{
			for (size_t j=0; j < srcDst.n_cols; j++)
			{
				srcDst(i, j) = stdDev*(Noise_Uniform(&m_noise) + mu - 0.5);
			}
		}
	#else
		srcDst = stdDev*(arma::randu(arma::size(srcDst)) + mu - 0.5);
	#endif
	}

	inline arma::mat sample(const arma::mat &src)
	{
		arma::mat rand = src;
		uniform(rand);

	#if 0
		for (size_t i=0; i < src.n_rows; i++)
		{
			for (size_t j=0; j < src.n_cols; j++)
			{
				dst(i, j) = src(i, j) >= dst(i, j);
			}
		}
		return dst;
	#else
		arma::umat res = (src > rand);
		return arma::conv_to<arma::mat>::from(res);

	#endif	
	}
	
	inline arma::mat normalize(const arma::mat& src)
	{
		std::cout << "Normalizing Training Data ..." << std::endl;

		// Dim = 0: Normalize over training all training pattern
		// Dim = 1: Normalize over single training pattern
		double k = 1;
		size_t dim = 0;
		arma::mat mean = arma::mean(src, dim);
		arma::mat stddev = arma::stddev(src, 0, dim);

		arma::mat mean_mat;
		arma::mat std_mat;

		if (dim==0)
		{
			mean_mat = arma::repmat(mean, src.n_rows, 1);
			std_mat = arma::repmat(stddev, src.n_rows, 1);
		}
		else
		{
			mean_mat = arma::repmat(mean, 1, src.n_cols);
			std_mat = arma::repmat(stddev, 1, src.n_cols);
		}

		arma::mat xn = src - mean_mat;
		arma::mat y = xn/(std_mat + 1e-9);
		std::cout << "mean" << "  : " << std::endl << arma::mean(y, dim) << std::endl;
		std::cout << "stddev" << ": " << std::endl << arma::stddev(y, 0, dim) << std::endl;
		return y;
	}

	inline arma::mat char2vec(char c, size_t len)
	{
		arma::mat result = arma::zeros(1, len);
		int idx = RnnTextHelper::ch2idx(c);
		result[idx] = 1;
		
		return result;
	}
	
	inline char vec2char(arma::mat const &vec)
	{
		char result = RnnTextHelper::idx2ch(vec.index_max());
		
		return result;
	}

}

#endif /* MATUTILS_HPP */