//
//  $filename
//  $projectname
//
//  Created by Joshua moerman on $TODAY.
//  Copyright 2010 Joshua Moerman. All rights reserved.
//

#include "Polynomial.hpp"
#include <algorithm>
//#include <iostream>

Polynomial::Polynomial():
		AttractorKernel(3, 0),
		orde(2){

    init();
}

Polynomial::Polynomial(const unsigned int dimension, const unsigned int orde):
		AttractorKernel(dimension, 0),
		orde(orde) {
    init();
}

void Polynomial::init() {
    const unsigned int number = calculateNumberOfParameters();
	reallocParameters(number);
}

// i want to has constexpr, so the ctor can be clean :]
unsigned int Polynomial::calculateNumberOfParameters() {
    double n_coef = orde + 1;
    for (unsigned int i = 2; i <= dimension; i++) {
        n_coef = n_coef*(orde + i)/(i - 1);
    }

    const unsigned int output = (unsigned int) n_coef;
    return output;
}

void Polynomial::operator()() {
	std::swap(vectorNew, vectorOld);

    unsigned int m = 0;
    for ( unsigned int i = 0; i < dimension; i++ ) {

        vectorNew[i] = parameters[m];
        m++;
        recur(i, 0, 1, m);
    }

}

void Polynomial::recur(unsigned int curr_dimension, unsigned int prev_i, unsigned int n, unsigned int& m, double prev_product) {
    double product;
    for (unsigned int i = prev_i; i < dimension; i++) {

        product = prev_product * vectorOld[i];
        vectorNew[curr_dimension] += parameters[m] * product;
        m++;
        if (n < orde) {
            recur(curr_dimension, i, n+1, m, product);
        }
    }
}