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// This original code was written by
//  Onkar Raut
//  Graduate Student,
//  University of North Carolina at Charlotte

#include "precomp.hpp"

void cv::polyfit(const Mat& src_x, const Mat& src_y, Mat& dst, int order)
{
    CV_Assert((src_x.rows>0)&&(src_y.rows>0)&&(src_x.cols==1)&&(src_y.cols==1)
            &&(dst.cols==1)&&(dst.rows==(order+1))&&(order>=1));
    Mat X;
    X = Mat::zeros(src_x.rows, order+1,CV_32FC1);
    Mat copy;
    for(int i = 0; i <=order;i++)
    {
        copy = src_x.clone();
        pow(copy,i,copy);
        Mat M1 = X.col(i);
        copy.col(0).copyTo(M1);
    }
    Mat X_t, X_inv;
    transpose(X,X_t);
    Mat temp = X_t*X;
    Mat temp2;
    invert (temp,temp2);
    Mat temp3 = temp2*X_t;
    Mat W = temp3*src_y;
    W.copyTo(dst);
}