#include "precomp.hpp"
+typedef double polyfit_type;
+
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++)
+ const int wdepth = DataType<polyfit_type>::depth;
+ int npoints = src_x.checkVector(1);
+ int nypoints = src_y.checkVector(1);
+
+ CV_Assert(npoints == nypoints && npoints >= order+1);
+
+ Mat srcX = Mat_<polyfit_type>(src_x), srcY = Mat_<polyfit_type>(src_y);
+
+ Mat X = Mat::zeros(order + 1, npoints, wdepth);
+ polyfit_type* pSrcX = (polyfit_type*)srcX.data;
+ polyfit_type* pXData = (polyfit_type*)X.data;
+ int stepX = (int)(X.step/X.elemSize1());
+ for (int y = 0; y < order + 1; ++y)
{
- copy = src_x.clone();
- pow(copy,i,copy);
- Mat M1 = X.col(i);
- copy.col(0).copyTo(M1);
+ for (int x = 0; x < npoints; ++x)
+ {
+ if (y == 0)
+ pXData[x] = 1;
+ else if (y == 1)
+ pXData[x + stepX] = pSrcX[x];
+ else pXData[x + y*stepX] = pSrcX[x]* pXData[x + (y-1)*stepX];
+ }
}
- 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);
+
+ Mat A, b, w;
+ mulTransposed(X, A, false);
+ b = X*srcY;
+ solve(A, b, w, DECOMP_SVD);
+ w.convertTo(dst, std::max(std::max(src_x.depth(), src_y.depth()), CV_32F));
}