最小二乘法擬合圓公式推導及vc實現[r]
阿新 • • 發佈:2018-12-11
{ if (m_nNum<3) { return; } int i=0; double X1=0; double Y1=0; double X2=0; double Y2=0; double X3=0; double Y3=0; double X1Y1=0; double X1Y2=0; double X2Y1=0; for (i=0;i<m_nNum;i++) { X1 = X1 + m_points[i].x; Y1 = Y1 + m_points[i].y; X2 = X2 + m_points[i].x*m_points[i].x; Y2 = Y2 + m_points[i].y*m_points[i].y; X3 = X3 + m_points[i].x*m_points[i].x*m_points[i].x; Y3 = Y3 + m_points[i].y*m_points[i].y*m_points[i].y; X1Y1 = X1Y1 + m_points[i].x*m_points[i].y; X1Y2 = X1Y2 + m_points[i].x*m_points[i].y *m_points[i].y; X2Y1 = X2Y1 + m_points[i].x*m_points[i].x*m_points[i].y; } double C,D,E,G,H,N; double a,b,c; N = m_nNum; C = N*X2 - X1*X1; D = N*X1Y1 - X1*Y1; E = N*X3 + N*X1Y2 - (X2+Y2)*X1; G = N*Y2 - Y1*Y1; H = N*X2Y1 + N*Y3 - (X2+Y2)*Y1; a = (H*D-E*G)/(C*G-D*D); b = (H*C-E*D)/(D*D-G*C); c =-(a*X1 + b*Y1 + X2 + Y2)/N; double A,B,R; A = a/(-2); B = b/(-2); R = sqrt(a*a+b*b-4*c)/2; m_fCenterX = A; m_fCenterY = B; m_fRadius = R; return;}