+
+
+//________________________________
+void AliTrackPoint::SetAlignCovMatrix(const TMatrixDSym alignparmtrx){
+ // Add the uncertainty on the cluster position due to alignment
+ // (using the 6x6 AliAlignObj Cov. Matrix alignparmtrx) to the already
+ // present Cov. Matrix
+
+ TMatrixDSym cov(3);
+ TMatrixD coval(3,3);
+ TMatrixD jacob(3,6);
+ Float_t newcov[6];
+
+ cov(0,0)=fCov[0];
+ cov(1,0)=cov(0,1)=fCov[1];
+ cov(2,0)=cov(0,2)=fCov[2];
+ cov(1,1)=fCov[3];
+ cov(2,1)=cov(1,2)=fCov[4];
+ cov(2,2)=fCov[5];
+
+ jacob(0,0) = 1; jacob(1,0) = 0; jacob(2,0) = 0;
+ jacob(0,1) = 0; jacob(1,1) = 1; jacob(2,1) = 0;
+ jacob(0,2) = 0; jacob(1,2) = 0; jacob(2,2) = 1;
+ jacob(0,3) = 0; jacob(1,3) =-fZ; jacob(2,3) = fY;
+ jacob(0,4) = fZ; jacob(1,4) = 0; jacob(2,4) =-fX;
+ jacob(0,5) = fY; jacob(1,5) = fX; jacob(2,5) = 0;
+
+ TMatrixD jacobT=jacob.T();jacob.T();
+
+ coval=jacob*alignparmtrx*jacobT+cov;
+
+
+ newcov[0]=coval(0,0);
+ newcov[1]=coval(1,0);
+ newcov[2]=coval(2,0);
+ newcov[3]=coval(1,1);
+ newcov[4]=coval(2,1);
+ newcov[5]=coval(2,2);
+
+ SetXYZ(fX,fY,fZ,newcov);
+
+}