Numerical protection.
authorbelikov <belikov@f7af4fe6-9843-0410-8265-dc069ae4e863>
Thu, 6 Jul 2006 07:19:22 +0000 (07:19 +0000)
committerbelikov <belikov@f7af4fe6-9843-0410-8265-dc069ae4e863>
Thu, 6 Jul 2006 07:19:22 +0000 (07:19 +0000)
STEER/AliESDv0.cxx

index 64a7225..ff65fec 100644 (file)
@@ -108,8 +108,9 @@ AliESDv0::AliESDv0(const AliExternalTrackParam &t1, Int_t i1,
   Double_t sx2=sn*sn*t2.GetSigmaY2(), sy2=cs*cs*t2.GetSigmaY2(); 
     
   Double_t sz1=t1.GetSigmaZ2(), sz2=t2.GetSigmaZ2();
-  Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
-  Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
+  const Double_t ss=0.0005*0.0005;//a kind of a residual misalignment precision
+  Double_t wx1=sx2/(sx1+sx2+ss), wx2=1.- wx1;
+  Double_t wy1=sy2/(sy1+sy2+ss), wy2=1.- wy1;
   Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
   fPos[0]=wx1*x1 + wx2*x2; fPos[1]=wy1*y1 + wy2*y2; fPos[2]=wz1*z1 + wz2*z2;