double ab[3]={coo[3]-coo[0],coo[4]-coo[1],coo[5]-coo[2]};
double ac[3]={coo[6]-coo[0],coo[7]-coo[1],coo[8]-coo[2]};
double ad[3]={coo[9]-coo[0],coo[10]-coo[1],coo[11]-coo[2]};
- double detTet=(ab[0]*(ac[1]*ad[2]-ac[2]*ad[1]))+(ab[1]*(ac[2]*ad[0]-ac[0]*ad[2]))+(ab[2]*(ac[0]*ad[1]-ac[1]*ad[2]));
+ double detTet=(ab[0]*(ac[1]*ad[2]-ac[2]*ad[1]))+(ab[1]*(ac[2]*ad[0]-ac[0]*ad[2]))+(ab[2]*(ac[0]*ad[1]-ac[1]*ad[0]));
//if(detTet<1.e-15)
// return std::numeric_limits<double>::max();
double bc[3]={coo[6]-coo[3],coo[7]-coo[4],coo[8]-coo[5]};