read(paramtop, "j_decay", param.j_decay);
void read(XMLReader& xml, const string& path, Param_t& param){  XMLReader paramtop(xml, path);  int version;  read(paramtop, "version", version);  switch (version)   {  case 3:    read(paramtop, "link_smear_num", param.link_smear_num);    if( param.link_smear_num < 0 )    {      QDP_error_exit( "hypsmear.cc: invalid number of hyp smearing iterations, link_smear_num = %d", param.link_smear_num );    }    break;  case 2:    param.link_smear_num = 1;    break;  default :    QDPIO::cerr << "Input version " << version << " unsupported." << endl;    QDP_abort(1);  }  read(paramtop, "alpha1", param.alpha1);  read(paramtop, "alpha2", param.alpha2);  read(paramtop, "alpha3", param.alpha3);  read(paramtop, "nrow", param.nrow);  read(paramtop, "j_decay", param.j_decay);}