code: private boolean computeEigenValues() {
         // make a copy of the internal tridiagonal matrix data for later use
         diagSaved = helper.copyDiag(diagSaved);
         offSaved = helper.copyOff(offSaved);
  
         vector.setQ(null);
         vector.setFastEigenvalues(true);
  
         // extract the eigenvalues
         if( !vector.process(-1,null,null) )
             return false;
  
         // save a copy of them since this data structure will be recycled next
         values = helper.copyEigenvalues(values);
         return true;
     }
docs: Computes eigenvalues only
  
  @return