public void addGenerator(Distribution gen){
  if (trans != null) {
    throw new AbortException("Generators may no longer be added when transformations have been applied.");
  }
  axes.add(gen);
  dim++;
}

public void addGenerator ( Distribution gen ) { if ( trans != null ) { throw new AbortException ( "Generators may no longer be added when transformations have been applied." ) ; } axes . add ( gen ) ; dim ++ ; }
add a new generator to the cluster . no transformations must have been added so far !
