code: public double percentOverlap( Location other )
  	{
  		if( length() > 0 && overlaps( other ))
  		{
  			return 100.0 * (((double) intersection( other ).length()) / (double) length());
  		}
  		else
  		{
  			return 0;
  		}
  	}
docs: Return percent overlap of two locations.
  
  @param other The location to compare.
  @return 100.0 * intersection(other).length() / this.length()
  @throws IllegalArgumentException Locations are on opposite strands.