code: public void setExpansion(double expansion) 
      {
          if(expansion <= 1 || Double.isNaN(expansion) || Double.isInfinite(expansion) )
              throw new ArithmeticException("Expansion constant must be > 1, not " + expansion);
          else if(expansion <= reflection)
              throw new ArithmeticException("Expansion constant must be less than the reflection constant");
          this.expansion = expansion;
      }
docs: Sets the expansion constant, which must be greater than 1 and the reflection constant
  @param expansion