public int minusDMLookback( int optInTimePeriod )
   {
      if( (int)optInTimePeriod == ( Integer.MIN_VALUE ) )
         optInTimePeriod = 14;
      else if( ((int)optInTimePeriod < 1) || ((int)optInTimePeriod > 100000) )
         return -1;
      if( optInTimePeriod > 1 )
         return optInTimePeriod + (this.unstablePeriod[FuncUnstId.MinusDM.ordinal()]) - 1;
      else
         return 1;
   }