수계망분석 방향

if( "FD" =0,'북',
   if( "FD" =1,'북동',
      if( "FD" =2,'동',
         if( "FD" =3,'남동',
            if( "FD" =4,'남',
               if( "FD" =5,'남서',
                  if( "FD" =6,'서',
                     if( "FD" =7,'북서','북북'
))))))))