One condition of my explorer use 30-weeks moving average. However, this will result exclude stocks with less than 30-weeks data. So, I try to to alter the 30-weeks moving average with 12-weeks moving average for stocks with less than 30-weeks data, I use the following formulae: If(IsDefined(Mov(C,30,S))=1, mov(c,30,S),mov(c,12,S)) with this formulae, however, the stock with 12-30 weeks data is still being rejected - reason noted is "Period value out of Range in Mov() function". Can I get some help here, how can I get Explorer to do different set of function for stocks with less than 30-weeks data instead of rejecting them? Thank hips for any hints in advance! Tracy Huang

The IsDefined() and IsUnDefined() functions that are currently in MS are useless and do not meet the standard that yuo would think of this product. h was right... I did code up a .dll to handle this very situation where one data array could be substitued with another data array if the first array was not valid, but noone seemed interested in the code so I stopped its development. Like all things with MS there is a workaround using the Forum.dll and adaptive moving averages... Hope this helps. wabbit :D [thinking out loud] Maybe there is a use for my .dll after all?

The IsDefined() & IsUndefined() MetaStock functions have their use, but not in this case. Your easiest solution: [code:1:e8eb35e53f]SMAperiods:=30; altPeriods:=12; pds:=If(Cum(1)<SMAperiods,altPeriods,SMAperiods); ExtFml("ASI.SMA",C,pds) [/code:1:e8eb35e53f] I would do it this way: [code:1:e8eb35e53f]SMAperiods:=30; altPeriods:=12; pds:=If(Cum(1)<SMAperiods,Cum(1),SMAperiods); ExtFml("ASI.SMA",C,pds) [/code:1:e8eb35e53f] The ASI & Forum DLLs are available here from the download section. jose '-)