Hi Gang, I was wondered how I would write an explorer to look for say a crossing of the 50 dma over the 200 dma "within the last x days". I've got the cross part Cross(Mov(C,50,E), Mov(C,200,E)), I just don't know how to say "within the last x days". Thanks in advance for your help!

Jose, That worked, thank you very much!

CK You're probably running the exploaration set to "Load Minimum Records". For a 200 day EMA you need to set that to between 500 and 1000 records to get an accurate 200 day EMA. Longer is better. As a rule of thumb you should force an exploration with an EMA to load about 5 times as much data as the longest ema periods value in your explorations formula. The same rule of thumb applies to explorations using any function with Wilders() or an EMA internally. This includes RSI(), ADX(), etc. etc. etc.. Also, the Alert function doen't extend an alert with the Explorer when it's set to minimum records. Technically it would work with 221 bars set, as per Jose's Alert() example, but the 200 day EMA would probably be so away from the chart value of the same EMA for the alert to be totally useless anyway. Roy MetaStock Tips & Tools

CK The MetaStock method of calculating an EMA may well be different from other charting packages - I simply don't know. The MS method retains a fragment of ALL past historical data, not just data within the "periods" parameter. For example, a 7 period EMA adds 25% of new data (current bars close?) on each bar, and retains 75% of old data. The proportion of existing data retained or preplaced is determined by the ratio of 2/(n+1), where "n" is the periods parameter. The ratio for Wilders Smoothing is 1/n. {7 Period Exponential Moving Average} R:=2/(7+1); If(Cum(1)=1,C,PREV*(1-R)+C*R); Without knowing how other packages calulate an EMA it's difficult to assign "right" and "wrong". I'm sticking with "different". The MetaStock user manual spells out how its EMA is constructed. You'd have to check whether the other packages have the same information. That might at least explain the difference, and a remedy might follow on from there. Roy MetaStock Tips & Tools

I am curious about a slight change to the condition mentioned about representing a single cross. How could it be written if one wanted to see the cross of the 9 of the 21, then the 21 of the 50 day moving average all within a 10 bar period of time? Thanks

Rhone Try this BarsSince(Cross(Mov(C,9,E),Mov(C,21,E)))<11 AND Cross(Mov(C,21,E),Mov(C,50,E)); Roy MetaStock Tips & Tools

I use bigcharts.com, yahoo.com and stockcharts.com The problem I am having is with the display of the MA's because the exploration works, ie: it shows me stocks where the 50dma has crossed the 200dma. However on visual inspection the 2 MA's are miles apart on MetaStock.

CK I wonder if the reason the two MAs are "miles apart" is because one or both of them are unscaled instead of being locked to the same scale as the price chart. Right click on each MA in turn and select the appropriate scale (Left or Right). Another way to check the relative values of price and MAs is to open the data window (crosshairs on taskbar) and read off the values while moving the cursor over the relevant bars. Exploration columns are simply indicators without a visual output (last value report only), so there's no valid reason why a chart and exploration would tell you different things except for when the amount of data loaded is different from one to the other. Whether you know it or not everything is under your control. When something doesn't look right on a chart there's always a good reason, never a problem with MetaStock in my experience. Roy MetaStock Tips & Tools