Is there a way to count back from the most current data entered? Something similar to the "Bars Since" function. For example if I move back three days from the latest most current data point, the function will count three time periods. I need to create an indicator that uses the number of counted time periods back from the most recent data and use that value to trigger a calculation.

Thanks,

dlipter

Roy,

Yes...your formula works like a charm!

I still have a vexing problem.

The formula: if(fml ("Bar Count- Reverse")>2, f1,f2) works fine where say f1 is a 5 period moving average and f2 is a 15 period moving average. It will plot f1 until 2 days before the last day, then for the final 2 days it plots f2.

Where the above "if" formula fails to work is where f1= Ref (Mov(MP( ),5,s),2) which is a 5 period MA displaced back 2 periods. In this case f2 doesn't plot for the final 2 days.

Ideas?

Thank's

dlipter

Hi dlipter

The cause of the problem is obvious to me but I'm not sure whether it's intentional on your part or not. Your "displaced back 2 periods" is actually giving you a displacement forward 2 periods (the Periods parameter for the Ref() function is positive rather than negative). Fix that and the problem will disappear. If you really want the MA to be moved forwards (into the future) then a solution eliminating N/A is possible but not quite as simple as just changing a parameter or two.

Roy

The formula Ref (Mov(MP( ),5,s),2) computes the average on lets say day 10 and plots that value on day 8, so the plotted average is moved back in time by 2 days. The value is always computed two days in advance. The plotted average will always trail the last data point by 2 days leaving the last two days blank. I want to substitute a proxy for the average on the two unplotted days using the If function to bring the plotted average forward to cover the last 2 data points using the third parameter in the If function.

The formula suggested Ref (Mov(MP( ),5,s),-2) using a -2 will plot an average displaced in the wrong direction resulting in an inaccurate representation of of the price data in the period. A simple average is only representative of the data in the period when it is plotted at the center of the period, hence my need to displace the average back 2 periods.

If you apply a trailing 5 day average and a centered 5 day average (displaced back in time by half the average length) over a price plot you will see that the centered average is superior in all aspects except that its plot lags the data by 1/2 the average length, in this case 2 days.

dlipter

Hi dlipter

Open the Data Window and pass the cursor over the last two data bars. What value is shown for the last two bars (and first two as well)? N/A means that no result is generated.

Roy

Here's one thought I had in mind. The last two bars plot the same value as the last valid bar. Whether that's relevant to what you're trying to do I don't know. What the Forum DLL Sum function does is convert an N/A result to a zero result - what you convert those zeros into is up to you.

Signal:=Ref(Mov(MP( ),5,S),2);
Defined:=IsDefined(Signal);
Signal:=ExtFml("Forum.Sum",Signal,1);
ValueWhen(1,Defined,Signal);

Roy

The Forum DLL is available as a free download from this site by going to http://forum.equis.com/files/default.aspx. It's labelled as "Forum Dll 200" but can be renamed anything you like. I prefer shorter names hence just "Forum" in my code - it's more economical with the limited space that MetaStock allows for each formula. If you have any version under a different name you can either change the name or change my code. The 188KB file is the latest and probably most useful/error-free version but as long as it's named differently it can coexist in MetaStock with earlier versions.

The User Manual was written by Wabbit for an earlier version and does not over all the functions offered by the "200" version. However you can identify the available functions and their syntax after installation by opening any indicator (or create a new one), and clicking in the Formula window then click on the functions button. Scroll down until you come to Forumand mark it. Yo'll see a lits offunctions in the Paste Function window and by marking any function you can read off the syntax from the Format window. DON'T click the OK button unless you want to paste the function into the indicator you have open.

Be aware that fuction names in Forum Dll 200 are not the same as those in Forum Dll 112 even when they do the same job.

Roy

Could the formula make the last two bars plot a function or custom indicator instead of the value of the last valid bar?

Lets say price midpoint as an example.

dlipter

So whatever function or custom indicator I drop in place of "Mid(C,5)" in the last line of the above formula will be plotted in the last two Bars?

I don't understand the syntax, you have two variables with the same name "Signal". "Signal" is mentioned in the 2nd, 3rd, and 4th line equations.

In the last line, "Signal" refers to the 1st line variable or the 3rd line variable. Since the formula plots line 1 it must refer to line 1.

Is this covered in the Formula Primer?