Predefined scan fomula

Heisenberg_lee

Hello guys:
Recently I am studying the basic knowledge of screen formula. And I found that it is easy to write formula to search some bullish or bearish candlestick such as engulfing and hammer. But it is really hard to search some price patterns such as double top or double bottom. So I checked the predefined screen formula. Such as PnF Double Bottom Breakout. But the screen result seems to be not so much like the price pattern that I used read from books. I guess maybe I can modify the parameter of this formula. But is it possible that I can check the details of these predefined formula? Thank you

markd

It doesn't look like you can.

I selected a P&F pattern from a "Predefined" drop down on the Standard Scan Workbench, then hit Update Criteria, then hit Advanced Scan Workbench.

For some "Predefined" selections, you can see the code behind it on the Advanced Scan Workbench. But for this P&F selection you cannot. It just said "Double Bottom =1". I have a feeling it would be the same for the others.

I was not able to find documentation that describes how each pattern is defined either. Maybe @Gord would know.

gord

Yes candlestick scans can be quite simple as they usually only cover 2-4 days and they are fairly specific in their rules. When it comes to other chart patterns like double top or head & shoulders etc the rules are rather flexible and everyone has their own view on what they like. These patterns also evolve over various time periods, did the first top happen 2 weeks ago or maybe 6 months ago, the scan engine can't handle this type of fuzzy logic it needs mathematical formulas.

With respect to PnF charts here's a couple of links to articles in the ChartSchool section which document how PnF charts are created and also the theory behind how the scans can be created.

http://stockcharts.com/school/doku.php?id=chart_school:chart_analysis:pnf_charts

http://stockcharts.com/school/doku.php?id=chart_school:chart_analysis:pnf_charts:pnf_bearish_bd