Due to the 9/11 markets interruption, daily bars were missing several days in a row. 9/10 and then 9/17 appear consecutive in many series.
Switching a chart from daily to weekly bars causes indicators to fail at that part of the chart. A version of the WilliamsAD, for example, goes to zero. Others drop radically. I suppose some rise to infinity. I have not noticed this when switching to monthly bars. Of course 9/11 is not the only possible multi-day market interruption that could affect weekly versions of indicators. Aside from a change in how AB handles the conversion from daily to weekly bars, does anyone have ideas for elegant AFL that can keep indicators sane? A general solution that is simple, does *not* check for specific historical dates, and works only when the chart interval is set to weekly? I apologize if this is already documented elsewhere. I did not see a solution with quick searches of "9/11" or "September 2001" in Yahoo or in the code library. I found this with potentially useful functions, but I wonder if its ideas can be made to work when the interval is weekly: <http://www.amibroker.com/library/formula.php?id=223> Best regards, Whitney
