The Elastic Volume Weighted Moving Average (eVWMA) differs from usual average in that :
- It does not refer to any underlying averaging time period (for example, 20 days, 50 days, 200 days). Instead, eVWMA uses share volume to define the period of the averaging.
- It incorporates information about volume (and possibly time) in a natural and logical way
- It can be derived from, and seen as an approximation to, a statistical measure and thus has a solid mathematical justification.
to use I:EVWMA one must have a database containing the number of shares floating for each security being analyzed. this shares_float database is only searched for in an xml file at /bourse/metainfo/"$code".xml
currently the beancounter database doesn't store this security attribute, nor does beancounter fetch this value in the course of a normal daily update.
yahoo does provide the attribute via 'f6', but how one might create the required xml file based database is not described.
eVWMA(0) = Today's Close
eVWMA(i) = ( (Number of shares floating - Today's Volume) \
* eVWMA(i-1) + Today's Volume * Today's Close ) \
/ Number of shares floating
GT::Indicators::EVWMA->new()
http://www.christian-fries.de/evwma/ http://www.linnsoft.com/tour/techind/evwma.htm