[amibroker] How to use BarIndex from the start of the year?

[jim_wiehe]

I cant seem to get the BarIndex() count from a calendar date. 
Sometimes I get large numbers and sometimes no number.  I'm sure this
is a real easy one for the experienced Amibroker users.  Any help
would be greatly appreciated

Thanks in advance


start = ParamDate( "Start Date", "2008-01-01" );


TradingDaysfromStartofCalendarYear = ValueWhen( start,BarIndex(), 1);

ROCSinceStartOfYear=ROC(C,TradingDaysfromStartofCalendarYear );


Filter = C> 15 AND MA(V,10) >1000000;
Buy=Filter;
Sell=EMA(C,6)<EMA(C,7);
AddColumn( Close, "Close  ",1.2 );
AddColumn( ROC(C,1), "1 day %Chg  ",1.2 );
AddColumn( ROC(C,5), "5 day %Chg  ",1.2 );
AddColumn(ROCSinceStartOfYear,"ROC Year",1.2);