weird Empty4 behaviour, i agree ...!?!garyfritz wrote: Except... when I first set the color to NONE, MQL says it's -1, the currency color is == CLR_NONE, and the NONE currencies don't display. Then if I change one color, all the OTHER "NONE" colors spontaenously change to -16777216 !? Then the lines start displaying again, in black. If I use Pink, it works.:
-16777216 translates to 0xFFFFFFFFFF000000, which is NOT -1(decimal) encoded on a 64-bits value...
Perhaps because the "color" type is truncated or shifted somehow internally (possibly encoded on only 40 bits, then stored into 64-bits data storage...)
Let's keep it simple, who would display a Pink line anyway ?
correctI realized, though, that if I don't want to display an index, and I don't call SetIndexBuffer(), then Empty4 won't know it's a buffer and won't automagically shift it when Bar 0 closes. But that shouldn't matter because I'm not displaying it anyway, and I don't access it in any other calculations.
sq, when bar 0 closes and becomes bar 1, I need to shift all the arrays I use for MAs -- e.g. AUDindex[], AUDspeed[], AUDsmooth[]. What about the pair arrays? I load those up with e.g. "AUDUSD = iClose("AUDUSD",0,iBarShift("AUDUSD",0,iTime(NULL,0,i)));". So they should line up with the Bar data already. But when bar 0 closes, the Bar data shifts, and AUDUSD[] doesn't. The IndicatorCounted() value is probably only going to have me calling iClose() one one or two bars. So I should shift the AUDUSD[] pair array too, right?
absolutely;
you have to "manually" shift ANY non-buffer array that needs to keep up with the buffers.
I'll get this coded this weekend -- I think the changes from this point are pretty simple (famous last words??) -- but I can't test it until Sunday night so I won't release anything until at least then.
actually you CAN test it: load any EA in the visual backtester, Pause it, load the indi on the chart, then Run; it will display ALL the currencies, although an EA only has access to the selected symbol, because the indicator runs independently from the history data feed provided to the EA -- one more strange and misleading Empty4 behaviour...
PS: BTW I was thinking about how this really simple concept has exploded into hundreds of lines of code and lots of CPU-gobbling work to calculate the averages and maintain the history. Then I realized that about 98% of that is just dealing with the strange Empty4 indicator behavior. Calculating the raw index values is very simple.
Maybe, if you wanted to use the currency strength in an EA and NOT in an indicator, you might not have to drag along that extra 98%. Let me ping Steve and ask him exactly how EAs behave.
Well, an EA does not even have the "buffers" available.
So an EA would have to calc everything manually by itself, thru the same arrays as in the indi.
However, you can save several arrays by implementing your own EMA "incremental" function, because EMA only needs to know the "previous bar" EMA and the current data value to calc the current EMA.
You only need "push" the current EMA into the "previous_EMA" value at each new bar-opening, without the need to handle of whole lot of arrays.
init() would make the first EMA calculations.
Something like this:
Code: Select all
double ema_now(double previous_ema, double current_data, int ema_period)
{
double alpha = 2*(ema_period+1);
return (alpha * current_data + (1-alpha) * previous_ema);
}
It would be a bunch of lines of code...
Sq