I am trying to get the max and min values of an indicator over the full date range of a chart.
This looks like it should work, but it doesn't cover the whole chart, the "Bars" printout gives a number far lower than the bars in the chart, even if the backtest date range covers the whole chart.
I call it from init().
Why doesn't it work?

double ATRMin = 99999;
double ATRMax;

void ATR_HL()
{
for (int i=1;i<Bars-251;i++)
{
double ATR1 = iATR(NULL,0,250,i);
if (ATR1 < ATRMin) ATRMin = ATR1;
if (ATR1 > ATRMax) ATRMax = ATR1;

}
Print ("Bars ",Bars," ATR1 ",ATR1," ATRMin= ",ATRMin," ATRMAX ", ATRMax);
return(0);
}