private double GetLast(string dsName, string rpnExpression)
{
RpnCalculator rpnCalculator = null;
if(rpnExpression != null)
{
rpnCalculator = new RpnCalculator(rpnExpression);
}
double [] vals = GetValues(dsName);
double val = vals[vals.Length - 1];
if(rpnCalculator != null)
{
rpnCalculator.Value = val;
val = rpnCalculator.Calculate();
}
return val;
}
private double GetMin(string dsName, string rpnExpression)
{
RpnCalculator rpnCalculator = null;
if(rpnExpression != null)
{
rpnCalculator = new RpnCalculator(rpnExpression);
}
double [] vals = GetValues(dsName);
double min = Double.NaN;
for(int i = 0; i < vals.Length - 1; i++)
{
double val = vals[i + 1];
if(rpnCalculator != null)
{
rpnCalculator.Value = val;
val = rpnCalculator.Calculate();
}
min = Util.Min(min, val);
}
return min;
}
private double GetAverage(string dsName, string rpnExpression)
{
RpnCalculator rpnCalculator = null;
if(rpnExpression != null)
{
rpnCalculator = new RpnCalculator(rpnExpression);
}
double [] vals = GetValues(dsName);
double totalVal = 0;
long totalSecs = 0;
for(int i = 0; i < vals.Length - 1; i++)
{
long t1 = Math.Max(request.FetchStart, timestamps[i]);
long t2 = Math.Min(request.FetchEnd, timestamps[i + 1]);
double val = vals[i + 1];
if(rpnCalculator != null)
{
rpnCalculator.Value = val;
val = rpnCalculator.Calculate();
}
if(!Double.IsNaN(val))
{
totalSecs += (t2 - t1);
totalVal += (t2 - t1) * val;
}
}
return totalSecs > 0? totalVal / totalSecs: Double.NaN;
}