highchart - average value of serie for shown period - average

Question

Using Highstock, I've a serie timestamp / value
with different rangeselectors (hour, day, week, month,...) or zoomX
I want to display the average value for the displayed time period.
Now, I can compute the average of the overall series data:
for (i = 0; i < chart.series[0].yData.length; i++) {
total += chart.series[0].yData[i];
}
seriesAvg = (total / chart.series[0].yData.length).toFixed(4); // fix decimal to 4 places
$('#report1').html('<b>Average:</b>: '+ seriesAvg);
How to compute the average only on the displayed datapoints ? And to refresh automatically after zoom ?
Thank you

Answer 1

Use series.processedYData or series.points.

Answer 2

I implemented the same but I notice that processedYdata is loading also one data more than the one showed at the screen.
for that reason i added one additional command to remove the first processedYData:
processedYData.splice(0, 1);
below is the final result of the function
function showStat(objHighStockchart) {
for (j = 0; j < (json_data.length); j++) {
var seriesAvg = 0,
processedYData = objHighStockchart.series[j].processedYData;
processedYData.splice(0, 1);
var seriesMin = Math.min.apply(null, processedYData);
var seriesMax = Math.max.apply(null, processedYData);
var i = 0
var total = 0;
console.log(processedYData);
for (i = 1; i < processedYData.length; i++) {
total += processedYData[i];
}
seriesAvg = (total / processedYData.length).toFixed(2); // fix decimal to 4 places
$('#container_stat' + j).html(
'<br>Statistics for ' + objHighStockchart.series[j].name + '<br>' +
'Total: ' + total + ' logs<br>' +
'Min: ' + seriesMin + ' logs<br>' +
'Avg: ' + seriesAvg + ' logs<br>' +
'Max: ' + seriesMax + ' logs<br>'
+ '---' + processedYData
);
}
};