Ignore nulls unless 'null as zero' for series.stats.avg

public/app/core/time_series.ts

@@ -98,6 +98,7 @@ class TimeSeries {
     var nullAsZero = fillStyle === 'null as zero';
     var currentTime;
     var currentValue;
+    var nonNulls = 0;
 
     for (var i = 0; i < this.datapoints.length; i++) {
       currentValue = this.datapoints[i][0];
@@ -114,6 +115,7 @@ class TimeSeries {
         if (_.isNumber(currentValue)) {
           this.stats.total += currentValue;
           this.allIsNull = false;
+          nonNulls++;
         }
 
         if (currentValue > this.stats.max) {
@@ -136,7 +138,7 @@ class TimeSeries {
     if (this.stats.min === Number.MAX_VALUE) { this.stats.min = null; }
 
     if (result.length) {
-      this.stats.avg = (this.stats.total / result.length);
+      this.stats.avg = (this.stats.total / nonNulls);
       this.stats.current = result[result.length-1][1];
       if (this.stats.current === null && result.length > 1) {
         this.stats.current = result[result.length-2][1];

public/test/core/time_series_specs.js

@@ -43,6 +43,17 @@ define([
         expect(series.stats.max).to.be(-4);
       });
 
+      it('average value should ignore nulls', function() {
+        series = new TimeSeries(testData);
+        series.getFlotPairs('null', yAxisFormats);
+        expect(series.stats.avg).to.be(6.333333333333333);
+      });
+
+      it('with null as zero style, average value should treat nulls as 0', function() {
+        series = new TimeSeries(testData);
+        series.getFlotPairs('null as zero', yAxisFormats);
+        expect(series.stats.avg).to.be(4.75);
+      });
     });
 
     describe('series overrides', function() {