Align time series data if possible

pkg/timeseries/align.go

@@ -0,0 +1,52 @@
+package timeseries
+
+import (
+	"math"
+	"sort"
+	"time"
+)
+
+// Aligns point's time stamps according to provided interval.
+func (ts TimeSeries) Align(interval time.Duration) TimeSeries {
+	if interval <= 0 || ts.Len() < 2 {
+		return ts
+	}
+
+	alignedTs := NewTimeSeries()
+	var frameTs = ts[0].GetTimeFrame(interval)
+	var pointFrameTs time.Time
+	var point TimePoint
+
+	for i := 0; i < ts.Len(); i++ {
+		point = ts[i]
+		pointFrameTs = point.GetTimeFrame(interval)
+
+		if pointFrameTs.After(frameTs) {
+			for frameTs.Before(pointFrameTs) {
+				alignedTs = append(alignedTs, TimePoint{Time: frameTs, Value: nil})
+				frameTs = frameTs.Add(interval)
+			}
+		}
+
+		alignedTs = append(alignedTs, TimePoint{Time: pointFrameTs, Value: point.Value})
+		frameTs = frameTs.Add(interval)
+	}
+
+	return alignedTs
+}
+
+// Detects interval between data points in milliseconds based on median delta between points.
+func (ts TimeSeries) DetectInterval() time.Duration {
+	if ts.Len() < 2 {
+		return 0
+	}
+
+	deltas := make([]int, 0)
+	for i := 1; i < ts.Len(); i++ {
+		delta := ts[i].Time.Sub(ts[i-1].Time)
+		deltas = append(deltas, int(delta.Milliseconds()))
+	}
+	sort.Ints(deltas)
+	midIndex := int(math.Floor(float64(len(deltas)) * 0.5))
+	return time.Duration(deltas[midIndex]) * time.Millisecond
+}