//
// The true inverse cumulative sum will be in the range [lower, upper).
func (d *mud) approxInvCumulativeSum() (float64, float64, bool) {
	if d.trackBucket == len(d.hist) {
		return math.NaN(), math.NaN(), false
	}
	return float64(d.trackBucket) / mudDegree, float64(d.trackBucket+1) / mudDegree, true
}

// invCumulativeSum returns x such that the integral of d from -∞ to x

	qt := qs.QStats
	m.Set(replicationAverageQueuedBytes, float64(qt.Avg.Bytes))
	m.Set(replicationAverageQueuedCount, float64(qt.Avg.Count))
	m.Set(replicationMaxQueuedBytes, float64(qt.Max.Bytes))
	m.Set(replicationMaxQueuedCount, float64(qt.Max.Count))
	m.Set(replicationLastMinuteQueuedBytes, float64(qt.Curr.Bytes))
	m.Set(replicationLastMinuteQueuedCount, float64(qt.Curr.Count))

	qa := qs.ActiveWorkers

	m.Set(driveUsedBytes, float64(drive.UsedSpace), labels...)
	m.Set(driveFreeBytes, float64(drive.AvailableSpace), labels...)
	m.Set(driveTotalBytes, float64(drive.TotalSpace), labels...)
	m.Set(driveUsedInodes, float64(drive.UsedInodes), labels...)
	m.Set(driveFreeInodes, float64(drive.FreeInodes), labels...)
	m.Set(driveTotalInodes, float64(drive.UsedInodes+drive.FreeInodes), labels...)

			}
			addGauge(volumeStatsCapacityBytesDesc, pvcRef, float64(*volumeStat.CapacityBytes))
			addGauge(volumeStatsAvailableBytesDesc, pvcRef, float64(*volumeStat.AvailableBytes))
			addGauge(volumeStatsUsedBytesDesc, pvcRef, float64(*volumeStat.UsedBytes))
			addGauge(volumeStatsInodesDesc, pvcRef, float64(*volumeStat.Inodes))
			addGauge(volumeStatsInodesFreeDesc, pvcRef, float64(*volumeStat.InodesFree))

	m.readsPerSec = float64(ioStats.ReadIOs) / durationSecs
	m.readsKBPerSec = float64(ioStats.ReadSectors) * float64(sectorSize) / kib / durationSecs
	if ioStats.ReadIOs > 0 {
		m.readsAwait = float64(ioStats.ReadTicks) / float64(ioStats.ReadIOs)
	}

	m.writesPerSec = float64(ioStats.WriteIOs) / durationSecs
	m.writesKBPerSec = float64(ioStats.WriteSectors) * float64(sectorSize) / kib / durationSecs

var rn, kn, wn, fn = GetNormalDistributionParameters()
var re, ke, we, fe = GetExponentialDistributionParameters()

type statsResults struct {
	mean        float64
	stddev      float64
	closeEnough float64
	maxError    float64
}

func nearEqual(a, b, closeEnough, maxError float64) bool {
	absDiff := math.Abs(a - b)
	if absDiff < closeEnough { // Necessary when one value is zero and one value is close to zero.
		return true
	}

		return nil
	}

	nstats := globalEventNotifier.targetList.Stats()
	m.Set(notificationCurrentSendInProgress, float64(nstats.CurrentSendCalls))
	m.Set(notificationEventsErrorsTotal, float64(nstats.EventsErrorsTotal))
	m.Set(notificationEventsSentTotal, float64(nstats.TotalEvents))
	m.Set(notificationEventsSkippedTotal, float64(nstats.EventsSkipped))

	return nil

		"Delay in seconds between the first config enters debouncing and the merged push request is pushed into the push queue.",
		[]float64{.01, .1, 1, 3, 5, 10, 20, 30},
	)

	pushContextInitTime = monitoring.NewDistribution(
		"pilot_pushcontext_init_seconds",
		"Total time in seconds Pilot takes to init pushContext.",
		[]float64{.01, .1, 0.5, 1, 3, 5},
	)

	pushTime = monitoring.NewDistribution(
		"pilot_xds_push_time",

	m.Set(scannerBucketScansFinished, float64(globalScannerMetrics.lifetime(scannerMetricScanBucketDrive)))
	m.Set(scannerBucketScansStarted, float64(globalScannerMetrics.lifetime(scannerMetricScanBucketDrive)+uint64(globalScannerMetrics.activeDrives())))
	m.Set(scannerDirectoriesScanned, float64(globalScannerMetrics.lifetime(scannerMetricScanFolder)))
	m.Set(scannerObjectsScanned, float64(globalScannerMetrics.lifetime(scannerMetricScanObject)))

	// Insert random uniforms and check histogram mass and
	// cumulative sum approximations.
	rnd := rand.New(rand.NewSource(42))
	mass := 0.0
	var mud mud
	for i := 0; i < 100; i++ {
		area, l, r := rnd.Float64(), rnd.Float64(), rnd.Float64()
		if rnd.Intn(10) == 0 {
			r = l
		}
		t.Log(l, r, area)
		mud.add(l, r, area)
		mass += area

		// Check total histogram weight.
		hmass := 0.0
		for _, val := range mud.hist {