feat: change statistics render of metric plot to min/max/median

- #263

api/schema.graphqls

@@ -151,6 +151,7 @@ type MetricStatistics {
 
 type StatsSeries {
   mean:   [NullableFloat!]!
+  median: [NullableFloat!]!
   min:    [NullableFloat!]!
   max:    [NullableFloat!]!
 }

internal/graph/generated/generated.go

@@ -253,6 +253,7 @@ type ComplexityRoot struct {
 	StatsSeries struct {
 		Max    func(childComplexity int) int
 		Mean   func(childComplexity int) int
+		Median func(childComplexity int) int
 		Min    func(childComplexity int) int
 	}
 
@@ -1344,6 +1345,13 @@ func (e *executableSchema) Complexity(typeName, field string, childComplexity in
 
 		return e.complexity.StatsSeries.Mean(childComplexity), true
 
+	case "StatsSeries.median":
+		if e.complexity.StatsSeries.Median == nil {
+			break
+		}
+
+		return e.complexity.StatsSeries.Median(childComplexity), true
+
 	case "StatsSeries.min":
 		if e.complexity.StatsSeries.Min == nil {
 			break
@@ -1868,6 +1876,7 @@ type MetricStatistics {
 
 type StatsSeries {
   mean:   [NullableFloat!]!
+  median: [NullableFloat!]!
   min:    [NullableFloat!]!
   max:    [NullableFloat!]!
 }
@@ -4854,6 +4863,8 @@ func (ec *executionContext) fieldContext_JobMetric_statisticsSeries(ctx context.
 			switch field.Name {
 			case "mean":
 				return ec.fieldContext_StatsSeries_mean(ctx, field)
+			case "median":
+				return ec.fieldContext_StatsSeries_median(ctx, field)
 			case "min":
 				return ec.fieldContext_StatsSeries_min(ctx, field)
 			case "max":
@@ -8814,6 +8825,50 @@ func (ec *executionContext) fieldContext_StatsSeries_mean(ctx context.Context, f
 	return fc, nil
 }
 
+func (ec *executionContext) _StatsSeries_median(ctx context.Context, field graphql.CollectedField, obj *schema.StatsSeries) (ret graphql.Marshaler) {
+	fc, err := ec.fieldContext_StatsSeries_median(ctx, field)
+	if err != nil {
+		return graphql.Null
+	}
+	ctx = graphql.WithFieldContext(ctx, fc)
+	defer func() {
+		if r := recover(); r != nil {
+			ec.Error(ctx, ec.Recover(ctx, r))
+			ret = graphql.Null
+		}
+	}()
+	resTmp, err := ec.ResolverMiddleware(ctx, func(rctx context.Context) (interface{}, error) {
+		ctx = rctx // use context from middleware stack in children
+		return obj.Median, nil
+	})
+	if err != nil {
+		ec.Error(ctx, err)
+		return graphql.Null
+	}
+	if resTmp == nil {
+		if !graphql.HasFieldError(ctx, fc) {
+			ec.Errorf(ctx, "must not be null")
+		}
+		return graphql.Null
+	}
+	res := resTmp.([]schema.Float)
+	fc.Result = res
+	return ec.marshalNNullableFloat2ᚕgithubᚗcomᚋClusterCockpitᚋccᚑbackendᚋpkgᚋschemaᚐFloatᚄ(ctx, field.Selections, res)
+}
+
+func (ec *executionContext) fieldContext_StatsSeries_median(ctx context.Context, field graphql.CollectedField) (fc *graphql.FieldContext, err error) {
+	fc = &graphql.FieldContext{
+		Object:     "StatsSeries",
+		Field:      field,
+		IsMethod:   false,
+		IsResolver: false,
+		Child: func(ctx context.Context, field graphql.CollectedField) (*graphql.FieldContext, error) {
+			return nil, errors.New("field of type NullableFloat does not have child fields")
+		},
+	}
+	return fc, nil
+}
+
 func (ec *executionContext) _StatsSeries_min(ctx context.Context, field graphql.CollectedField, obj *schema.StatsSeries) (ret graphql.Marshaler) {
 	fc, err := ec.fieldContext_StatsSeries_min(ctx, field)
 	if err != nil {
@@ -14427,6 +14482,11 @@ func (ec *executionContext) _StatsSeries(ctx context.Context, sel ast.SelectionS
 			if out.Values[i] == graphql.Null {
 				out.Invalids++
 			}
+		case "median":
+			out.Values[i] = ec._StatsSeries_median(ctx, field, obj)
+			if out.Values[i] == graphql.Null {
+				out.Invalids++
+			}
 		case "min":
 			out.Values[i] = ec._StatsSeries_min(ctx, field, obj)
 			if out.Values[i] == graphql.Null {

internal/metricdata/metricdata.go

@@ -263,7 +263,7 @@ func cacheKey(
 
 // For /monitoring/job/<job> and some other places, flops_any and mem_bw need
 // to be available at the scope 'node'. If a job has a lot of nodes,
-// statisticsSeries should be available so that a min/mean/max Graph can be
+// statisticsSeries should be available so that a min/median/max Graph can be
 // used instead of a lot of single lines.
 func prepareJobData(
 	job *schema.Job,

internal/util/statistics.go

@@ -4,7 +4,13 @@
 // license that can be found in the LICENSE file.
 package util
 
-import "golang.org/x/exp/constraints"
+import (
+	"fmt"
+	"math"
+	"sort"
+
+	"golang.org/x/exp/constraints"
+)
 
 func Min[T constraints.Ordered](a, b T) T {
 	if a < b {
@@ -19,3 +25,36 @@ func Max[T constraints.Ordered](a, b T) T {
 	}
 	return b
 }
+
+func sortedCopy(input []float64) []float64 {
+	sorted := make([]float64, len(input))
+	copy(sorted, input)
+	sort.Float64s(sorted)
+	return sorted
+}
+
+func Mean(input []float64) (float64, error) {
+	if len(input) == 0 {
+		return math.NaN(), fmt.Errorf("input array is empty: %#v", input)
+	}
+	sum := 0.0
+	for _, n := range input {
+		sum += n
+	}
+	return sum / float64(len(input)), nil
+}
+
+func Median(input []float64) (median float64, err error) {
+	c := sortedCopy(input)
+	// Even numbers: add the two middle numbers, divide by two (use mean function)
+	// Odd numbers: Use the middle number
+	l := len(c)
+	if l == 0 {
+		return math.NaN(), fmt.Errorf("input array is empty: %#v", input)
+	} else if l%2 == 0 {
+		median, _ = Mean(c[l/2-1 : l/2+1])
+	} else {
+		median = c[l/2]
+	}
+	return median, nil
+}

pkg/schema/metrics.go

@@ -10,6 +10,8 @@ import (
 	"math"
 	"sort"
 	"unsafe"
+
+	"github.com/ClusterCockpit/cc-backend/internal/util"
 )
 
 type JobData map[string]map[MetricScope]*JobMetric
@@ -36,6 +38,7 @@ type MetricStatistics struct {
 
 type StatsSeries struct {
 	Mean        []Float         `json:"mean"`
+	Median      []Float         `json:"median"`
 	Min         []Float         `json:"min"`
 	Max         []Float         `json:"max"`
 	Percentiles map[int][]Float `json:"percentiles,omitempty"`
@@ -120,7 +123,7 @@ func (jd *JobData) Size() int {
 		for _, metric := range scopes {
 			if metric.StatisticsSeries != nil {
 				n += len(metric.StatisticsSeries.Max)
-				n += len(metric.StatisticsSeries.Mean)
+				n += len(metric.StatisticsSeries.Median)
 				n += len(metric.StatisticsSeries.Min)
 			}
 
@@ -149,53 +152,74 @@ func (jm *JobMetric) AddStatisticsSeries() {
 		}
 	}
 
-	min, mean, max := make([]Float, n), make([]Float, n), make([]Float, n)
+	// mean := make([]Float, n)
+	min, median, max := make([]Float, n), make([]Float, n), make([]Float, n)
 	i := 0
 	for ; i < m; i++ {
-		smin, ssum, smax := math.MaxFloat32, 0.0, -math.MaxFloat32
+		seriesCount := len(jm.Series)
+		// ssum := 0.0
+		smin, smed, smax := math.MaxFloat32, make([]float64, seriesCount), -math.MaxFloat32
 		notnan := 0
-		for j := 0; j < len(jm.Series); j++ {
+		for j := 0; j < seriesCount; j++ {
 			x := float64(jm.Series[j].Data[i])
 			if math.IsNaN(x) {
 				continue
 			}
 
 			notnan += 1
-			ssum += x
+			// ssum += x
+			smed[j] = x
 			smin = math.Min(smin, x)
 			smax = math.Max(smax, x)
 		}
 
 		if notnan < 3 {
 			min[i] = NaN
-			mean[i] = NaN
+			// mean[i] = NaN
+			median[i] = NaN
 			max[i] = NaN
 		} else {
 			min[i] = Float(smin)
-			mean[i] = Float(ssum / float64(notnan))
+			// mean[i] = Float(ssum / float64(notnan))
 			max[i] = Float(smax)
+
+			medianRaw, err := util.Median(smed)
+			if err != nil {
+				median[i] = NaN
+			} else {
+				median[i] = Float(medianRaw)
+			}
 		}
 	}
 
 	for ; i < n; i++ {
 		min[i] = NaN
-		mean[i] = NaN
+		// mean[i] = NaN
+		median[i] = NaN
 		max[i] = NaN
 	}
 
 	if smooth {
-		for i := 2; i < len(mean)-2; i++ {
+		for i := 2; i < len(median)-2; i++ {
 			if min[i].IsNaN() {
 				continue
 			}
 
 			min[i] = (min[i-2] + min[i-1] + min[i] + min[i+1] + min[i+2]) / 5
 			max[i] = (max[i-2] + max[i-1] + max[i] + max[i+1] + max[i+2]) / 5
-			mean[i] = (mean[i-2] + mean[i-1] + mean[i] + mean[i+1] + mean[i+2]) / 5
+			// mean[i] = (mean[i-2] + mean[i-1] + mean[i] + mean[i+1] + mean[i+2]) / 5
+			// Reduce Median further
+			smoothRaw := []float64{float64(median[i-2]), float64(median[i-1]), float64(median[i]), float64(median[i+1]), float64(median[i+2])}
+			smoothMedian, err := util.Median(smoothRaw)
+			if err != nil {
+				median[i] = NaN
+			} else {
+				median[i] = Float(smoothMedian)
+			}
 		}
 	}
 
-	jm.StatisticsSeries = &StatsSeries{Mean: mean, Min: min, Max: max}
+	jm.StatisticsSeries = &StatsSeries{Median: median, Min: min, Max: max} // Mean: mean
 }
 
 func (jd *JobData) AddNodeScope(metric string) bool {

web/frontend/src/JobFootprint.svelte

@@ -101,7 +101,7 @@
         // Calculate Avg from jobMetrics
         const jm = jobMetrics.find((jm) => jm.name === fm && jm.scope === "node");
         if (jm?.metric?.statisticsSeries) {
-          mv = round(mean(jm.metric.statisticsSeries.mean), 2);
+          mv = round(mean(jm.metric.statisticsSeries.median), 2);
         } else if (jm?.metric?.series?.length > 1) {
           const avgs = jm.metric.series.map((jms) => jms.statistics.avg);
           mv = round(mean(avgs), 2);

web/frontend/src/Metric.svelte

@@ -33,7 +33,7 @@
     error = null;
   let selectedScope = minScope(scopes);
 
-  let statsPattern = /(.*)-stats$/
+  let statsPattern = /(.*)-stat$/
   let statsSeries = rawData.map((data) => data?.statisticsSeries ? data.statisticsSeries : null)
   let selectedScopeIndex
 
@@ -92,7 +92,7 @@
     {#each availableScopes as scope, index}
       <option value={scope}>{scope}</option>
       {#if statsSeries[index]}
-        <option value={scope + '-stats'}>stats series ({scope})</option>
+        <option value={scope + '-stat'}>stats series ({scope})</option>
       {/if}
     {/each}
     {#if availableScopes.length == 1 && metricConfig?.scope != "node"}

web/frontend/src/joblist/Row.svelte

@@ -50,7 +50,7 @@
           timestep
           statisticsSeries {
             min
-            mean
+            median
             max
           }
           series {

web/frontend/src/plots/MetricPlot.svelte

@@ -216,7 +216,7 @@
 
       // conditional hide series color markers:
       if (
-        useStatsSeries === true || // Min/Max/Avg Self-Explanatory
+        useStatsSeries === true || // Min/Max/Median Self-Explanatory
         dataSize === 1 || // Only one Y-Dataseries
         dataSize > 6
       ) {
@@ -296,7 +296,7 @@
   }
 
   const longestSeries = useStatsSeries
-    ? statisticsSeries.mean.length
+    ? statisticsSeries.median.length
     : series.reduce((n, series) => Math.max(n, series.data.length), 0);
   const maxX = longestSeries * timestep;
   let maxY = null;
@@ -346,13 +346,15 @@
   if (useStatsSeries) {
     plotData.push(statisticsSeries.min);
     plotData.push(statisticsSeries.max);
-    plotData.push(statisticsSeries.mean);
+    plotData.push(statisticsSeries.median);
+    // plotData.push(statisticsSeries.mean);
 
     if (forNode === true) {
       // timestamp 0 with null value for reversed time axis
       if (plotData[1].length != 0) plotData[1].push(null);
       if (plotData[2].length != 0) plotData[2].push(null);
       if (plotData[3].length != 0) plotData[3].push(null);
+      // if (plotData[4].length != 0) plotData[4].push(null);
     }
 
     plotSeries.push({
@@ -368,11 +370,17 @@
       stroke: "green",
     });
     plotSeries.push({
-      label: "mean",
+      label: "median",
       scale: "y",
       width: lineWidth,
       stroke: "black",
     });
+    // plotSeries.push({
+    //   label: "mean",
+    //   scale: "y",
+    //   width: lineWidth,
+    //   stroke: "blue",
+    // });
 
     plotBands = [
       { series: [2, 3], fill: "rgba(0,255,0,0.1)" },
@@ -422,7 +430,7 @@
           // Draw plot type label:
           let textl = `${scope}${plotSeries.length > 2 ? "s" : ""}${
             useStatsSeries
-              ? ": min/avg/max"
+              ? ": min/median/max"
               : metricConfig != null && scope != metricConfig.scope
                 ? ` (${metricConfig.aggregation})`
                 : ""