removed shit.

stats.go

@@ -10,34 +10,24 @@ var _ = fmt.Print
 const initialLength int = 1024
 const verySmall float64 = -100000
 const veryBig float64 = 100000
-const epsilon = 0.00000002
+
+type Stats struct {
+	Mean float64 `json:"mean"`
+	Var  float64 `json:"var"`
+	Std  float64 `json:"std"`
+}
 
 type StatAggregator struct {
 	sum             float64
 	sumOfTheSquares float64
 	n               int
-	// histogram is a list of point between [min max] each point in the
-	//histogram represents the beginning of the histogram bars.
 	histogram       []float64
-	histogramValues      []int
-	histogramBarWidth    float64
-	numberOfHistogramBar int
 	min             float64
 	max             float64
 }
 
-type Stats struct{}
-
 func NewStatAggregator() *StatAggregator {
-	return &StatAggregator{0,
-		0,
-		0,
-		make([]float64, 0, initialLength),
-		make([]int, 0, initialLength),
-		0,
-		initialLength,
-		veryBig,
-		verySmall}
+	return &StatAggregator{0, 0, 0, make([]float64, initialLength), veryBig, verySmall}
 }
 
 func (this *StatAggregator) AddStats(dataChannel chan float64, output chan *Stats) {
@@ -52,39 +42,15 @@ func (this *StatAggregator) AddStats(dataChannel chan float64, output chan *Stat
 			this.max = datum
 		}
 	}
-	output <- nil
+	output <- this.getFinalStats()
 }
 
-//  always assume the min and max includes the value!
-func (this *StatAggregator) AddDataToHistogram(value float64) {
-	if len(this.histogramValues) < this.numberOfHistogramBar {
-		this.AddDataToHistogramWhenLessDataThanBarAreOnHistograms(value)
-	} else {
-		this.AddDataToHistogramWithMaximalNumberOfBars(value)
+func (this *StatAggregator) getFinalStats() *Stats {
+	stats := new(Stats)
+	stats.Mean = this.sum / float64(this.n)
+	stats.Var = this.sumOfTheSquares/float64(this.n) - stats.Mean*stats.Mean
+	stats.Std = math.Sqrt(stats.Var)
+
+	return stats
 
 }
-
-}
-
-func (this *StatAggregator) AddDataToHistogramWithMaximalNumberOfBars(value float64) {
-}
-
-func (this *StatAggregator) AddDataToHistogramWhenLessDataThanBarAreOnHistograms(value float64) {
-	for i, v := range this.histogram {
-		if math.Abs(value-v) < epsilon {
-			this.histogramValues[i]++
-			return
-		} else if value < v {
-			this.histogram = append(this.histogram, 0)
-			copy(this.histogram[i+1:], this.histogram[i:])
-			this.histogram[i] = value
-
-			this.histogramValues = append(this.histogramValues, 0)
-			copy(this.histogramValues[i+1:], this.histogramValues[i:])
-			this.histogramValues[i] = 1
-			return
-		}
-	}
-	this.histogramValues = append(this.histogramValues, 1)
-	this.histogram = append(this.histogram, value)
-}

stats_test.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"reflect"
 	"testing"
 )
 
@@ -10,11 +9,9 @@ func TestNewStats(t *testing.T) {
 	if s.n != 0 ||
 		s.sum != 0 ||
 		s.sumOfTheSquares != 0 ||
-		s.numberOfHistogramBar != initialLength ||
+		len(s.histogram) != initialLength ||
 		s.min != veryBig ||
-		s.max != verySmall ||
-		len(s.histogram) != 0 ||
-		len(s.histogramValues) != 0 {
+		s.max != verySmall {
 		t.Fail()
 	}
 }
@@ -34,52 +31,22 @@ func TestAddStatsBasic(t *testing.T) {
 	if s.n != 4. || s.min != -1. || s.max != 20. || s.sum != 23. || s.sumOfTheSquares != 411. {
 		t.Error(">>>", s.max, s.min)
 	}
+
 }
 
-func TestAddDataToHistogramWhenLessDataThanBarAreOnHistograms(t *testing.T) {
+func TestGetFinalStats(t *testing.T) {
 	s := NewStatAggregator()
-	s.AddDataToHistogramWhenLessDataThanBarAreOnHistograms(17)
-	if !reflect.DeepEqual([]float64{17}, s.histogram) {
-		t.Error("bad histogram", s.histogram)
-	}
-	if !reflect.DeepEqual([]int{1}, s.histogramValues) {
-		t.Error("bad histogramValues:", s.histogramValues)
-	}
-	s.histogram = []float64{-1, 1, 2, 3}
-	s.histogramValues = []int{1, 1, 1, 1}
-	s.AddDataToHistogramWhenLessDataThanBarAreOnHistograms(2)
-	if !reflect.DeepEqual([]int{1, 1, 2, 1}, s.histogramValues) {
-		t.Error("bad histogramValues", s.histogramValues)
-	}
-
-	s.AddDataToHistogramWhenLessDataThanBarAreOnHistograms(2.5)
-	if !reflect.DeepEqual([]float64{-1, 1, 2, 2.5, 3}, s.histogram) {
-		t.Error("bad histogram", s.histogram)
-	}
-	if !reflect.DeepEqual([]int{1, 1, 2, 1, 1}, s.histogramValues) {
-		t.Error("bad histogramValues:", s.histogramValues)
-	}
-
-	s.AddDataToHistogramWhenLessDataThanBarAreOnHistograms(22.5)
-	if !reflect.DeepEqual([]float64{-1, 1, 2, 2.5, 3, 22.5}, s.histogram) {
-		t.Error("bad histogram", s.histogram)
-	}
-	if !reflect.DeepEqual([]int{1, 1, 2, 1, 1, 1}, s.histogramValues) {
-		t.Error("bad histogramValues:", s.histogramValues)
-	}
-
-}
-
-func TestAddDataToHistogramWithMaximalNumberOfBars(t *testing.T) {
-	s := NewStatAggregator()
-	s.numberOfHistogramBar = 5
-	s.histogram = []float64{1, 2, 3, 4, 5}
-	s.histogramValues = []int{1, 1, 2, 3, 4}
-	s.AddDataToHistogramWithMaximalNumberOfBars(3.5)
-	if !reflect.DeepEqual(s.histogram, []float64{1, 2, 3, 4, 5}) {
+	s.sumOfTheSquares = 5000
+	s.sum = 200
+	s.n = 10
+	stats := s.getFinalStats()
+	if stats.Mean != 20. {
 		t.Fail()
 	}
-	if !reflect.DeepEqual(s.histogramValues, []int{1, 1, 2, 3, 4}) {
+	if stats.Var != 100. {
+		t.Fail()
+	}
+	if stats.Std != 10. {
 		t.Fail()
 	}
 }