Adding upstream version 2.1.2.

Signed-off-by: Daniel Baumann <daniel@debian.org>

random_sequence.go

@@ -0,0 +1,92 @@
+package chart
+
+import (
+	"math"
+	"math/rand"
+	"time"
+)
+
+var (
+	_ Sequence = (*RandomSeq)(nil)
+)
+
+// RandomValues returns an array of random values.
+func RandomValues(count int) []float64 {
+	return Seq{NewRandomSequence().WithLen(count)}.Values()
+}
+
+// RandomValuesWithMax returns an array of random values with a given average.
+func RandomValuesWithMax(count int, max float64) []float64 {
+	return Seq{NewRandomSequence().WithMax(max).WithLen(count)}.Values()
+}
+
+// NewRandomSequence creates a new random seq.
+func NewRandomSequence() *RandomSeq {
+	return &RandomSeq{
+		rnd: rand.New(rand.NewSource(time.Now().Unix())),
+	}
+}
+
+// RandomSeq is a random number seq generator.
+type RandomSeq struct {
+	rnd *rand.Rand
+	max *float64
+	min *float64
+	len *int
+}
+
+// Len returns the number of elements that will be generated.
+func (r *RandomSeq) Len() int {
+	if r.len != nil {
+		return *r.len
+	}
+	return math.MaxInt32
+}
+
+// GetValue returns the value.
+func (r *RandomSeq) GetValue(_ int) float64 {
+	if r.min != nil && r.max != nil {
+		var delta float64
+
+		if *r.max > *r.min {
+			delta = *r.max - *r.min
+		} else {
+			delta = *r.min - *r.max
+		}
+
+		return *r.min + (r.rnd.Float64() * delta)
+	} else if r.max != nil {
+		return r.rnd.Float64() * *r.max
+	} else if r.min != nil {
+		return *r.min + (r.rnd.Float64())
+	}
+	return r.rnd.Float64()
+}
+
+// WithLen sets a maximum len
+func (r *RandomSeq) WithLen(length int) *RandomSeq {
+	r.len = &length
+	return r
+}
+
+// Min returns the minimum value.
+func (r RandomSeq) Min() *float64 {
+	return r.min
+}
+
+// WithMin sets the scale and returns the Random.
+func (r *RandomSeq) WithMin(min float64) *RandomSeq {
+	r.min = &min
+	return r
+}
+
+// Max returns the maximum value.
+func (r RandomSeq) Max() *float64 {
+	return r.max
+}
+
+// WithMax sets the average and returns the Random.
+func (r *RandomSeq) WithMax(max float64) *RandomSeq {
+	r.max = &max
+	return r
+}