descending

continuous_range.go

@@ -7,9 +7,15 @@ import (
 
 // ContinuousRange represents a boundary for a set of numbers.
 type ContinuousRange struct {
-	Min    float64
-	Max    float64
-	Domain int
+	Min        float64
+	Max        float64
+	Domain     int
+	Descending bool
+}
+
+// IsDescending returns if the range is descending.
+func (r ContinuousRange) IsDescending() bool {
+	return r.Descending
 }
 
 // IsZero returns if the ContinuousRange has been set or not.
@@ -56,12 +62,17 @@ func (r *ContinuousRange) SetDomain(domain int) {
 
 // String returns a simple string for the ContinuousRange.
 func (r ContinuousRange) String() string {
-	return fmt.Sprintf("ContinuousRange [%.2f,%.2f] => %f", r.Min, r.Max, r.Domain)
+	return fmt.Sprintf("ContinuousRange [%.2f,%.2f] => %d", r.Min, r.Max, r.Domain)
 }
 
 // Translate maps a given value into the ContinuousRange space.
 func (r ContinuousRange) Translate(value float64) int {
 	normalized := value - r.Min
 	ratio := normalized / r.GetDelta()
+
+	if r.IsDescending() {
+		return r.Domain - int(math.Ceil(ratio*float64(r.Domain)))
+	}
+
 	return int(math.Ceil(ratio * float64(r.Domain)))
 }