refactor data hist structs, add Val field

cwidgets/expanded/hist.go

@@ -1,74 +1,60 @@
 package expanded
 
 type IntHist struct {
-	data   []int
-	labels []string
+	Val    int   // most current data point
+	Data   []int // historical data points
+	Labels []string
 }
 
-func NewIntHist(max int) IntHist {
-	return IntHist{
-		data:   make([]int, max),
-		labels: make([]string, max),
+func NewIntHist(max int) *IntHist {
+	return &IntHist{
+		Data:   make([]int, max),
+		Labels: make([]string, max),
 	}
 }
 
-func (h IntHist) Append(val int) {
-	if len(h.data) == cap(h.data) {
-		h.data = append(h.data[:0], h.data[1:]...)
+func (h *IntHist) Append(val int) {
+	if len(h.Data) == cap(h.Data) {
+		h.Data = append(h.Data[:0], h.Data[1:]...)
 	}
+	h.Val = val
+	h.Data = append(h.Data, val)
+}
 
-	h.data = append(h.data, val)
+type DiffHist struct {
+	*IntHist
+	lastVal int
+}
+
+func NewDiffHist(max int) *DiffHist {
+	return &DiffHist{NewIntHist(max), -1}
+}
+
+func (h *DiffHist) Append(val int) {
+	if h.lastVal >= 0 { // skip append if this is the initial update
+		diff := val - h.lastVal
+		h.IntHist.Append(diff)
+	}
+	h.lastVal = val
 }
 
 type FloatHist struct {
-	data   []float64
-	labels []string
+	Val    float64   // most current data point
+	Data   []float64 // historical data points
+	Labels []string
 }
 
 func NewFloatHist(max int) FloatHist {
 	return FloatHist{
-		data:   make([]float64, max),
-		labels: make([]string, max),
+		Data:   make([]float64, max),
+		Labels: make([]string, max),
 	}
 }
 
 func (h FloatHist) Append(val float64) {
-	if len(h.data) == cap(h.data) {
-		h.data = append(h.data[:0], h.data[1:]...)
+	if len(h.Data) == cap(h.Data) {
+		h.Data = append(h.Data[:0], h.Data[1:]...)
 	}
-	h.data = append(h.data, val)
-}
-
-type DiffHist struct {
-	data    []int // data point derivatives
-	srcData []int // principal input data
-	labels  []string
-}
-
-func NewDiffHist(max int) DiffHist {
-	return DiffHist{
-		data:    make([]int, max),
-		srcData: make([]int, max),
-		labels:  make([]string, max),
-	}
-}
-
-// return most recent value
-func (h DiffHist) Last() int {
-	return h.data[len(h.data)-1]
-}
-
-func (h DiffHist) Append(val int) {
-	if len(h.data) == cap(h.data) {
-		h.data = append(h.data[:0], h.data[1:]...)
-	}
-	if len(h.srcData) == cap(h.srcData) {
-		h.srcData = append(h.srcData[:0], h.srcData[1:]...)
-	}
-
-	diff := val - h.srcData[len(h.srcData)-1]
-	if diff != val { // skip adding to data if this is the initial update
-		h.data = append(h.data, diff)
-	}
-	h.srcData = append(h.srcData, val)
+	h.Val = val
+	h.Data = append(h.Data, val)
 }