axis tick position

annotation_series.go

@@ -6,7 +6,7 @@ import "math"
 type AnnotationSeries struct {
 	Name        string
 	Style       Style
-	YAxis       YAxisType
+	YAxis       yAxisType
 	Annotations []Value2
 }
 
@@ -21,7 +21,7 @@ func (as AnnotationSeries) GetStyle() Style {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (as AnnotationSeries) GetYAxis() YAxisType {
+func (as AnnotationSeries) GetYAxis() yAxisType {
 	return as.YAxis
 }
 

axis.go

@@ -1,13 +1,24 @@
 package chart
 
+type tickPosition int
+
+const (
+	// TickPositionUnset means to use the default tick position.
+	TickPositionUnset tickPosition = 0
+	// TickPositionBetweenTicks draws the labels for a tick between the previous and current tick.
+	TickPositionBetweenTicks tickPosition = 1
+	// TickPositionUnderTick draws the tick below the tick.
+	TickPositionUnderTick tickPosition = 2
+)
+
 // YAxisType is a type of y-axis; it can either be primary or secondary.
-type YAxisType int
+type yAxisType int
 
 const (
 	// YAxisPrimary is the primary axis.
-	YAxisPrimary YAxisType = 0
+	YAxisPrimary yAxisType = 0
 	// YAxisSecondary is the secondary axis.
-	YAxisSecondary YAxisType = 1
+	YAxisSecondary yAxisType = 1
 )
 
 // Axis is a chart feature detailing what values happen where.

bollinger_band_series.go

@@ -7,7 +7,7 @@ import "math"
 type BollingerBandsSeries struct {
 	Name  string
 	Style Style
-	YAxis YAxisType
+	YAxis yAxisType
 
 	Period      int
 	K           float64
@@ -27,7 +27,7 @@ func (bbs BollingerBandsSeries) GetStyle() Style {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (bbs BollingerBandsSeries) GetYAxis() YAxisType {
+func (bbs BollingerBandsSeries) GetYAxis() yAxisType {
 	return bbs.YAxis
 }
 

continuous_series.go

@@ -5,7 +5,7 @@ type ContinuousSeries struct {
 	Name  string
 	Style Style
 
-	YAxis YAxisType
+	YAxis yAxisType
 
 	XValues []float64
 	YValues []float64
@@ -44,7 +44,7 @@ func (cs ContinuousSeries) GetValueFormatters() (x, y ValueFormatter) {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (cs ContinuousSeries) GetYAxis() YAxisType {
+func (cs ContinuousSeries) GetYAxis() yAxisType {
 	return cs.YAxis
 }
 

draw.go

@@ -62,8 +62,6 @@ func (d draw) BoundedSeries(r Renderer, canvasBox Box, xrange, yrange Range, sty
 		drawOffsetIndex = drawOffsetIndexes[0]
 	}
 
-	style.WriteToRenderer(r)
-
 	cb := canvasBox.Bottom
 	cl := canvasBox.Left
 
@@ -79,6 +77,7 @@ func (d draw) BoundedSeries(r Renderer, canvasBox Box, xrange, yrange Range, sty
 	y2values := make([]float64, bbs.Len())
 	y2values[0] = v0y2
 
+	style.GetFillAndStrokeOptions().WriteToRenderer(r)
 	r.MoveTo(x0, y0)
 	for i := 1; i < bbs.Len(); i++ {
 		vx, vy1, vy2 = bbs.GetBoundedValue(i)

ema_series.go

@@ -9,7 +9,7 @@ const (
 type EMASeries struct {
 	Name  string
 	Style Style
-	YAxis YAxisType
+	YAxis yAxisType
 
 	Period      int
 	InnerSeries ValueProvider
@@ -28,7 +28,7 @@ func (ema EMASeries) GetStyle() Style {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (ema EMASeries) GetYAxis() YAxisType {
+func (ema EMASeries) GetYAxis() yAxisType {
 	return ema.YAxis
 }
 

examples/stock_analysis/main.go

@@ -43,7 +43,8 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	graph := chart.Chart{
 		XAxis: chart.XAxis{
-			Style: chart.Style{Show: true},
+			Style:        chart.Style{Show: true},
+			TickPosition: chart.TickPositionBetweenTicks,
 		},
 		YAxis: chart.YAxis{
 			Style: chart.Style{Show: true},

histogram_series.go

@@ -6,7 +6,7 @@ package chart
 type HistogramSeries struct {
 	Name        string
 	Style       Style
-	YAxis       YAxisType
+	YAxis       yAxisType
 	InnerSeries ValueProvider
 }
 
@@ -21,7 +21,7 @@ func (hs HistogramSeries) GetStyle() Style {
 }
 
 // GetYAxis returns which yaxis the series is mapped to.
-func (hs HistogramSeries) GetYAxis() YAxisType {
+func (hs HistogramSeries) GetYAxis() yAxisType {
 	return hs.YAxis
 }
 

linear_regression_series.go

@@ -5,7 +5,7 @@ package chart
 type LinearRegressionSeries struct {
 	Name  string
 	Style Style
-	YAxis YAxisType
+	YAxis yAxisType
 
 	Window      int
 	Offset      int
@@ -28,7 +28,7 @@ func (lrs LinearRegressionSeries) GetStyle() Style {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (lrs LinearRegressionSeries) GetYAxis() YAxisType {
+func (lrs LinearRegressionSeries) GetYAxis() yAxisType {
 	return lrs.YAxis
 }
 

macd_series.go

@@ -14,7 +14,7 @@ const (
 type MACDSeries struct {
 	Name        string
 	Style       Style
-	YAxis       YAxisType
+	YAxis       yAxisType
 	InnerSeries ValueProvider
 
 	PrimaryPeriod   int
@@ -56,7 +56,7 @@ func (macd MACDSeries) GetStyle() Style {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (macd MACDSeries) GetYAxis() YAxisType {
+func (macd MACDSeries) GetYAxis() yAxisType {
 	return macd.YAxis
 }
 
@@ -109,7 +109,7 @@ func (macd *MACDSeries) ensureChildSeries() {
 type MACDSignalSeries struct {
 	Name        string
 	Style       Style
-	YAxis       YAxisType
+	YAxis       yAxisType
 	InnerSeries ValueProvider
 
 	PrimaryPeriod   int
@@ -150,7 +150,7 @@ func (macds MACDSignalSeries) GetStyle() Style {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (macds MACDSignalSeries) GetYAxis() YAxisType {
+func (macds MACDSignalSeries) GetYAxis() yAxisType {
 	return macds.YAxis
 }
 
@@ -200,7 +200,7 @@ func (macds *MACDSignalSeries) Render(r Renderer, canvasBox Box, xrange, yrange
 type MACDLineSeries struct {
 	Name        string
 	Style       Style
-	YAxis       YAxisType
+	YAxis       yAxisType
 	InnerSeries ValueProvider
 
 	PrimaryPeriod   int
@@ -223,7 +223,7 @@ func (macdl MACDLineSeries) GetStyle() Style {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (macdl MACDLineSeries) GetYAxis() YAxisType {
+func (macdl MACDLineSeries) GetYAxis() yAxisType {
 	return macdl.YAxis
 }
 

series.go

@@ -3,7 +3,7 @@ package chart
 // Series is an alias to Renderable.
 type Series interface {
 	GetName() string
-	GetYAxis() YAxisType
+	GetYAxis() yAxisType
 	GetStyle() Style
 	Render(r Renderer, canvasBox Box, xrange, yrange Range, s Style)
 }

sma_series.go

@@ -9,7 +9,7 @@ const (
 type SMASeries struct {
 	Name  string
 	Style Style
-	YAxis YAxisType
+	YAxis yAxisType
 
 	Period      int
 	InnerSeries ValueProvider
@@ -26,7 +26,7 @@ func (sma SMASeries) GetStyle() Style {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (sma SMASeries) GetYAxis() YAxisType {
+func (sma SMASeries) GetYAxis() yAxisType {
 	return sma.YAxis
 }
 

time_series.go

@@ -7,7 +7,7 @@ type TimeSeries struct {
 	Name  string
 	Style Style
 
-	YAxis YAxisType
+	YAxis yAxisType
 
 	XValues []time.Time
 	YValues []float64
@@ -50,7 +50,7 @@ func (ts TimeSeries) GetValueFormatters() (x, y ValueFormatter) {
 }
 
 // GetYAxis returns which YAxis the series draws on.
-func (ts TimeSeries) GetYAxis() YAxisType {
+func (ts TimeSeries) GetYAxis() yAxisType {
 	return ts.YAxis
 }
 

xaxis.go

@@ -13,6 +13,8 @@ type XAxis struct {
 	Range          Range
 	Ticks          []Tick
 
+	TickPosition tickPosition
+
 	GridLines      []GridLine
 	GridMajorStyle Style
 	GridMinorStyle Style
@@ -28,6 +30,17 @@ func (xa XAxis) GetStyle() Style {
 	return xa.Style
 }
 
+// GetTickPosition returns the tick position option for the axis.
+func (xa XAxis) GetTickPosition(defaults ...tickPosition) tickPosition {
+	if xa.TickPosition == TickPositionUnset {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return TickPositionUnderTick
+	}
+	return xa.TickPosition
+}
+
 // GetTicks returns the ticks for a series.
 // The coalesce priority is:
 // 	- User Supplied Ticks (i.e. Ticks array on the axis itself).
@@ -82,25 +95,48 @@ func (xa XAxis) Measure(r Renderer, canvasBox Box, ra Range, defaults Style, tic
 
 // Render renders the axis
 func (xa XAxis) Render(r Renderer, canvasBox Box, ra Range, defaults Style, ticks []Tick) {
-	xa.Style.InheritFrom(defaults).WriteToRenderer(r)
+	tickStyle := xa.Style.InheritFrom(defaults)
 
+	tickStyle.GetStrokeOptions().WriteToRenderer(r)
 	r.MoveTo(canvasBox.Left, canvasBox.Bottom)
 	r.LineTo(canvasBox.Right, canvasBox.Bottom)
 	r.Stroke()
 
 	sort.Sort(Ticks(ticks))
 
-	for _, t := range ticks {
+	tp := xa.GetTickPosition()
+
+	var tx, ty int
+	for index, t := range ticks {
 		v := t.Value
 		lx := ra.Translate(v)
 		tb := r.MeasureText(t.Label)
-		tx := canvasBox.Left + lx
-		ty := canvasBox.Bottom + DefaultXAxisMargin + tb.Height()
-		r.Text(t.Label, tx-tb.Width()>>1, ty)
 
+		tx = canvasBox.Left + lx
+		ty = canvasBox.Bottom + DefaultXAxisMargin + tb.Height()
+
+		tickStyle.GetStrokeOptions().WriteToRenderer(r)
 		r.MoveTo(tx, canvasBox.Bottom)
 		r.LineTo(tx, canvasBox.Bottom+DefaultVerticalTickHeight)
 		r.Stroke()
+
+		switch tp {
+		case TickPositionUnderTick:
+			tickStyle.GetTextOptions().WriteToRenderer(r)
+			r.Text(t.Label, tx-tb.Width()>>1, ty)
+		case TickPositionBetweenTicks:
+			if index > 0 {
+				llx := ra.Translate(ticks[index-1].Value)
+				ltx := canvasBox.Left + llx
+				Draw.TextWithin(r, t.Label, Box{
+					Left:   ltx,
+					Right:  tx,
+					Top:    canvasBox.Bottom + DefaultXAxisMargin,
+					Bottom: canvasBox.Bottom + DefaultXAxisMargin + tb.Height(),
+				}, tickStyle.InheritFrom(Style{TextHorizontalAlign: TextHorizontalAlignCenter}))
+			}
+		}
+
 	}
 
 	if xa.GridMajorStyle.Show || xa.GridMinorStyle.Show {

yaxis.go

@@ -13,7 +13,7 @@ type YAxis struct {
 
 	Zero GridLine
 
-	AxisType YAxisType
+	AxisType yAxisType
 
 	ValueFormatter ValueFormatter
 	Range          Range