histogram still needs tweaking.
This commit is contained in:
parent
d455b775da
commit
7858457772
4 changed files with 233 additions and 1 deletions
|
@ -1,6 +1,10 @@
|
|||
package chart
|
||||
|
||||
import "github.com/wcharczuk/go-chart/drawing"
|
||||
import (
|
||||
"math"
|
||||
|
||||
"github.com/wcharczuk/go-chart/drawing"
|
||||
)
|
||||
|
||||
// DrawLineSeries draws a line series with a renderer.
|
||||
func DrawLineSeries(r Renderer, canvasBox Box, xrange, yrange Range, s Style, vs ValueProvider) {
|
||||
|
@ -102,6 +106,38 @@ func DrawBoundedSeries(r Renderer, canvasBox Box, xrange, yrange Range, s Style,
|
|||
r.FillStroke()
|
||||
}
|
||||
|
||||
// DrawHistogramSeries draws a value provider as boxes from 0.
|
||||
func DrawHistogramSeries(r Renderer, canvasBox Box, xrange, yrange Range, s Style, vs ValueProvider, barWidths ...int) {
|
||||
if vs.Len() == 0 {
|
||||
return
|
||||
}
|
||||
|
||||
//calculate bar width?
|
||||
seriesLength := vs.Len()
|
||||
barWidth := int(math.Floor(float64(xrange.Domain) / float64(seriesLength)))
|
||||
if len(barWidths) > 0 {
|
||||
barWidth = barWidths[0]
|
||||
}
|
||||
|
||||
cb := canvasBox.Bottom
|
||||
cl := canvasBox.Left
|
||||
|
||||
//foreach datapoint, draw a box.
|
||||
for index := 0; index < seriesLength; index++ {
|
||||
vx, vy := vs.GetValue(index)
|
||||
y0 := yrange.Translate(0)
|
||||
x := cl + xrange.Translate(vx)
|
||||
y := yrange.Translate(vy)
|
||||
|
||||
DrawBox(r, Box{
|
||||
Top: cb - y0,
|
||||
Left: x - (barWidth >> 1),
|
||||
Right: x + (barWidth >> 1),
|
||||
Bottom: cb - y,
|
||||
}, s)
|
||||
}
|
||||
}
|
||||
|
||||
// MeasureAnnotation measures how big an annotation would be.
|
||||
func MeasureAnnotation(r Renderer, canvasBox Box, s Style, lx, ly int, label string) Box {
|
||||
r.SetFillColor(s.GetFillColor(DefaultAnnotationFillColor))
|
||||
|
|
57
histogram_series.go
Normal file
57
histogram_series.go
Normal file
|
@ -0,0 +1,57 @@
|
|||
package chart
|
||||
|
||||
// HistogramSeries is a special type of series that draws as a histogram.
|
||||
// Some peculiarities; it will always be lower bounded at 0 (at the very least).
|
||||
// This may alter ranges a bit and generally you want to put a histogram series on it's own y-axis.
|
||||
type HistogramSeries struct {
|
||||
Name string
|
||||
Style Style
|
||||
YAxis YAxisType
|
||||
InnerSeries ValueProvider
|
||||
}
|
||||
|
||||
// GetName implements Series.GetName.
|
||||
func (hs HistogramSeries) GetName() string {
|
||||
return hs.Name
|
||||
}
|
||||
|
||||
// GetStyle implements Series.GetStyle.
|
||||
func (hs HistogramSeries) GetStyle() Style {
|
||||
return hs.Style
|
||||
}
|
||||
|
||||
// GetYAxis returns which yaxis the series is mapped to.
|
||||
func (hs HistogramSeries) GetYAxis() YAxisType {
|
||||
return hs.YAxis
|
||||
}
|
||||
|
||||
// Len implements BoundedValueProvider.Len.
|
||||
func (hs HistogramSeries) Len() int {
|
||||
return hs.InnerSeries.Len()
|
||||
}
|
||||
|
||||
// GetValue implements ValueProvider.GetValue.
|
||||
func (hs HistogramSeries) GetValue(index int) (x, y float64) {
|
||||
return hs.InnerSeries.GetValue(index)
|
||||
}
|
||||
|
||||
// GetBoundedValue implements BoundedValueProvider.GetBoundedValue
|
||||
func (hs HistogramSeries) GetBoundedValue(index int) (x, y1, y2 float64) {
|
||||
vx, vy := hs.InnerSeries.GetValue(index)
|
||||
|
||||
x = vx
|
||||
|
||||
if vy > 0 {
|
||||
y1 = vy
|
||||
return
|
||||
}
|
||||
|
||||
y2 = vy
|
||||
return
|
||||
}
|
||||
|
||||
// Render implements Series.Render.
|
||||
func (hs HistogramSeries) Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) {
|
||||
style := hs.Style.WithDefaultsFrom(defaults)
|
||||
DrawHistogramSeries(r, canvasBox, xrange, yrange, style, hs)
|
||||
}
|
110
macd_series.go
Normal file
110
macd_series.go
Normal file
|
@ -0,0 +1,110 @@
|
|||
package chart
|
||||
|
||||
const (
|
||||
// DefaultMACDWindowPrimary is the long window.
|
||||
DefaultMACDWindowPrimary = 26
|
||||
// DefaultMACDWindowSecondary is the short window.
|
||||
DefaultMACDWindowSecondary = 12
|
||||
)
|
||||
|
||||
// MACDSeries (or Moving Average Convergence Divergence) is a special type of series that
|
||||
// computes the difference between two different EMA values for a given index, as denoted by WindowPrimary(26) and WindowSecondary(12).
|
||||
type MACDSeries struct {
|
||||
Name string
|
||||
Style Style
|
||||
YAxis YAxisType
|
||||
InnerSeries ValueProvider
|
||||
|
||||
WindowPrimary int
|
||||
WindowSecondary int
|
||||
|
||||
Sigma float64
|
||||
}
|
||||
|
||||
// GetWindows returns the primary and secondary window sizes.
|
||||
func (macd MACDSeries) GetWindows() (w1, w2 int) {
|
||||
if macd.WindowPrimary == 0 {
|
||||
w1 = DefaultMACDWindowPrimary
|
||||
} else {
|
||||
w1 = macd.WindowPrimary
|
||||
}
|
||||
if macd.WindowSecondary == 0 {
|
||||
w2 = DefaultMACDWindowSecondary
|
||||
} else {
|
||||
w2 = macd.WindowSecondary
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// GetSigma returns the smoothing factor for the serise.
|
||||
func (macd MACDSeries) GetSigma(defaults ...float64) float64 {
|
||||
if macd.Sigma == 0 {
|
||||
if len(defaults) > 0 {
|
||||
return defaults[0]
|
||||
}
|
||||
return DefaultExponentialMovingAverageSigma
|
||||
}
|
||||
return macd.Sigma
|
||||
}
|
||||
|
||||
// GetName returns the name of the time series.
|
||||
func (macd MACDSeries) GetName() string {
|
||||
return macd.Name
|
||||
}
|
||||
|
||||
// GetStyle returns the line style.
|
||||
func (macd MACDSeries) GetStyle() Style {
|
||||
return macd.Style
|
||||
}
|
||||
|
||||
// GetYAxis returns which YAxis the series draws on.
|
||||
func (macd MACDSeries) GetYAxis() YAxisType {
|
||||
return macd.YAxis
|
||||
}
|
||||
|
||||
// Len returns the number of elements in the series.
|
||||
func (macd MACDSeries) Len() int {
|
||||
if macd.InnerSeries == nil {
|
||||
return 0
|
||||
}
|
||||
|
||||
w1, _ := macd.GetWindows()
|
||||
innerLen := macd.InnerSeries.Len()
|
||||
if innerLen > w1 {
|
||||
return innerLen - w1
|
||||
}
|
||||
return 0
|
||||
}
|
||||
|
||||
// GetValue gets a value at a given index.
|
||||
func (macd MACDSeries) GetValue(index int) (x float64, y float64) {
|
||||
if macd.InnerSeries == nil {
|
||||
return
|
||||
}
|
||||
|
||||
w1, w2 := macd.GetWindows()
|
||||
|
||||
effectiveIndex := index + w1
|
||||
x, _ = macd.InnerSeries.GetValue(effectiveIndex)
|
||||
|
||||
ema1 := macd.computeEMA(w1, effectiveIndex)
|
||||
ema2 := macd.computeEMA(w2, effectiveIndex)
|
||||
|
||||
y = ema1 - ema2
|
||||
return
|
||||
}
|
||||
|
||||
func (macd MACDSeries) computeEMA(windowSize int, index int) float64 {
|
||||
_, v := macd.InnerSeries.GetValue(index)
|
||||
if windowSize == 1 {
|
||||
return v
|
||||
}
|
||||
sig := macd.GetSigma()
|
||||
return sig*v + ((1.0 - sig) * macd.computeEMA(windowSize-1, index-1))
|
||||
}
|
||||
|
||||
// Render renders the series.
|
||||
func (macd MACDSeries) Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) {
|
||||
style := macd.Style.WithDefaultsFrom(defaults)
|
||||
DrawLineSeries(r, canvasBox, xrange, yrange, style, macd)
|
||||
}
|
29
macd_series_test.go
Normal file
29
macd_series_test.go
Normal file
|
@ -0,0 +1,29 @@
|
|||
package chart
|
||||
|
||||
import (
|
||||
"testing"
|
||||
|
||||
"github.com/blendlabs/go-assert"
|
||||
)
|
||||
|
||||
func TestMACDSeries(t *testing.T) {
|
||||
assert := assert.New(t)
|
||||
|
||||
mockSeries := mockValueProvider{
|
||||
Seq(1.0, 100.0),
|
||||
SeqRand(100.0, 256),
|
||||
}
|
||||
assert.Equal(100, mockSeries.Len())
|
||||
|
||||
mas := &MACDSeries{
|
||||
InnerSeries: mockSeries,
|
||||
}
|
||||
|
||||
var yvalues []float64
|
||||
for x := 0; x < mas.Len(); x++ {
|
||||
_, y := mas.GetValue(x)
|
||||
yvalues = append(yvalues, y)
|
||||
}
|
||||
|
||||
assert.NotEmpty(yvalues)
|
||||
}
|
Loading…
Reference in a new issue