adding jet as a generator
This commit is contained in:
parent
c599f1a2a2
commit
3f046bbba1
|
@ -17,7 +17,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
|
||||||
Show: true,
|
Show: true,
|
||||||
StrokeWidth: chart.Disabled,
|
StrokeWidth: chart.Disabled,
|
||||||
DotWidth: 5,
|
DotWidth: 5,
|
||||||
DotColorProvider: chart.Viridis,
|
DotColorProvider: chart.Jet,
|
||||||
},
|
},
|
||||||
XValues: chart.Sequence.Random(128, 1024),
|
XValues: chart.Sequence.Random(128, 1024),
|
||||||
YValues: chart.Sequence.Random(128, 1024),
|
YValues: chart.Sequence.Random(128, 1024),
|
||||||
|
|
|
@ -57,6 +57,11 @@ func ColorFromAlphaMixedRGBA(r, g, b, a uint32) Color {
|
||||||
return c
|
return c
|
||||||
}
|
}
|
||||||
|
|
||||||
|
// ColorChannelFromFloat returns a normalized byte from a given float value.
|
||||||
|
func ColorChannelFromFloat(v float64) uint8 {
|
||||||
|
return uint8(v * 255)
|
||||||
|
}
|
||||||
|
|
||||||
// Color is our internal color type because color.Color is bullshit.
|
// Color is our internal color type because color.Color is bullshit.
|
||||||
type Color struct {
|
type Color struct {
|
||||||
R, G, B, A uint8
|
R, G, B, A uint8
|
||||||
|
|
37
jet.go
Normal file
37
jet.go
Normal file
|
@ -0,0 +1,37 @@
|
||||||
|
package chart
|
||||||
|
|
||||||
|
import "github.com/wcharczuk/go-chart/drawing"
|
||||||
|
|
||||||
|
// Jet is a color map provider based on matlab's jet color map.
|
||||||
|
func Jet(xr, yr Range, x, y float64) drawing.Color {
|
||||||
|
return getJetColour(y, yr.GetMin(), yr.GetMax())
|
||||||
|
}
|
||||||
|
|
||||||
|
func getJetColour(v, vmin, vmax float64) drawing.Color {
|
||||||
|
c := drawing.Color{R: 0xff, G: 0xff, B: 0xff, A: 0xff} // white
|
||||||
|
var dv float64
|
||||||
|
|
||||||
|
if v < vmin {
|
||||||
|
v = vmin
|
||||||
|
}
|
||||||
|
if v > vmax {
|
||||||
|
v = vmax
|
||||||
|
}
|
||||||
|
dv = vmax - vmin
|
||||||
|
|
||||||
|
if v < (vmin + 0.25*dv) {
|
||||||
|
c.R = 0
|
||||||
|
c.G = drawing.ColorChannelFromFloat(4 * (v - vmin) / dv)
|
||||||
|
} else if v < (vmin + 0.5*dv) {
|
||||||
|
c.R = 0
|
||||||
|
c.B = drawing.ColorChannelFromFloat(1 + 4*(vmin+0.25*dv-v)/dv)
|
||||||
|
} else if v < (vmin + 0.75*dv) {
|
||||||
|
c.R = drawing.ColorChannelFromFloat(4 * (v - vmin - 0.5*dv) / dv)
|
||||||
|
c.B = 0
|
||||||
|
} else {
|
||||||
|
c.G = drawing.ColorChannelFromFloat(1 + 4*(vmin+0.75*dv-v)/dv)
|
||||||
|
c.B = 0
|
||||||
|
}
|
||||||
|
|
||||||
|
return c
|
||||||
|
}
|
Loading…
Reference in New Issue
Block a user