// WritePNG renders plot to a png file of size width x height.
func (p *Plot) WritePNG(filename string, width, height vg.Length) error {
file, err := os.Create(filename)
if err != nil {
return err
}
defer file.Close()
canvas := vgimg.PngCanvas{Canvas: vgimg.New(width, height)}
canvas.Translate(-width/2, -height/2)
p.DumpTo(canvas, width, height)
canvas.WriteTo(file)
return nil
}
func TestIndividualSteps(t *testing.T) {
aes := AesMapping{
"x": "Height",
"y": "Weight",
}
plot, err := NewPlot(measurement, aes)
if err != nil {
t.Fatalf("Unxpected error: %s", err)
}
//
// Add layers to plot
//
rawData := Layer{
Name: "Raw Data",
Stat: nil, // identity
Geom: GeomPoint{
Style: AesMapping{
"color": "red",
"shape": "diamond",
}}}
plot.Layers = append(plot.Layers, &rawData)
linReg := Layer{
Name: "Linear regression",
Stat: &StatLinReq{},
Geom: GeomABLine{
Style: AesMapping{
"color": "green",
"linetype": "dashed",
},
},
// StatLinReq produces intercept/slope suitable for GeomABLine
GeomMapping: nil,
}
plot.Layers = append(plot.Layers, &linReg)
ageLabel := Layer{
Name: "Age Label",
DataMapping: AesMapping{
"value": "Age",
},
Stat: &StatLabel{Format: "%.0f years"},
Geom: GeomText{
Style: AesMapping{
"color": "blue",
"angle": "0.7", // "45°", // TODO: parsing ° fails
"family": "Helvetica",
"size": "10", // TODO: should come from DefaultTheme
},
},
GeomMapping: nil,
}
plot.Layers = append(plot.Layers, &ageLabel)
histogram := Layer{
Name: "Histogram",
DataMapping: AesMapping{"y": ""}, // clear mapping of y to Height
Stat: &StatBin{Drop: true},
StatMapping: AesMapping{
"y": "count",
},
Geom: GeomBar{
Style: AesMapping{
"fill": "gray50",
},
},
}
plot.Layers = append(plot.Layers, &histogram)
// Set up the one panel.
plot.CreatePanels()
if len(plot.Panels) != 1 {
t.Fatalf("Got %d panel rows, expected 1.", len(plot.Panels))
}
if len(plot.Panels[0]) != 1 {
t.Fatalf("Got %d panel cols, expected 1.", len(plot.Panels[0]))
}
panel := plot.Panels[0][0]
// 2. PrepareData
panel.PrepareData()
if fields := panel.Layers[0].Data.FieldNames(); !same(fields, []string{"x", "y"}) {
t.Errorf("Layer 0 DF has fields %v", fields)
}
if fields := panel.Layers[1].Data.FieldNames(); !same(fields, []string{"x", "y"}) {
t.Errorf("Layer 1 DF has fields %v", fields)
}
if sx, ok := panel.Scales["x"]; !ok {
t.Errorf("Missing x scale")
} else {
if sx.Discrete || sx.Transform != &IdentityScale || sx.Aesthetic != "x" {
t.Errorf("Scale x = %+v", sx)
}
}
if sy, ok := panel.Scales["y"]; !ok {
t.Errorf("Missing y scale")
} else {
if sy.Discrete || sy.Transform != &IdentityScale || sy.Aesthetic != "y" {
t.Errorf("Scale y = %+v", sy)
}
}
// 3. ComputeStatistics
panel.ComputeStatistics()
// No statistic on layer 0: data field is unchanges
if fields := panel.Layers[0].Data.FieldNames(); !same(fields, []string{"x", "y"}) {
t.Errorf("Layer 0 DF has fields %v", fields)
}
// StatLinReq produces intercept and slope
if fields := panel.Layers[1].Data.FieldNames(); !same(fields, []string{"intercept", "slope", "interceptErr", "slopeErr"}) {
t.Errorf("Layer 1 DF has fields %v", fields)
}
data := panel.Layers[1].Data
if data.N != 1 {
t.Errorf("Got %d data in lin req df.", panel.Layers[1].Data.N)
}
t.Logf("Intercept = %.2f Slope = %.2f",
data.Columns["intercept"].Data[0],
data.Columns["slope"].Data[0])
// StatLabels produces labels
if fields := panel.Layers[2].Data.FieldNames(); !same(fields, []string{"x", "y", "text"}) {
t.Errorf("Layer 2 %q has fields %v", panel.Layers[3].Name, fields)
}
data = panel.Layers[2].Data
if data.N != 20 {
t.Errorf("Got %d data in label df.", panel.Layers[2].Data.N)
}
// StatBin produces bins
if fields := panel.Layers[3].Data.FieldNames(); !same(fields, []string{"x", "count", "ncount", "density", "ndensity"}) {
t.Errorf("Layer 3 %q has fields %v", panel.Layers[3].Name, fields)
}
data = panel.Layers[3].Data
if data.N != 11 {
t.Errorf("Got %d data in binned df.", panel.Layers[3].Data.N)
}
// 4. Wireing
panel.WireStatToGeom()
for a, s := range panel.Scales {
fmt.Printf("====== Scale %s %q ========\n", a, s.Name)
fmt.Printf("%s\n", s.String())
}
// 5. Test Construct ConstructGeoms. This shouldn't change much as
// GeomABLine doesn't reparametrize and we don't do position adjustments.
panel.ConstructGeoms()
// 6. FinalizeScales
panel.FinalizeScales()
// Only x and y are set up
if sx, ok := panel.Scales["x"]; !ok {
t.Errorf("Missing x scale")
} else {
if sx.Pos == nil {
t.Errorf("Missing Pos for x scale.")
}
if sx.DomainMin > 1.62 || sx.DomainMax < 1.95 {
t.Errorf("Bad training: %f %f", sx.DomainMin, sx.DomainMax)
}
}
fmt.Printf("%s\n", panel.Scales["x"])
fmt.Printf("%s\n", panel.Scales["y"])
// 7. Render Geoms to Grobs using scales (Step7).
panel.RenderGeoms()
fmt.Println("Layer 0, raw data")
for _, grob := range panel.Layers[0].Grobs {
fmt.Println(" ", grob.String())
}
fmt.Println("Layer 1, linear regression")
for _, grob := range panel.Layers[1].Grobs {
fmt.Println(" ", grob.String())
}
fmt.Println("Layer 2, labels")
for _, grob := range panel.Layers[2].Grobs {
fmt.Println(" ", grob.String())
}
fmt.Println("Layer 3, histogram")
for _, grob := range panel.Layers[3].Grobs {
fmt.Println(" ", grob.String())
}
// Output
pngCanvas := vgimg.PngCanvas{Canvas: vgimg.New(800, 600)}
pngCanvas.Translate(-400, -300)
vp := Viewport{
X0: 50,
Y0: 50,
Width: 700,
Height: 500,
Canvas: pngCanvas,
}
file, err := os.Create("example.png")
if err != nil {
t.Fatalf("%", err)
}
panel.Draw(vp, true, true)
if false {
fmt.Println("Layer 0, raw data")
for _, grob := range panel.Layers[0].Grobs {
grob.Draw(vp)
}
fmt.Println("Layer 1, linear regression")
for _, grob := range panel.Layers[1].Grobs {
grob.Draw(vp)
}
fmt.Println("Layer 2, labels")
for _, grob := range panel.Layers[2].Grobs {
grob.Draw(vp)
}
fmt.Println("Layer 3, histogram")
for _, grob := range panel.Layers[3].Grobs {
grob.Draw(vp)
}
}
pngCanvas.WriteTo(file)
file.Close()
}
func TestGraphicGrobs(t *testing.T) {
// Output
file, err := os.Create("grobs.png")
if err != nil {
t.Fatalf("%", err)
}
pngCanvas := vgimg.PngCanvas{Canvas: vgimg.New(10*vg.Inch, 8*vg.Inch)}
vg.Initialize(pngCanvas)
pngCanvas.Translate(-5*vg.Inch, -4*vg.Inch)
dot := func(x, y float64) {
pngCanvas.Push()
pngCanvas.SetColor(BuiltinColors["red"])
pngCanvas.SetLineWidth(5)
var p vg.Path
xr := vg.Length(x) * vg.Inch
yr := vg.Length(y) * vg.Inch
p.Move(xr-5, yr-5)
p.Line(xr-5, yr+5)
p.Line(xr+5, yr+5)
p.Line(xr+5, yr-5)
p.Close()
pngCanvas.Fill(p)
pngCanvas.Pop()
}
dot(0, 0)
dot(5, 0)
dot(0, 4)
allVP := Viewport{
X0: 0,
Y0: 0,
Width: 10 * vg.Inch,
Height: 8 * vg.Inch,
Canvas: pngCanvas,
}
innerVP := allVP.Sub(0.05, 0.05, 0.9, 0.9)
bg := GrobRect{xmin: 0, ymin: 0, xmax: 1, ymax: 1, fill: BuiltinColors["gray80"]}
bg.Draw(innerVP)
cols := []string{"red", "green", "blue", "cyan", "magenta", "yellow",
"white", "gray", "black"}
// Draw points in all shapes, three sizes and all builtin colors.
points := []Grob{}
x, y := 0.1, 0.1
for shape := DotPoint; shape <= StarPoint; shape++ {
for size := 2; size < 7; size += 2 {
y = 0.05
for _, col := range cols {
g := GrobPoint{
x: x,
y: y,
size: float64(size),
shape: shape,
color: BuiltinColors[col],
}
points = append(points, g)
y += 0.035
}
x += 0.021
}
}
x, y = 0.02, 0.05
for _, col := range cols {
g := GrobText{
x: x,
y: y,
text: col,
size: 10,
color: BuiltinColors[col],
vjust: 0.5,
hjust: 0,
}
points = append(points, g)
y += 0.035
}
x, y = 0.121, 0.36
for shape := DotPoint; shape <= StarPoint; shape++ {
dy := float64(shape%2) * 0.015
g := GrobText{
x: x,
y: y + dy,
text: shape.String(),
size: 10,
color: BuiltinColors["black"],
vjust: 0.5,
hjust: 0.5,
}
points = append(points, g)
x += 3 * 0.021
}
for _, grob := range points {
grob.Draw(innerVP)
}
// Draw lines with different styles and widths.
lines := []Grob{}
x, y = 0.1, 0.45
for lt := SolidLine; lt <= TwodashLine; lt++ {
x = 0.1
for size := 1; size < 8; size += 2 {
g := GrobLine{
x0: x,
y0: y,
x1: x + 0.18,
y1: y,
size: float64(size),
linetype: lt,
color: BuiltinColors["black"],
}
lines = append(lines, g)
x += 0.22
}
y += 0.04
}
for _, grob := range lines {
grob.Draw(innerVP)
}
// Draw rectangles
rectVP := innerVP.Sub(0.1, 0.7, 0.4, 0.3)
rect := []Grob{}
bgr := GrobRect{xmin: 0, ymin: 0, xmax: 1, ymax: 1, fill: BuiltinColors["gray40"]}
bgr.Draw(rectVP)
x, y = 0.0, 0.0
w, h := 0.5, 0.5
for _, col := range cols {
g := GrobRect{
xmin: x,
ymin: y,
xmax: x + w,
ymax: y + h,
fill: BuiltinColors[col],
}
rect = append(rect, g)
x += w
y += h
w /= 2
h /= 2
}
for _, grob := range rect {
grob.Draw(rectVP)
}
// Draw path
pathVP := innerVP.Sub(0.55, 0.7, 0.4, 0.3)
bgp := GrobRect{xmin: 0, ymin: 0, xmax: 1, ymax: 1, fill: BuiltinColors["gray"]}
bgp.Draw(pathVP)
sin := make([]struct{ x, y float64 }, 50)
for i := range sin {
k := float64(i) / float64(len(sin)-1)
x = k * 2 * math.Pi
println(float64(i)/float64(len(sin)), x, math.Sin(x))
y = 0.4 * math.Sin(x)
sin[i].x = k
sin[i].y = 0.55 + y
}
g := GrobPath{
points: sin,
size: 4,
linetype: SolidLine,
color: BuiltinColors["white"],
}
g.Draw(pathVP)
cos := make([]struct{ x, y float64 }, 25)
for i := range cos {
k := float64(i) / float64(len(cos)-1)
x = k * 4 * math.Pi
y = 0.3 * math.Cos(x)
cos[i].x = k
cos[i].y = 0.45 + y
}
g = GrobPath{
points: cos,
size: 2,
linetype: DottedLine,
color: BuiltinColors["green"],
}
g.Draw(pathVP)
pngCanvas.WriteTo(file)
file.Close()
}