// An example of making a bar chart.
func Example_barChart() *plot.Plot {
groupA := plotter.Values{20, 35, 30, 35, 27}
groupB := plotter.Values{25, 32, 34, 20, 25}
groupC := plotter.Values{12, 28, 15, 21, 8}
groupD := plotter.Values{30, 42, 6, 9, 12}
p, err := plot.New()
if err != nil {
panic(err)
}
p.Title.Text = "Bar chart"
p.Y.Label.Text = "Heights"
w := vg.Points(8)
barsA := must(plotter.NewBarChart(groupA, w)).(*plotter.BarChart)
barsA.Color = color.RGBA{R: 255, A: 255}
barsA.Offset = -w / 2
barsB := must(plotter.NewBarChart(groupB, w)).(*plotter.BarChart)
barsB.Color = color.RGBA{R: 196, G: 196, A: 255}
barsB.Offset = w / 2
barsC := must(plotter.NewBarChart(groupC, w)).(*plotter.BarChart)
barsC.Color = color.RGBA{B: 255, A: 255}
barsC.XMin = 6
barsC.Offset = -w / 2
barsD := must(plotter.NewBarChart(groupD, w)).(*plotter.BarChart)
barsD.Color = color.RGBA{B: 255, R: 255, A: 255}
barsD.XMin = 6
barsD.Offset = w / 2
p.Add(barsA, barsB, barsC, barsD)
p.Legend.Add("A", barsA)
p.Legend.Add("B", barsB)
p.Legend.Add("C", barsC)
p.Legend.Add("D", barsD)
p.Legend.Top = true
p.NominalX("Zero", "One", "Two", "Three", "Four", "",
"Six", "Seven", "Eight", "Nine", "Ten")
return p
}
func TestLegendAlignment(t *testing.T) {
font, err := vg.MakeFont(plot.DefaultFont, 10.822510822510822) // This font size gives an entry height of 10.
if err != nil {
t.Fatalf("failed to create font: %v", err)
}
l := plot.Legend{
ThumbnailWidth: vg.Points(20),
TextStyle: draw.TextStyle{Font: font},
}
for _, n := range []string{"A", "B", "C", "D"} {
b, err := plotter.NewBarChart(plotter.Values{0}, 1)
if err != nil {
t.Fatalf("failed to create bar chart %q: %v", n, err)
}
l.Add(n, b)
}
r := recorder.New(100)
c := draw.NewCanvas(r, 100, 100)
l.Draw(draw.Canvas{
Canvas: c.Canvas,
Rectangle: draw.Rectangle{
Min: draw.Point{0, 0},
Max: draw.Point{100, 100},
},
})
got := r.Actions
// want is a snapshot of the actions for the code above when the
// graphical output has been visually confirmed to be correct for
// the bar charts example show in gonum/plot#25.
want := []recorder.Action{
&recorder.SetColor{
Color: color.Gray16{},
},
&recorder.Fill{
Path: vg.Path{
{Type: vg.MoveComp, X: 80, Y: 30},
{Type: vg.LineComp, X: 80, Y: 40},
{Type: vg.LineComp, X: 100, Y: 40},
{Type: vg.LineComp, X: 100, Y: 30},
{Type: vg.CloseComp},
},
},
&recorder.SetColor{
Color: color.Gray16{},
},
&recorder.SetLineWidth{
Width: 1,
},
&recorder.SetLineDash{},
&recorder.Stroke{
Path: vg.Path{
{Type: vg.MoveComp, X: 80, Y: 30},
{Type: vg.LineComp, X: 80, Y: 40},
{Type: vg.LineComp, X: 100, Y: 40},
{Type: vg.LineComp, X: 100, Y: 30},
{Type: vg.LineComp, X: 80, Y: 30},
},
},
&recorder.SetColor{},
&recorder.FillString{
Font: string("Times-Roman"),
Size: 10.822510822510822,
X: 69.48051948051948,
Y: 30.82251082251082,
String: "A",
},
&recorder.SetColor{
Color: color.Gray16{},
},
&recorder.Fill{
Path: vg.Path{
{Type: vg.MoveComp, X: 80, Y: 20},
{Type: vg.LineComp, X: 80, Y: 30},
{Type: vg.LineComp, X: 100, Y: 30},
{Type: vg.LineComp, X: 100, Y: 20},
{Type: vg.CloseComp},
},
},
&recorder.SetColor{
Color: color.Gray16{},
},
&recorder.SetLineWidth{
Width: 1,
},
&recorder.SetLineDash{},
&recorder.Stroke{
Path: vg.Path{
{Type: vg.MoveComp, X: 80, Y: 20},
{Type: vg.LineComp, X: 80, Y: 30},
{Type: vg.LineComp, X: 100, Y: 30},
{Type: vg.LineComp, X: 100, Y: 20},
{Type: vg.LineComp, X: 80, Y: 20},
},
},
&recorder.SetColor{},
&recorder.FillString{
Font: string("Times-Roman"),
Size: 10.822510822510822,
X: 70.07575757575758,
Y: 20.82251082251082,
String: "B",
},
&recorder.SetColor{
Color: color.Gray16{
Y: uint16(0),
},
},
&recorder.Fill{
Path: vg.Path{
{Type: vg.MoveComp, X: 80, Y: 10},
{Type: vg.LineComp, X: 80, Y: 20},
{Type: vg.LineComp, X: 100, Y: 20},
{Type: vg.LineComp, X: 100, Y: 10},
{Type: vg.CloseComp},
},
},
&recorder.SetColor{
Color: color.Gray16{},
},
&recorder.SetLineWidth{
Width: 1,
},
&recorder.SetLineDash{},
&recorder.Stroke{
Path: vg.Path{
{Type: vg.MoveComp, X: 80, Y: 10},
{Type: vg.LineComp, X: 80, Y: 20},
{Type: vg.LineComp, X: 100, Y: 20},
{Type: vg.LineComp, X: 100, Y: 10},
{Type: vg.LineComp, X: 80, Y: 10},
},
},
&recorder.SetColor{},
&recorder.FillString{
Font: string("Times-Roman"),
Size: 10.822510822510822,
X: 70.07575757575758,
Y: 10.822510822510822,
String: "C",
},
&recorder.SetColor{
Color: color.Gray16{},
},
&recorder.Fill{
Path: vg.Path{
{Type: vg.MoveComp, X: 80, Y: 0},
{Type: vg.LineComp, X: 80, Y: 10},
{Type: vg.LineComp, X: 100, Y: 10},
{Type: vg.LineComp, X: 100, Y: 0},
{Type: vg.CloseComp},
},
},
&recorder.SetColor{
Color: color.Gray16{},
},
&recorder.SetLineWidth{
Width: 1,
},
&recorder.SetLineDash{},
&recorder.Stroke{
Path: vg.Path{
{Type: vg.MoveComp, X: 80, Y: 0},
{Type: vg.LineComp, X: 80, Y: 10},
{Type: vg.LineComp, X: 100, Y: 10},
{Type: vg.LineComp, X: 100, Y: 0},
{Type: vg.LineComp, X: 80, Y: 0},
},
},
&recorder.SetColor{},
&recorder.FillString{
Font: string("Times-Roman"),
Size: 10.822510822510822,
X: 69.48051948051948,
Y: 0.8225108225108215,
String: "D",
},
}
if !reflect.DeepEqual(got, want) {
t.Errorf("unexpected legend actions:\ngot:\n%s\nwant:\n%s", formatActions(got), formatActions(want))
}
}