1
2
3
4
5 package text_test
6
7 import (
8 "image/color"
9 "log"
10 "math"
11 "testing"
12
13 "gonum.org/v1/plot"
14 "gonum.org/v1/plot/cmpimg"
15 "gonum.org/v1/plot/font"
16 "gonum.org/v1/plot/font/liberation"
17 "gonum.org/v1/plot/plotter"
18 "gonum.org/v1/plot/text"
19 "gonum.org/v1/plot/vg"
20 "gonum.org/v1/plot/vg/draw"
21 )
22
23 func ExampleLatex() {
24 fonts := font.NewCache(liberation.Collection())
25 plot.DefaultTextHandler = text.Latex{
26 Fonts: fonts,
27 }
28
29 p := plot.New()
30 p.Title.Text = `$f(x) = \sqrt{\alpha x \Gamma}$`
31 p.X.Label.Text = `$\frac{\sqrt{x}}{2\pi\Gamma\gamma}$`
32 p.Y.Label.Text = `$\beta$`
33
34 p.X.Min = -1
35 p.X.Max = +1
36 p.Y.Min = -1
37 p.Y.Max = +1
38
39 labels, err := plotter.NewLabels(plotter.XYLabels{
40 XYs: []plotter.XY{
41 {X: +0.0, Y: +0.0},
42 {X: -0.9, Y: -0.9},
43 {X: +0.6, Y: +0.0},
44 {X: +0.5, Y: -0.9},
45 },
46 Labels: []string{
47 `$\frac{\sqrt{x}}{2\pi\Gamma\gamma}$`,
48 `$LaTeX$`,
49 "plain",
50 `$\frac{\sqrt{x}}{2\beta}$`,
51 },
52 })
53 if err != nil {
54 log.Fatalf("could not create labels: %+v", err)
55 }
56 labels.TextStyle[0].Font.Size = 24
57 labels.TextStyle[0].Color = color.RGBA{B: 255, A: 255}
58 labels.TextStyle[0].XAlign = draw.XCenter
59 labels.TextStyle[0].YAlign = draw.YCenter
60
61 labels.TextStyle[1].Font.Size = 24
62 labels.TextStyle[1].Color = color.RGBA{R: 255, A: 255}
63 labels.TextStyle[1].Rotation = math.Pi / 4
64
65 labels.TextStyle[2].Font.Size = 24
66 labels.TextStyle[2].Rotation = math.Pi / 4
67 labels.TextStyle[2].YAlign = draw.YCenter
68 labels.TextStyle[2].Handler = &text.Plain{Fonts: fonts}
69
70 labels.TextStyle[3].Font.Size = 24
71 labels.TextStyle[3].Rotation = math.Pi / 2
72
73 p.Add(labels)
74 p.Add(plotter.NewGlyphBoxes())
75 p.Add(plotter.NewGrid())
76
77 err = p.Save(10*vg.Centimeter, 5*vg.Centimeter, "testdata/latex.png")
78 if err != nil {
79 log.Fatalf("could not save plot: %+v", err)
80 }
81 }
82
83 func TestLatex(t *testing.T) {
84 cmpimg.CheckPlot(ExampleLatex, t, "latex.png")
85 }
86
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