| 20 | ) |
| 21 | |
| 22 | func ExampleField() { |
| 23 | f := plotter.NewField(field{ |
| 24 | r: 17, c: 19, |
| 25 | fn: func(x, y float64) plotter.XY { |
| 26 | return plotter.XY{ |
| 27 | X: y, |
| 28 | Y: -x, |
| 29 | } |
| 30 | }, |
| 31 | }) |
| 32 | f.LineStyle.Width = 0.2 |
| 33 | |
| 34 | p := plot.New() |
| 35 | p.Title.Text = "Vector field" |
| 36 | p.X.Tick.Marker = integerTicks{} |
| 37 | p.Y.Tick.Marker = integerTicks{} |
| 38 | |
| 39 | p.Add(f) |
| 40 | |
| 41 | img := vgimg.New(250, 175) |
| 42 | dc := draw.New(img) |
| 43 | |
| 44 | p.Draw(dc) |
| 45 | w, err := os.Create("testdata/field.png") |
| 46 | if err != nil { |
| 47 | log.Panic(err) |
| 48 | } |
| 49 | png := vgimg.PngCanvas{Canvas: img} |
| 50 | if _, err = png.WriteTo(w); err != nil { |
| 51 | log.Panic(err) |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | func ExampleField_colors() { |
| 56 | f := plotter.NewField(field{ |