// AddLines adds Line plotters to a plot.
// The variadic arguments must be either strings
// or plotter.XYers. Each plotter.XYer is added to
// the plot using the next color and dashes
// shape via the Color and Dashes functions.
// If a plotter.XYer is immediately preceeded by
// a string then a legend entry is added to the plot
// using the string as the name.
//
// If an error occurs then none of the plotters are added
// to the plot, and the error is returned.
func AddLines(plt *plot.Plot, vs ...interface{}) error {
var ps []plot.Plotter
names := make(map[*plotter.Line]string)
name := ""
var i int
for _, v := range vs {
switch t := v.(type) {
case string:
name = t
case plotter.XYer:
l, err := plotter.NewLine(t)
if err != nil {
return err
}
l.Color = Color(i)
l.Dashes = Dashes(i)
i++
ps = append(ps, l)
if name != "" {
names[l] = name
name = ""
}
default:
panic(fmt.Sprintf("AddLines handles strings and plotter.XYers, got %T", t))
}
}
plt.Add(ps...)
for p, n := range names {
plt.Legend.Add(n, p)
}
return nil
}
func lines(w vg.Length) (*plot.Plot, error) {
p, err := plot.New()
if err != nil {
return nil, err
}
pts := plotter.XYs{{0, 0}, {0, 1}, {1, 0}, {1, 1}}
line, err := plotter.NewLine(pts)
line.Width = w
if err != nil {
return nil, err
}
p.Add(line)
return p, nil
}
// AddStackedAreaPlots adds stacked area plot plotters to a plot.
// The variadic arguments must be either strings
// or plotter.Valuers. Each valuer adds a stacked area
// plot to the plot below the stacked area plots added
// before it. If a plotter.Valuer is immediately
// preceeded by a string then the string value is used to
// label the legend.
// Plots should be added in order of tallest to shortest,
// because they will be drawn in the order they are added
// (i.e. later plots will be painted over earlier plots).
//
// If an error occurs then none of the plotters are added
// to the plot, and the error is returned.
func AddStackedAreaPlots(plt *plot.Plot, xs plotter.Valuer, vs ...interface{}) error {
var ps []plot.Plotter
names := make(map[*plotter.Line]string)
name := ""
var i int
for _, v := range vs {
switch t := v.(type) {
case string:
name = t
case plotter.Valuer:
if xs.Len() != t.Len() {
return errors.New("X/Y length mismatch")
}
// Make a line plotter and set its style.
l, err := plotter.NewLine(combineXYs{xs: xs, ys: t})
if err != nil {
return err
}
l.LineStyle.Width = vg.Points(0)
color := Color(i)
i++
l.ShadeColor = &color
ps = append(ps, l)
if name != "" {
names[l] = name
name = ""
}
default:
panic(fmt.Sprintf("AddStackedAreaPlots handles strings and plotter.Valuers, got %T", t))
}
}
plt.Add(ps...)
for p, n := range names {
plt.Legend.Add(n, p)
}
return nil
}
func TestPersistency(t *testing.T) {
// Get some random points
rand.Seed(0) // The default random seed is 1.
n := 15
scatterData := randomPoints(n)
lineData := randomPoints(n)
linePointsData := randomPoints(n)
p, err := plot.New()
if err != nil {
t.Fatalf("error creating plot: %v\n", err)
}
p.Title.Text = "Plot Example"
p.X.Label.Text = "X"
p.Y.Label.Text = "Y"
// Use a custom tick marker function that computes the default
// tick marks and re-labels the major ticks with commas.
p.Y.Tick.Marker = commaTicks{}
// Draw a grid behind the data
p.Add(plotter.NewGrid())
// Make a scatter plotter and set its style.
s, err := plotter.NewScatter(scatterData)
if err != nil {
panic(err)
}
s.GlyphStyle.Color = color.RGBA{R: 255, B: 128, A: 255}
// Make a line plotter and set its style.
l, err := plotter.NewLine(lineData)
if err != nil {
panic(err)
}
l.LineStyle.Width = vg.Points(1)
l.LineStyle.Dashes = []vg.Length{vg.Points(5), vg.Points(5)}
l.LineStyle.Color = color.RGBA{B: 255, A: 255}
// Make a line plotter with points and set its style.
lpLine, lpPoints, err := plotter.NewLinePoints(linePointsData)
if err != nil {
panic(err)
}
lpLine.Color = color.RGBA{G: 255, A: 255}
lpPoints.Shape = draw.PyramidGlyph{}
lpPoints.Color = color.RGBA{R: 255, A: 255}
// Add the plotters to the plot, with a legend
// entry for each
p.Add(s, l, lpLine, lpPoints)
p.Legend.Add("scatter", s)
p.Legend.Add("line", l)
p.Legend.Add("line points", lpLine, lpPoints)
// Save the plot to a PNG file.
err = p.Save(4, 4, "test-persistency.png")
if err != nil {
t.Fatalf("error saving to PNG: %v\n", err)
}
defer os.Remove("test-persistency.png")
buf := new(bytes.Buffer)
enc := gob.NewEncoder(buf)
err = enc.Encode(p)
if err != nil {
t.Fatalf("error gob-encoding plot: %v\n", err)
}
// TODO(sbinet): impl. BinaryMarshal for plot.Plot and vg.Font
// {
// dec := gob.NewDecoder(buf)
// var p plot.Plot
// err = dec.Decode(&p)
// if err != nil {
// t.Fatalf("error gob-decoding plot: %v\n", err)
// }
// // Save the plot to a PNG file.
// err = p.Save(4, 4, "test-persistency-readback.png")
// if err != nil {
// t.Fatalf("error saving to PNG: %v\n", err)
// }
// defer os.Remove("test-persistency-readback.png")
// }
}