// NewLabels returns a new Labels using the DefaultFont and
// the DefaultFontSize.
func NewLabels(d interface {
XYer
Labeller
}) (*Labels, error) {
xys, err := CopyXYs(d)
if err != nil {
return nil, err
}
if d.Len() != len(xys) {
return nil, errors.New("Number of points does not match the number of labels")
}
strs := make([]string, d.Len())
for i := range strs {
strs[i] = d.Label(i)
}
fnt, err := vg.MakeFont(DefaultFont, DefaultFontSize)
if err != nil {
return nil, err
}
return &Labels{
XYs: xys,
Labels: strs,
TextStyle: plot.TextStyle{Font: fnt},
}, nil
}
// New returns a new plot with some reasonable
// default settings.
func New() (*Plot, error) {
titleFont, err := vg.MakeFont(DefaultFont, 12)
if err != nil {
return nil, err
}
x, err := makeAxis()
if err != nil {
return nil, err
}
y, err := makeAxis()
if err != nil {
return nil, err
}
legend, err := makeLegend()
if err != nil {
return nil, err
}
p := &Plot{
BackgroundColor: color.White,
X: x,
Y: y,
Legend: legend,
}
p.Title.TextStyle = TextStyle{
Color: color.Black,
Font: titleFont,
}
return p, nil
}
// makeLegend returns a legend with the default
// parameter settings.
func makeLegend() (Legend, error) {
font, err := vg.MakeFont(DefaultFont, vg.Points(12))
if err != nil {
return Legend{}, err
}
return Legend{
ThumbnailWidth: vg.Points(20),
TextStyle: TextStyle{Font: font},
}, nil
}
// makeAxis returns a default Axis.
//
// The default range is (∞, ∞), and thus any finite
// value is less than Min and greater than Max.
func makeAxis() (Axis, error) {
labelFont, err := vg.MakeFont(DefaultFont, vg.Points(12))
if err != nil {
return Axis{}, err
}
tickFont, err := vg.MakeFont(DefaultFont, vg.Points(10))
if err != nil {
return Axis{}, err
}
a := Axis{
Min: math.Inf(1),
Max: math.Inf(-1),
LineStyle: LineStyle{
Color: color.Black,
Width: vg.Points(0.5),
},
Padding: vg.Points(5),
Scale: LinearScale,
}
a.Label.TextStyle = TextStyle{
Color: color.Black,
Font: labelFont,
}
a.Tick.Label = TextStyle{
Color: color.Black,
Font: tickFont,
}
a.Tick.LineStyle = LineStyle{
Color: color.Black,
Width: vg.Points(0.5),
}
a.Tick.Length = vg.Points(8)
a.Tick.Marker = DefaultTicks
return a, nil
}