vgtex

Documentation

Overview

Package vgtex provides a vg.Canvas implementation for LaTeX, targeted at the TikZ/PGF LaTeX package: https://sourceforge.net/projects/pgf

vgtex generates PGF instructions that will be interpreted and rendered by LaTeX. vgtex allows to put any valid LaTeX notation inside plot's strings.

Example

An example of making a LaTeX plot.

package main

import (
	"image/color"
	"log"
	"os"

	"gonum.org/v1/plot"
	"gonum.org/v1/plot/plotter"
	"gonum.org/v1/plot/vg"
	"gonum.org/v1/plot/vg/draw"
	"gonum.org/v1/plot/vg/vgtex"
)

func main() {
	p := plot.New()
	// p.HideAxes()
	p.Title.Text = `A scatter plot: $\sqrt{\frac{e^{3i\pi}}{2\cos 3\pi}}$`
	p.Title.TextStyle.Font.Size = 16
	p.X.Label.Text = `$x = \eta$`
	p.Y.Label.Text = `$y$ is some $\Phi$`

	scatter1, err := plotter.NewScatter(plotter.XYs{{X: 1, Y: 1}, {X: 0, Y: 1}, {X: 0, Y: 0}})
	if err != nil {
		log.Fatal(err)
	}
	scatter1.Color = color.RGBA{R: 255, A: 200}

	scatter2, err := plotter.NewScatter(plotter.XYs{{X: 1, Y: 0}, {X: 1, Y: 0.5}})
	if err != nil {
		log.Fatal(err)
	}
	scatter2.GlyphStyle.Shape = draw.PyramidGlyph{}
	scatter2.GlyphStyle.Radius = 2
	scatter2.Color = color.RGBA{B: 255, A: 200}

	p.Add(scatter1, scatter2)

	txtFont := p.TextHandler.Cache().Lookup(
		p.X.Label.TextStyle.Font,
		p.X.Label.TextStyle.Font.Size,
	)

	c := vgtex.NewDocument(5*vg.Centimeter, 5*vg.Centimeter)
	p.Draw(draw.New(c))

	c.SetColor(color.Black)
	c.FillString(txtFont, vg.Point{X: 2.5 * vg.Centimeter, Y: 2.5 * vg.Centimeter}, "x")

	f, err := os.Create("testdata/scatter.tex")
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()

	if _, err = c.WriteTo(f); err != nil {
		log.Fatal(err)
	}
	err = f.Close()
	if err != nil {
		log.Fatal(err)
	}
}

Index

• type Canvas
  • func New(w, h vg.Length) *Canvas
  • func NewDocument(w, h vg.Length) *Canvas
  • func (c *Canvas) DrawImage(rect vg.Rectangle, img image.Image)
  • func (c *Canvas) Fill(p vg.Path)
  • func (c *Canvas) FillString(f font.Face, pt vg.Point, text string)
  • func (c *Canvas) Pop()
  • func (c *Canvas) Push()
  • func (c *Canvas) Rotate(rad float64)
  • func (c *Canvas) Scale(x, y float64)
  • func (c *Canvas) SetColor(clr color.Color)
  • func (c *Canvas) SetLineDash(pattern []vg.Length, offset vg.Length)
  • func (c *Canvas) SetLineWidth(w vg.Length)
  • func (c *Canvas) Size() (w, h vg.Length)
  • func (c *Canvas) Stroke(p vg.Path)
  • func (c *Canvas) Translate(pt vg.Point)
  • func (c *Canvas) WriteTo(w io.Writer) (int64, error)

Examples

• Package

Types

type Canvas

type Canvas struct {
	// contains filtered or unexported fields
}

Canvas implements the vg.Canvas interface, translating drawing primitives from gonum/plot to PGF.

func New

func New(w, h vg.Length) *Canvas

New returns a new LaTeX canvas.

func NewDocument

func NewDocument(w, h vg.Length) *Canvas

NewDocument returns a new LaTeX canvas that can be readily compiled into a standalone document.

func (*Canvas) DrawImage

func (c *Canvas) DrawImage(rect vg.Rectangle, img image.Image)

DrawImage implements the vg.Canvas.DrawImage method. DrawImage will first save the image inside a PNG file and have the generated LaTeX reference that file. The file name will be "gonum-pgf-image-<canvas-id>-<time.Now()>.png

func (*Canvas) Fill

func (c *Canvas) Fill(p vg.Path)

Fill implements the vg.Canvas.Fill method.

func (*Canvas) FillString

func (c *Canvas) FillString(f font.Face, pt vg.Point, text string)

FillString implements the vg.Canvas.FillString method.

func (*Canvas) Pop

func (c *Canvas) Pop()

Pop implements the vg.Canvas.Pop method.

func (*Canvas) Push

func (c *Canvas) Push()

Push implements the vg.Canvas.Push method.

func (*Canvas) Rotate

func (c *Canvas) Rotate(rad float64)

Rotate implements the vg.Canvas.Rotate method.

func (*Canvas) Scale

func (c *Canvas) Scale(x, y float64)

Scale implements the vg.Canvas.Scale method.

func (*Canvas) SetColor

func (c *Canvas) SetColor(clr color.Color)

SetColor implements the vg.Canvas.SetColor method.

func (*Canvas) SetLineDash

func (c *Canvas) SetLineDash(pattern []vg.Length, offset vg.Length)

SetLineDash implements the vg.Canvas.SetLineDash method.

func (*Canvas) SetLineWidth

func (c *Canvas) SetLineWidth(w vg.Length)

SetLineWidth implements the vg.Canvas.SetLineWidth method.

func (*Canvas) Size

func (c *Canvas) Size() (w, h vg.Length)

Size returns the width and height of the canvas.

func (*Canvas) Stroke

func (c *Canvas) Stroke(p vg.Path)

Stroke implements the vg.Canvas.Stroke method.

func (*Canvas) Translate

func (c *Canvas) Translate(pt vg.Point)

Translate implements the vg.Canvas.Translate method.

func (*Canvas) WriteTo

func (c *Canvas) WriteTo(w io.Writer) (int64, error)

WriteTo implements the io.WriterTo interface, writing a LaTeX/pgf plot.