Drawing the ExprGraph with Graphviz (dot)

The encoding package of Gorgonia contains a function to marshal the ExprGraph into the dot language.

This make it possible to use the graphviz program to generate png or svg versions of the graph.

A simple way to do it:

package main

import (


func main() {
        g := gorgonia.NewGraph()

        var x, y *gorgonia.Node

        // define the expression
        x = gorgonia.NewScalar(g, gorgonia.Float64, gorgonia.WithName("x"))
        y = gorgonia.NewScalar(g, gorgonia.Float64, gorgonia.WithName("y"))
        gorgonia.Add(x, y)
        b, err := dot.Marshal(g)
        if err != nil {

Running this program and sending its output into the dot process produces a picture.

for example:

$ go run main.go | dot -Tsvg > dot-example.svg

produces this graph: