Graphviz: change font for the whole graph?

Question

I am wondering if I can define an alternative font for the whole graph.

...
digraph script_concept {
graph [layout="dot",fontname="helvetica"];
...

According to this 1 older post the fontname atribute can be defined only separately:

Nodes and edges don't inherit the font of the graph, you need to specify them separately

Is there any other way, how to define the font globally?

Answer 1

No, there is no other way.

As in the forum post you linked, you have to define the default values separately (like the other attributes) at the beginning of your graphviz file:

digraph g {
 graph [fontname = "helvetica"];
 node [fontname = "helvetica"];
 edge [fontname = "helvetica"];
 ...
}

Answer 2

Not sure if this is a recent update, but you can change these at the command-line level using the -G, -E and -N attribute flags. That is, the following works for me:

$ dot -Tpng -Nfontname=Roboto -Nfontsize=10 \
    -Efontname=Roboto -Efontsize=10 \
    tree.dot > tree.png

Answer 3

However, there's one easy trick, if you are exporting svgs:

sed 's/Times,serif/Helvetica/g' thegraph.svg > thegraph_helvetica.svg

combine this with Make and all the horror will be hidden :) here's an example Makefile:

all: helvetica

svg:
    cat thegraph.dot | dot -Tsvg > thegraph.svg
helvetica: svg
    sed 's/Times,serif/Helvetica/g' thegraph.svg > thegraph_helvetica.svg