How to add 3 dots in a graphviz network diagram?

Question

I have a simple graphviz network graph where I want to show the neural network architecture of my model:

DiagrammeR::grViz("digraph G {

rankdir = LR

{a b z} -> {x1, x2, x100} -> Y
                  
}")

which outputs to:

Now, I want to add 3 dots (vertically) after b in the first layer and after x2 in the second layer, indicating that there are more nodes in these layers than I can show in a presentation. For example, there is 100 nodes (units) in the second layer (x1, x2 ... x100).

What I want is similar to the 3 dots in this example (taken from this study/source):

score 2 · Accepted Answer · answered Jun 05 '21 at 21:44

There are two challenges

find a way to display the vertical ellipsis (the three dots)
keep the original nodes displayed in the desired order and location

The following works on my computer if output is SVG, but not png. If SVG is OK by you, here goes. If you need to directly create a png, an embedded image works.

digraph G {
rankdir = LR
splines=false  // straight lines, not curves
// define ellipsis nodes
E1[shape=none  label="&#8942;" fontsize=30]
E2[shape=none  label="&#8942;" fontsize=30]
{rank=same a b E1 z}       // align on same rank
{rank=same x1 x2 E2 x100}  // align on same rank

{a b z} -> {x1, x2, x100} -> Y

// invisible edges to order nodes
edge[style=invis]
a->b->E1->z 
x1->x2->E2->x100 
}

Giving (svg converted to png by Imagemagick):

How to add 3 dots in a graphviz network diagram?

1 Answers1