Graphviz (dot) control edge routing - graphviz

In this graph the bottom edge is not drawn symmetrical to the top edge:
digraph G {
A:ne -> A:nw;
A:sw -> A:se;
}
I want it to look more like a "fat snowman" with the edge A:sw -> A:se; looping below the node. Is there a way?

Short answer no - or not easily.
Loops seem to be placed from the rankdir direction. If rankdir is TB (down), loops seem to be placed "up".
It you're willing to work at it, you can run your graph twice, once with rankdir=TB, once with rankdir=BT - both times with -Tdot. Then you'd have to replace the offending edge with the equivalent edge from the other graph. [I hope this makes some sense]
Here is a tweaked version of your graph run with different values of rankdir:
digraph G {
A:ne -> A:nw;
A:sw -> A:se;
dummy [style=invis]
dummy -> A [style=invis]
}

Related

How do I force nodes to be drawn next to each other with Graphviz dot?

I'm looking to have a series of nodes in a row, joined by an edge. This works fine when the graph's rankdir is set to TB or BT, but it rearranges the nodes when I set it to LR or RL so they're no longer next to each other. Example images are included.
I've taken my code and stripped it down to it's minimum point for demonstration. The code is the same for both of the following graphs, aside from line 2 (which specifies rankdir):
digraph{
rankdir=LR;
node[shape=box,fontcolor=white,color=black,fillcolor=black,style=filled];
edge[dir=none,color=black];
Josh -> JoshParent;
JoshParent -> Hero;
JoshParent[shape=circle,label="",height=0.0001,width=0.0001];
{
rank=same;
Kae[label="Kae"];
Hero[label="Hero"];
Kae -> Hero;
}
Kae -> KaeParent;
Hero -> HeroParent;
KaeParent -> Liz;
KaeParent[shape=circle,label="",height=0.0001,width=0.0001];
HeroParent -> George;
HeroParent[shape=circle,label="",height=0.0001,width=0.0001];
{
rank=same;
George[label="George"];
Liz[label="Liz"];
Ocean[label="Ocean"];
Egg[label="Egg"];
Liz -> Ocean -> Egg;
}
}
This is what's shown with rankdir=TB:
This is what's shown with rankdir=LR:
As you can see, from the LR image, the nodes have been drawn in the order "Ocean, George, Egg", rather than "Ocean, Egg, George" as it is with the TB image.
You can force the order by adding an explicit but invisible edge from Egg to George:
Liz -> Ocean -> Egg; // last line of your code
Egg -> George[ style = invis ]; // additional edge
This produces
I don't have an explanation for the different behaviour between TB and LR, though.

Graphviz: How to place nodes only in lower semi-circle using circo layout?

In the attached figure, the nodes are arranged in a circle around the node. Is there a (possibly generic) way to arrange the nodes only in the lower semi-circle, without having to provide fixed coordinates for the nodes?
Edit: Would like to achieve something like shown in the image attached below. As one can see - all the nodes are arranged in the lower semi-circular region (this figure was made using CMap Tools).
The code is trivial, but pasting it anyway.
digraph semicircle {
rankdir="TD"
graph [nodesep="0.1", ranksep="0.3", center=true]
mindist="0.4"
S [label="Root", style="filled", fillcolor="greenyellow", shape="box"]
subgraph cluster1 {
rank="same"
A; B; C; D;
S -> {A, B, C, D};
} }
using dot/circo : graphviz version 2.40.1
I noted that circo placed nodes counter-clockwise, starting at 3 o'clock.
I added enough invisible nodes to fill the 2 through 10 o'clock positions.
To make the inter-nodal distances even more uniform I added:
node [shape=square style=rounded]
The result I got is this:
Try this:
digraph semicircle {
rankdir="TD"
graph [nodesep="0.1", ranksep="0.3", center=true, root=S]
mindist="0.4"
S [label="Root", style="filled", fillcolor="greenyellow", shape="box"]
subgraph cluster1 {
rank="same"
A
z1[style=invis label=""]
z2[style=invis label=""]
B; C; D;
S -> A
S -> z1,z2 [style=invis]
S -> { B, C, D};
}
}

Add extra edges to a digraph in Graphviz

I have a .dot digraph which shows a graph as I want (depicting relationship between some tables). I want to add redundant edges to the graph (to represent redundant relationships in the database which exist only to write queries less effortly). These redundat edges, which will be written in a "dotted" style, must not change the deployment of nodes in the graph.
In other words, there's edges which must affect the node positions to print the graph pretty, and other edges which must to be added after the node positions are already computed (which will be styled differently --light gray, dotted, etc; to show that they're not main edges).
Is there options in Graphviz to specify "extra" edges?
Use constraint=false and color=gray on those additional edges.
digraph G {
a -> b -> c -> d;
d -> a [constraint=false,color=gray]
a -> z -> x -> d;
}
Play with that on http://graphviz.it/#/rhlWBZsz

How to prevent edge labels from messing up the layout in graphviz?

I have a simple vertical graph that looks nice and symmetrical without any labels using the following code:
digraph test_alignment
{
{rank=same; a -> b;}
a -> c;
b -> c;
c -> d;
d -> e;
d -> f;
{rank=same; e -> f;}
}
I'd like to label the edge between A and B as well as the one between E and F, using the same string for each label. I'm expecting the same output, except with longer A->B and E->F edges bearing the same label.
Unfortunately, as soon as I add a label to one of these edges, the general layout looks slightly askew (the result is similar if I add a label to the E->F edge):
digraph test_alignment
{
{rank=same; a -> b [label="Label"];}
a -> c;
b -> c;
c -> d;
d -> e;
d -> f;
{rank=same; e -> f;}
}
I'm very new to graphviz and, following many questions on Stack Overflow, I have been experimenting with different combinations of rank and constraint, I tried using clusters to see if it would keep the top and bottom part properly aligned independently, and tried using a mix of dot, ccomp, gvpack and neato that produced similar results.
It always seems to boil down to the fact adding a label to the edge between nodes with the same rank affects how these nodes are positioned in a way I don't yet understand.
Am I missing something trivial, or am I attempting something I shouldn't instead of letting dot do its thing?
I'm using dot - graphviz version 2.36.0 (20140111.2315) and the linked pictures were produced with dot only (though I obtained similar results when using :
dot test_alignment.dot -Tpng -O
You may try to use the xlabel attribute, together with forcelabels if necessary. From the description:
... For edges, the label will be placed near the center of the edge. This
can be useful in dot to avoid the occasional problem when the use of
edge labels distorts the layout. ...

How to specify the length of an edge in graphviz?

In a directed graph, if there is a cycle, the graphviz makes that edge really short.
Is there a parameter that would let me change the length of the cyclic edge, so that
the graph looks a bit uniform.
digraph ER {
rankdir="LR";
//orientation=landscape;
node [shape=ellipse, fontsize=30];
{node [label="Original"] old;}
{node [label="Final"] new;}
{node [label="Intermediate"] ir;}
old -> ir [label="suggest", fontsize=30];
ir -> ir [label="validate", fontsize=30, len=f];
ir -> new [label = "finalize", fontsize=30];
}
Edit: Sorry, my answer will make edges longer, but not the self referencing edges you need.
len doesn't work in dot, but minlen does.
https://www.graphviz.org/doc/info/attrs.html#d:minlen
x->y
[minlen=5]
len doesn't works in dot, but you can try this trick:
digraph G {
rankdir=LR
a->b[dir=both]
b->c[dir=both,label=" "]// Just use the space to increase the edge length
}
If rankdir=TB, use label="\n" (repeat the \n as necessary) to increase the length.
I found that the following attribute nodesep worked to solve this problem with sfdp.
From nodesep | Graphviz:
For layouts other than dot
nodesep affects the spacing between loops on a single node, or multiedges between a pair of nodes.
Note that this is a graph attribute, so the value is the same for all edges in the graph.
From dot(1):
len=f sets the optimal length of an edge. The default is 1.0.
You can make the cyclic edge longer by adding a bunch of invisible cyclic edges before your visible one, like this:
digraph ER {
rankdir="LR";
//orientation=landscape;
node [shape=ellipse, fontsize=30];
{node [label="Original"] old;}
{node [label="Final"] new;}
{node [label="Intermediate"] ir;}
old -> ir [label="suggest", fontsize=30];
ir -> ir [style="invis"]
ir -> ir [style="invis"]
ir -> ir [style="invis"]
ir -> ir [style="invis"]
ir -> ir [label="validate", fontsize=30, len=f];
ir -> new [label = "finalize", fontsize=30];
}
In .dot language, the edge connects two notes with different ranks.
The length of edge is equal to (difference in ranks)*ranksep
default ranksep (in graph attribute) is 0.75 inch, so edge of adjacent nodes will be 0.75 inch.
To reduce the edge length, you set ranksep into a smaller value in graph atrribute
There's another approach that I now use for this:
I use graphviz to output the file in dot format
dot -T dot -Kneato -o ./positioned.dot ./input.dot
This file will contain the Bezier curve definitions for every edge.
I manually change the points to curve the way I want it to draw.
This may look a little daunting at first but once you figure out, how they work this isn't hard, I'm inching towards a script that will do this for me automatically
then re-run dot with your edited positioned file as the input
dot -T png -Kneato -O ./positioned.dot
With this approach I've pretty much turned dot into my text based visio replacement

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