Increasing rank spacing in graphviz - d3.js

I have a graph laid out using D3 graphviz. It's laying out in a pretty dense way, and I'd like it to use more of the width of the screen.
I have tried adjusing the ranksep and the ratio, but neither seem to have any effect. I've also tried changing the node border, to no effect. Changing the edge minlength just makes the edges look floppy. I can try giving every node an invisible child, but that seems like a horrible hack.
For clarity, by rank, I mean the horizontal spacing between the columns of nodes. (The graph is laid out left to right.)
Ideally I'd be able to give it an aspect ratio and it'd make the most of that space to lay out the graph in a way that doesn't need too much acrobatics.
Am I missing something obvious?
I may well be using the options incorrectly
or the D3 graphviz implementation may not have those features?
Is there no good way to do this?

I have added :
size = "16.66,8.33!"; // 1200x600 at 72px/in, "!" to force
ratio = "fill"; // see https://graphviz.gitlab.io/_pages/doc/info/attrs.html#d:ratio
at the beginning of the graph declaration (just after digraph G {).
It renders a wider output.
Have a try and tell.

Related

GraphViz Dot. How to distribute elements around a boxed size?

I have a dot graphviz file that geneates the following output:
http://www.qlands.com/other_files/test.png
However the output is organized vertically. If I setup the size to be for example 8.27 inches; How can I distribute the elements around a box of 8.27 x 8.27 inches?
Your graph is a directed graph layed out with dot from left to right, and the first rank contains many nodes which results in a very high image.
The main tool to break up graphs with this problem is unflatten:
unflatten is a preprocessor to dot that is used to improve the aspect
ratio of graphs having many leaves or disconnected nodes. The usual
layout for such a graph is generally very wide or tall. unflatten
inserts invisible edges or adjusts the minlen on edges to improve
layout compaction.
You may combine this with other tools and techniques to get the result you want:
Use the unflatten utility - please see this answer for a detailed example using unflatten.
Use invisible edges to introduce new ranks (basically what unflatten does automatically, but with human inspiration... example also here)
If you need the output to be of this exact size, be sure to understand graphviz's various attributes which have an impact on it, such as size, margin, ratio... (see also this and yet another answer providing details)
Finally, you could simply use a different layout (neato for example)

D3 show text for nodes when zoomed

The number of nodes in my d3 graph is too large. So I built a zoom mechanism in that graph. Now the problem is, I just cannot display text for each nodes since they will overlap each other. However when I zoom in to the nodes, the space is enough to display texts.
So how do I show texts when the space is enough to show all of them without overlapping?
I have had this same problem in the past. Unfortunately optimal label placement is not an easy problem. To mitigate overlap effects one option is to use a restricted force layout for label placement. You can also try using callouts to allow the labels to move farther away from the nodes.
In the past I have implemented a sort of greedy collision detection based algorithm that goes something like:
sort the labels in decreasing priority
for each label in the list // so most important first
if the label does not overlap any placed labels
place the label and add it to my collision data structure (e.g. quad tree)
else
hide the label
Obviously this will have some non-optimal cases and it can be slow if you have a lot of animations going on. But when you have the option to zoom in to see more label and if your absolute number of labels is not too high then it works quite well. There are also a number of obvious ways to speed it up like restricting testing to only labels within the view (but then you need to update on pan).
You may find some helpful suggestions here including an implementation of collision detection.

d3 edges overlap node

I created a network in D3.js that updates links (both remove and add) as you move the slider back and forth.
However the edges overlap the nodes (as in edges are drawn ontop of the nodes...)
I think https://github.com/agfk/knowledge-maps/issues/1 looks at the issue but I'm not quite sure what it means.
I might have something to do with the order that the lines are drawn as opposed to the nodes but I don't know how to fix that. Svgs also don't come with z-indexes so I can manipulate it through css.
Any help would be appreciated! Thanks!
This link discusses how to determine the order in which elements are drawn. In your case, perhaps you want to draw the edges first and then the nodes:
https://groups.google.com/forum/?fromgroups=#!topic/d3-js/JCXKef_GRCQ

Annotate DOT graphs with images

I'm using PyDot to generate Graphviz/dot graphs in python. I would like to annotate my nodes and edges with images read from files, I've found in the documentation how to put an image as a node, but not how to put an image under a node or even less an edge.
http://www.graphviz.org/doc/info/attrs.html
http://www.graphviz.org/doc/info/shapes.html
http://www.graphviz.org/Documentation/html/shapehowto.html
Does anybody know how to do that?
You can use HTML in the labels for nodes and edges. You can find details here: http://www.graphviz.org/doc/info/shapes.html#html
Basically you can say something
"a" -> "b" [label = <<TABLE><TR><TD><IMG SRC="path/to/picture"/></TD></TR></TABLE>>]
You can add as many rows and columns as you want in the html labels. It's a little more verbose than standard text labels, but you can do a bit more with them.
One method which can work in cases where edges will always be drawn in the same position is to create a PNG with a transparent background and position the icon in the same place that your edge will be drawn, or use the labeldistance/labelangle attributes to move. I'm not familiar with PyDot but using SQL I would create a case to determine whether or not the image is displayed on the node..
Problem with this method is that the graphs which I'm working with are always positioned differently and will never be the same, so in an ideal case I'd like to add the image to the edge label, or under/to the right of the edge label etc. Did you ever manage to find a workaround?

Prevent overlapping records using graphviz and neato

I am building a dot file to represent computer hardware and the physical connections to a network switch and displays. I have it looking ok when processed by the dot program but I think I really want it processed by neato to create a more "free form" picture as it starts to grom. Right now when I run my large file with neato, everything is overlapping.
I am trying to figure out the syntax on where to define the overlap attribute. Below is a subset of my dot file.
graph g {
node [shape=record,height=.1];
PC8[label="{{<GigE1>GigE1|<GigE2>GigE2}|{<name>PC8}|{<dvi1>dvi1|<dvi2>dvi2|<dvi3>dvi3|<dvi4>dvi4}}"];
PC9[label="{{<GigE1>GigE1|<GigE2>GigE2}|{<name>PC9}|{<dvi1>dvi1|<dvi2>dvi2|<dvi3>dvi3|<dvi4>dvi4}}"];
C1[label = "{{<dvi1>dvi1}|{<name>C1}}"];
C2[label = "{{<dvi1>dvi1}|{<name>C2}}"];
C3[label = "{{<dvi1>dvi1}|{<name>C3}}"];
C4[label = "{{<dvi1>dvi1}|{<name>C4}}"];
D1[label = "{{<dvi1>dvi1}|{<name>D1}}"];
D2[label = "{{<dvi1>dvi1}|{<name>D2}}"];
"PC8":dvi1 -- "C1":dvi1;
"PC8":dvi2 -- "C2":dvi1;
"PC8":dvi3 -- "C3":dvi1;
"PC8":dvi4 -- "C4":dvi1;
"PC9":dvi1 -- "D1":dvi1;
"PC9":dvi2 -- "D2":dvi1;
}
Well, as with most questions...soon after I posted the I figured out the answer. I needed to add graph [overlap=false]; at the top of the file.
Do it like this:
graph g {
overlap = false;
node [shape=record,height=.1];
/* ... */
}
Setting overlap to false will work for neato as the community wiki answer says; however, if the graph exhibits any kind of regularity or symmetry, [overlap=false] will often mess it up by jiggling the nodes around to make them not overlap.
Use [overlap=false] as a last resort.
All node overlaps that are outputted from neato can be viewed as occurring because the nodes are too big relative to the edges. You can make any overlaps go away by making the nodes smaller and preserve symmetry in the graph drawing by setting [overlap=scale]. Quoting the Neato user manual:
To improve clarity, it is sometimes helpful to eliminate overlapping
nodes or edges. One way to eliminate node overlaps is just to scale up
the layout (in terms of the center points of the nodes) as much as
needed. This is enabled by setting the graph attribute overlap=scale.
This transformation preserves the overall geometric relationships in
the layout, but in bad cases can require high scale factors
As the documentation says [overlap=scale] can result in graph drawings that are unacceptably large, but if it does not its output is generally going to be better looking than [overlap=false].

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