Plotting a large graph in igraph - python

I created a Graph using the igraph package (http://hal.elte.hu/~nepusz/development/igraph/tutorial/tutorial.html), and I'm trying to plot it using the Plot() function. My graph has ~20000 Vertices and ~30000 Edges, and I'm struggling to find a way to plot it such that it looks remotely presentable.
Distributive Recursive Layout gives decent results, but it doesn't make much sense since vertices are arbitrarily grouped together. Fiddling with the vertex,label,edge sizes doesn't help much either.
Could someone, who has experience with plots of this size, suggest a suitable layout to data of this size?

Related

Generate schematic (geographic) diagram from graph

I would like to know how best to generate a schematic diagram, something like this, from a graph (created using the Python NetworkX library) that contains the latitude and longitude of each node (city) and the lines connecting them in the Indian railway network.
The cities (nodes) should be located reasonably close to their actual position, but not necessarily exactly. I am OK with using the plate carrée projection that simply maps lat/long onto X/Y in the diagram.
The rail lines (edges) can be straight lines or even curves if it fits better.
On the diagram should be displayed the cities (preferably as dots) along with a short (max 4 characters) label for each, the lines connecting them, and a single label for each line (the given example has quite long labels for the lines).
Preferably the amount of manual tweaking of coordinates to get things to fit should be minimised.
Using Graphviz was my first idea. But I don't know how well neato/fdp (required for fixed positioning of nodes) will perform with large numbers of nodes/edges. Also, making Graphviz display labels separately outside the nodes (rather than inline) seems to need a lot of manual positioning of each label, which would be pretty boring. Is there any better way to get this kind of layout?
Doable (https://forum.graphviz.org/t/another-stupid-graphviz-trick-geographic-graphs/256), but does not seem to use many Graphviz features. In addition to tools mentioned in the link, maybe consider pikchr (https://pikchr.org/home/doc/trunk/homepage.md)

A framework for animating a network graph algorithm in Python

I’m looking for a way to animate a network graph algorithm in Python.
What I need to do is to draw a (large) network graph and manipulate it (add/remove vertices, add/remove edges, change vertices size and/or color, change edges colors, etc.), without having to redraw the entire graph for every frame.
I found several similar questions (this one for example) but they all either regard static plotting of network graphs or are very old and the examples doesn't work.
3Blue1Brown's manim animation engine may be something to consider. It supports LaTeX-style graphics and has quite an active community.

Adding sub nodes to networkx (with image)

I would like to create a networkx graph that looks more or less like this, but I haven't been able to find a way for it to display the way I need. The large nodes and edges display fine, but I haven't been able to find how to add the small nodes.
networkx.draw() has an optional argument node_size:
node_size (scalar or array, optional (default=300)) – Size of nodes. If an array is specified it must be the same length as nodelist.
If you want to draw nodes with various sizes, you should specify the array of sizes. You can also use some kind of list generator.
P.S. I don't recommend to use basic networkx drawing functional. There are many powerful visualization libraries better than networkx. Even in networkx docs you can find the same opinion. One can use Gephi, Graphviz (with various libraries) or Cytoscape for really HUGE graphs.

What is the best way to create a figure with distributions as insets in python?

I created a graph in MATLAB (see figure below) such that around every data point there is a data distribution plotted (grey area plots). The way I did it in MATLAB was to create a set of axes for every distribution curve and then plot the curves without showing those axes at every point of the data curve. I also used a command 'linkaxes' to set figure limits for all the curves at once.
I must say that this is far from an elegant solution and I had many troubles with saving this figure in the correct aspect ratio settings. All in all I couldn't find any other useful option in MATLAB.
Is there a more elegant solution for such types of graphs in Python? I am not that much interested in how to do the areas highlighted, but how to place a set of curves(distributions) exactly at the positions of the main data curve points.
Thank you!

Placing vertices of graphs + wxpython

I have to draw graphs along with edges according to a file input by the user. I am using wxPython for the same.
Once the positions are clear I can easily create circles and edges between the nodes but
I have a problem that given a panel to draw on is there any way I can get to know optimum positions for the vertices to be if I know the number of vertices ?
By optimum I mean simply that its readable what has been drawn and written along with it.....
So say that I have to draw 3 vertices I just want that I am able to clearly get the coordinates of where to place the nodes and if I can make the system automated....
Please help ....
You want a Graph Drawing algorithm. There is ongoing research in this area, but a simple force-directed algorithm can give good results for small graphs. Look at this wikipedia article for the algorithm. You can also get some open source libraries that handle this problem, like NodeBox and Graphvis.
Also a good lib: igraph
It offers a nice collection of layout algorithms

Categories

Resources