Radial tree with plotly and Networkx

[bixin]

Hello everyone!
Quite new into data viz.
I use Python3, Networkx, and windows 64B.

Objective: Trying to plot a radial plot following @empet example:

A radial tree | scatter chart made by Empet | plotly

So far, I got X, Y nodes and edges using NetWorkx, and I have got ploted this tipe of graphic:

Networkx and Plotly edges do not match

@xpotion Your definition of edge trace does not assign the right coordinates to the edge ends. I copied your csv file from the above post, saved it with the name data-spanning.csv, and modified your code such that Plotly can now generate the right graph. Here is the updated code: https://plot.ly/~empet/14899 [minim-spanning-tree]

Problems encountered:
I can’t find the way to install igraph neither pygraphviz.
even checking forums like this one:

howto install pygraphviz on windows 10 64bit

Setting the questions:
When looking at @empet code inside layout he loops over all line traces, and append this type of coor:
},
“path”: “M0.401878291468 -0.91569309206, C0.602817437202 -1.37353963809, 0.544982894659 1.39749548999, 0.726643859546 1.86332731998”,
“type”: “path”
},
I belive, the first two set numbers are starting point the midle ones are lines’ curve and the last two are the end point of the vector.
With Networkx I only have beginning and end.

Questions:

1. Is there any way I could still plot same radial tree with starting ending edges and nodes?
2. Does he get those coor using pygraphviz? could I get them with networkx?
3. I need the depth of each node. how can I get it?

Any help is welcome. Sorry for not being able to provide any code. but basically all I have is this

Networkx and Plotly edges do not match

@xpotion Your definition of edge trace does not assign the right coordinates to the edge ends. I copied your csv file from the above post, saved it with the name data-spanning.csv, and modified your code such that Plotly can now generate the right graph. Here is the updated code: https://plot.ly/~empet/14899 [minim-spanning-tree]

Thank you very much to all
I hope you have a nice summer day,

[empet]

@bixin To generate a radial tree like in the link above, I didn’t use igraph or pygraphviz,
because none of them provides the layout for such a graph.

The steps in the definition of such a layout are the following:

• defined a class Tree

• implemented this algorithm https://link.springer.com/chapter/10.1007/3-540-36151-0_32 (it can be downloaded for free) to get this usual tree https://plot.ly/~empet/14305/a-tree-with-improved-walker-layout-1/

• mapped the nodes of the above tree to circles with the center at root, and radius equal to the vertical distance from each node to the root. The polar angle associated to each node is:

  theta=(2*np.pi)*(x_node-xmin)/(xmax-xmin)-np.pi/2

  where x_node is the x-coord of that node in the usual layout, while xmin, xmax are the min, max values of nodes in the linear layout.

• the tree edges are plotted as cubic Bezier curves. Plotly defines such a Bezier curve as a shape https://plot.ly/python/shapes/
  The four points in the path string you pasted here are the Bezier control points

[bixin]

@empet thanks a lot! I’ll give it a go! thanks for helping