SugiyamaLayout

class omni.kit.widget.graph.graph_layout.SugiyamaLayout(edges=[], vertical_distance=10.0, horizontal_distance=10.0)

Bases: object

Compute the coordinates for drawing directed graphs following the method developed by Sugiyama.

This method consists of four phases: 1. Cycle Removal 2. Layer Assignment 3. Crossing Reduction 4. Coordinate Assignment

As input it takes the list of edges in the following format: [(vertex1, vertex2), (vertex3, vertex4), … ]

Once the object is created, it’s possible to get the node layer number immediately.

To get the node positions, it’s necessary to set each node’s size and call `update_positions`.

Follows closely to the following papers: [1] “An Efficient Implementation of Sugiyama’s Algorithm for Layered Graph Drawing” Eiglsperger Siebenhaller Kaufmann [2] “Sugiyama Algorithm” Nikolov [3] “Graph Drawing Algorithms in Information Visualization” Frishman

Methods

__init__([edges, vertical_distance, ...])
get_layer(vertex)	The layer id of the node
get_position(vertex)	The position of the node
set_size(vertex, width, height)	Set the size of the node
update_positions()	Coordinate Assignment

__init__(edges=[], vertical_distance=10.0, horizontal_distance=10.0)

class Node(id)

Bases: object

Temporary node that caches all the intermediate compute data

add_upstream(node)

Add the upstream node. It will add current node to downstream as well.

get_layer(vertex)

The layer id of the node

get_position(vertex)

The position of the node

set_size(vertex, width, height)

Set the size of the node

update_positions()

4. Coordinate Assignment