Page History
| Warning |
|---|
This is preliminary and incomplete documentation. You've been warned. |
KIML defines a whole set of standard layout options that many layout algorithms support. Whether an algorithm supports a layout option depends on the option and on the algorithm. When an option is supported by an algorithm, that algorithm may override the option's default value. Algorithms may also provide more specialized documentation for layout options.
...
The option with identifier de.cau.cs.kieler.algorithm specifies which layout algorithm to use for the content of a composite nodea graph or subgraph. The value can be either the identifier of a layout algorithm or the identifier of a layout type. In the latter case the algorithm with highest priority of that type is applied.
The following layout types are predefined:
...
It is possible to set different values for this option on subgraphs of a hierarchical graph, where a subgraph is identified by a parent node. A layout algorithm is responsible to process only the direct content of a given parent node. An exception from this rule is made when the Layout Hierarchy option is active.
The following layout has been created by setting a force-based layout algorithm on the inner hierarchy level and a layer-based layout algorithm on the top level.
Available Algorithms and Libraries
- The KLay Project - Java implementations of standard layout approaches, augmented with special processing of graph features such as ports and edge labels.
- Randomizer - Distributes the nodes randomly; not very useful, but it can show how important a good layout is for understanding a graph.
Box Layout - Ignores edges, places all nodes in rows. Can be used to layout collections of unconnected boxes, such as Statechart regions.
- Fixed Layout - Does not compute a new layout, but leaves all nodes and edges where they are. If the Position and Bend Points options are set for the elements of the graph, the pre-defined layout is applied.
- OGDF (www.ogdf.net) - A self-contained C++ class library for the automatic layout of diagrams. The version that is shipped with KIELER is compiled as an executable that reads files in OGML format and outputs the computed concrete layout.
- Graphviz (www.graphviz.org) - An open source graph visualization tool with several graph layout programs, web and interactive graphical interfaces, auxiliary tools, libraries, and language bindings. Graphviz needs to be installed separately in order to be used within KIELER, since it is called in a separate process using the DOT language for communication.
Predefined Layout Types
- Layered - The layer-based method emphasizes the direction of edges by pointing as many edges as possible into the same direction. The nodes are arranged in layers and then reordered such that the number of edge crossings is minimized. Afterwards, concrete coordinates are computed for the nodes and edge bend points.
- Orthogonal - Orthogonal methods follow the "topology-shape-metrics" approach, which first applies a planarization technique, resulting in a planar representation of the graph, then compute an orthogonal shape, and finally determine concrete coordinates for nodes and edge bend points by applying a compaction method.
- Force - Layout algorithms that follow physical analogies by simulating a system of attractive and repulsive forces.
- Circular - Circular layout algorithms emphasize biconnected components of a graph by arranging them in circles. This is useful if a drawing is desired where such components are clearly grouped, or where cycles are shown as prominent properties of the graph.
- Tree - Specialized layout methods for trees, i.e. acyclic graphs. The regular structure of graphs that have no undirected cycles can be emphasized using an algorithm of this type.
Diagram Type
| Anchor | ||||
|---|---|---|---|---|
|
...
Overview
Content Tools