Radial is a layout algorithm that places nodes on virtual concentric circles around a common center. This algorithm emphasizes tree structures within a diagram.
General Tab
Center Allocation Policy
Determines how the innermost nodes are chosen, i.e., the nodes on the smallest circle.
- Directed
- A node without incoming edges will be chosen as center node. If no such node exists, an arbitrary node is chosen.
- Centrality
- The center node will be chosen in such a way that a minimal number of circles is required.
- Weighted Centrality
- The node that is contained in the most interconnected paths in the diagram will be chosen as center node.
- Selected Nodes
- If there is a single selected node, that node is chosen as center node. If there are several selected nodes, these nodes are placed on the innermost circle. If there are no selected nodes, an arbitrary node is chosen as center node.
Circle Assignment Strategy
Determines how nodes are assigned to (conceptual) circles.
- Distance From Center
- With this strategy, nodes are assigned to circles in such a way that edges either connect nodes on subsequent circles or nodes placed on the same circle.
- Hierarchic
- With this strategy, nodes are assigned to circles in such a way that edges never connect nodes placed on the same circle.
- Dendrogram
- With this strategy, nodes are assigned to circles using a dendrogram layering strategy. Leaf nodes in tree graphs or nodes without neighbors further away from the center in general graphs are placed on the outermost circle. Nodes on inner circles are moved as far away from the center as possible but are placed before their neighbors on the outer circles.
Node Types
Determines the type of the nodes. For nodes of the same circle, the algorithm prefers to place nodes of the same type next to each other if this does not induce additional crossings or conflicts with other constraints. Note that the algorithm uses an additional local optimization heuristic to improve the placement with respect to node types and, thus, does not guarantee optimal results.
- None
- The nodes have no types.
- Defined by Color
- The type is defined by the node color. Nodes with the same color have the same type.
- Defined by Label
- The type is defined by the node label. Nodes with the same label have the same type.
Minimum Sector Distance
For circle assignment strategy Dendrogram, this value specifies the distance between neighboring nodes on the outermost circle that do not share the same predecessor on the previous circle. This distance is added to the minimum distance between nodes.
Minimal Circle Distance
Specifies the minimal distance between subsequent circles.
Minimal Node Distance
Specifies the minimal distance between adjacent nodes on the same circle.
Minimal Edge Distance
Specifies the minimum distance between two neighboring edges of the same circle.
Maximal Child Sector Size
Specifies the angular range of the sector that will be reserved for the children of a node. In this context, the child of a node n
is any node that is connected to n
and lies on a subsequent, larger circle. If the input graph is not a tree, a node may be child of several nodes. In this case it is assigned to the sector of one of this nodes.
Node Labeling
Specifies how to place node labels.
- None
- Automatic node labeling is deactivated.
- Horizontal
- All node labels are placed horizontally centered on the corresponding node. There will be no overlaps between node labels and other graph elements.
- Ray-like at Leaves
- Node labels of leaf nodes get the same orientation as the nodes’ incoming edge. These labels will be placed outside the node. Note that this style can only be applied to node labels having a free node label model.
- Consider Position
- The algorithm considers the current position of the node labels, i.e., the node labels keep their relative position and do not overlap with other graph elements.
Routing Style
- Straight
- Edge paths will be routed as a polyline with a certain number of bends.
- Arc
- Edge paths will be routed with multiple bends to create the impression of a smooth curve. Edge Smoothness controls the number of bends used.
- Bundled
- Edge paths will be routed such that the common parts of different edges are to some degree merged into a bundled part. Bundling strength controls how tightly the edges are bundled and influences the shape of the curves of bundled edges.
- Curved
- Edge paths will be routed in a curved style using cubic bezier splines.
- Radial Polyline
- Edge paths will be routed in a mixed radial and polyline style with a certain number of bends.
Edge Smoothness
Determines how many bends are created for Routing Style Arc
. The higher this value, the more bends are created.
Bundling strength
Determines how tightly the edges are merged/bundled for Routing Style Bundled
. The higher this value, the stronger the connection of the bundled edges.