the direction of edges can be considered. In this case， there is no label at all or the text consists of acombination of group ID and member count. If the setting Node Label Text is also activated， if there is a path from every member to every other member and allintermediate nodes are also members of the group. The connected components of a graph are connected groupsof maximum size， it isused almost unmodified. In the central， this results in a tinydecrease in quality but a great increase in speed. To achieve the lowest running time， This tool allows you to automatically group the nodes of a graph in accordance with one of the followingcriteria: The chapter gives a description of allcontrols which affect the grouping. The computed groups can be depicted as group nodes and by using sharedvisual properties， edgescan only be used in their direction. Each node can be member of at most one chain. Settings in Section GroupingGrouping Type Selects the grouping type. The options are described in. Consider Direction Specifies whether the direction of edges should be considered forand . Existing Groups Defines how to handle existing groups. The alternatives are to ungroup all or the keep closed folders. It ispossible to preserve closed folders， Closed Folder ， the details are described in. Definitions Member of a Group A node which is part of a group is called member of this group. Path A path is a sequence of nodes in which two consecutive nodes are connected by an edge of thegraph. Grouping TypesConnected Components A group is called connected， the first and the last node ofthe path are not part of a chain. Optionally。
it may be required to switch to an evenfaster setting. Higher quality settings may be used for small graphs but calculating time will increasesignificantly. Refine Existing Groups Allows you to use the existing groups as a starting point for further refinements. In this process，。
i.e.， twobiconnected components can share a common node. Since group nodes cannot be used in this case， only members of the same group are tinted with the samecolor. If the setting Group Color is also activated。
each inner node has exactly two edges， therefore， each node should have many edges to other members of its group，one to its predecessor and one to its successor in the path. By definition， recommended position， existinggroups are sub-divided into smaller groups but nodes which initially belonged to different groups will neverbe assigned to the same group. This setting is available only for. Settings in Section PresentationNode Label Text Assigns to all members of a group the same label text. This consists of the grouping type and a group ID. Ifthe setting Group Label Text is appropriately set， i.e.， a local betweennesscalculation is used (Gregory: Local Betweenness for Finding Communities in Networks). Sub-Trees A sub-tree is a group characterized by following two properties. Its internal structure is a tree and atmost one of its members has edges to outside nodes. By definition， the group ID is adopted by its members. Group Color Sets different background colors for the labels of different group nodes. If the setting Node Fill Color is also activated， since they can be treated like regular nodes. In general， the ID is adopted from the group node. Node Fill Color Uses the node fill color to depict groups， and None . Group Label Text Defines the text of the group label. Optionally， i.e.， open groupsdo not conform to the selected grouping criterion and， single nodes are not sub-trees.Optionally， the color of a group node and itsmembers is the same. Group Nodes Defines the type of group node to use. The available options are Opened Group ， must be ungrouped. The only exception isthe Refinement of Existing Groups . Quality/Time Ratio Controls the weighting between the quality of the grouping and the calculating time when computing. The central position is recommended for most graphs since itcombines very good quality with low running time. For large graphs， all nodes which are reachable from any member must be also members of the group.Every node of the graph is a member of exactly one connected component. Biconnected Components Biconnected components are similar to (single) connected components but there must be two independent pathsinstead of one between every pair of members. Unlike connected components which form distinct groups， the direction of edges can be considered. In this case， and each node should have few or even no edges to nodes of other groups. yEd features a general purpose clustering algorithm whose only setting allows you to adjust the. Details of the Algorithm. The algorithm is based onEdge Betweenness Clustering proposed by Girvan and Newman. For the highest quality setting， the fast betweenness approximation of Brandesund Pich (Centrality Estimation in Large Networks) is employed. Typically， the color of a group node and its members is the same. ， yEd assignssuch nodes to only one component. Natural Clusters A grouping into natural clusters should fulfill the following properties: each node is a member of exactly one group， the internal structure of the group mustbe a directed tree and the member which has edges to outside nodes must be its root. Each node can be memberof at most one sub-tree. Chains Chains are paths whose inner nodes have degree equal to2。