1. Field of the Invention
The present invention relates to a link relationship display apparatus for displaying a link relationship between nodes, and a control method and a program for the link relationship display apparatus.
2. Description of the Related Art
Recently, networks configured by data consisting of elements and links such as hyperlink relationships in the WWW, and quotation relationships of papers are often visualized, thereby grasping structural characteristics of the networks. In known techniques for visualizing network data, coordinate positions of graphs are calculated by using a dynamic model such as disclosed in JP-A-2004-318739 and Kamada, T., and Kawai, S., “An Algorithm for Drawing General Undirected Graph”, Information Processing Letters, 32, 7-15, 1989.
However, the conventional technique has a following problems: When the scale of a network is enlarged and the number of nodes to be displayed is increased, it is difficult to make a displayed graph visually comprehensive. In addition, when the number of nodes to be displayed increases, the load of calculation of placement coordinates for displaying the nodes disadvantageously increases.
The invention has been conducted in view of the above-discussed problems. The invention provides a link relationship display apparatus which can indicate structural characteristics of a network in an easy-to-understand manner even when the number of nodes is increased, and a control method and a program for the link relationship display apparatus.
The invention also provides a link relationship display apparatus in which the load of calculation of placement coordinates when nodes are to be displayed can be reduced, and a control method and a program for the link relationship display apparatus.
According to an aspect of the present invention, a link relationship display apparatus for displaying a link relationship between a first node group and a second node group, each of which includes at least one node, the link relationship display apparatus includes: a unit to set one of the first node group and the second node group as a master node group, and another one as a slave node group; a unit to extract a node of an abbreviated display target node group from the slave node group, the node having a degree of link coincidence which exceeds a predetermined threshold, the degree of link coincidence indicating a ratio of a common node to be linked in the master node group; a unit to determine a representative position coordinate of the node of the abbreviated display target node group; and a display unit to display a corresponding abbreviated display target node group in a vicinity of the representative position coordinate.
According to another aspect of the present invention, a method of controlling a link relationship display apparatus for displaying a link relationship between a first node group and a second node group, each of which includes at least one node, the method includes: setting one of the first node group and the second node group as a master node group, and another one as a slave node group; extracting a nodes of an abbreviated display target node group from the slave node group, the node having a degree of link coincidence which exceeds a predetermined threshold, the degree of link coincidence indicating a ratio of a common node to be linked in the master node group; determining a representative position coordinate of the node of the abbreviated display target node group; and displaying a corresponding abbreviated display target node group in a vicinity of the representative position coordinate.
According to another aspect of the present invention, a storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer to perform a function for controlling a link relationship display apparatus for displaying a link relationship between a first node group and a second node group, each of which includes at least one node, the function includes the steps of: setting one of the first node group and the second node group as a master node group, and another one as a slave node group; extracting a nodes of an abbreviated display target node group from the slave node group, the node having a degree of link coincidence which exceeds a predetermined threshold, the degree of link coincidence indicating a ratio of a common node to be linked in the master node group; determining a representative position coordinate of the node of the abbreviated display target node group; and displaying a corresponding abbreviated display target node group in a vicinity of the representative position coordinate.
Embodiments of the present invention will be described in detail based on the following figures, wherein:
In the invention, the link relationship display apparatus displays a link relationship between first and second node groups each including at least one node, based on information indicating the link relationship between the first and second node groups. The link relationship display apparatus sets one of the first node group and the second node group as a master node group, and sets the other one of the groups as a slave node group. The link relationship display apparatus extracts, from nodes included in the slave node group, nodes having a degree of link coincidence which exceeds a predetermined threshold, the degree of link coincidence indicating a ratio of common nodes in the master node group to be linked. Then, the link relationship display apparatus determines a representative position coordinate for each of the extracted abbreviated display target node groups, and visualizes and displays the link relationship between the first node group and the second node group while placing abbreviated display target node groups in the vicinities of the corresponding representative position coordinates.
According to the invention, even when the number of nodes to be displayed is increased, the link relationship display apparatus can perform the abbreviated display on the set one of the first and second node groups, the one node group having link coincidence with a predetermined ratio or higher. Therefore, structural characteristics of a network can be indicated to the user in an easy-to-understand manner.
In one embodiment of the invention, in predetermined ranges of the determined representative position coordinates, the display means displays corresponding abbreviated display target node groups. By means of the abbreviated display of the abbreviated display target node groups, it is possible to indicate the structural characteristics to the user in an easy-to-understand manner.
In one embodiment of the invention, the display means displays nodes included in the abbreviated display target node groups with being arranged at predetermined intervals. By means of the abbreviated display of the abbreviated display target node groups, it is possible to indicate the structural characteristics to the user in an easy-to-understand manner.
Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
The link relationship display apparatus 1 performs the visualization of a network configured by a first node group and a second node group based on data indicating a link relationship between the first node group and the second mode group. Hereinafter, description will be made by way of a specific example.
In the specific example used in this embodiment, the first node group includes three nodes {A, B, C}, and the second node group includes eight nodes {a, b, c, d, e, f, g, h}. The first node group and the second node group have a link relationship shown in
In order to realize the above-described processing, the link relationship display apparatus 1 of the invention has functions which will be described below.
The master node group setting section 20 sets one of the first node group and the second node group as a master node group, and sets the other one of the groups as a slave node group. The master node group is a node group which is not an abbreviation target, and the slave node group is a node group which is an abbreviation target. In the setting of the master node group and the slave node group, the first node group may be set as the master node group by default, or the user may specify which one is set as the master node group. Alternatively, the processor 10 may count the number of nodes included in the master/slave node groups, the node group which includes the larger number of nodes may be intended to be set an abbreviation target, the node group including the smaller number of nodes may be set as the master node group, and the other node group may be set as the slave node group. As a method other than the above-mentioned methods, the processor 10 may calculate the number of nodes which can be abbreviated in both cases where the first node group is set as the master node group and where the second node group is set as the master node group, and may set the node group including the smaller number of nodes which can be abbreviated, as the master node group.
The abbreviated display target node group retrieving section 22 extracts, from the nodes included in the slave node group, nodes having a degree of link coincidence which exceeds a predetermined threshold, as abbreviated display target node groups. The degree of link coincidence indicates a ratio of common nodes in the master node group to be linked. Specifically, the processor 10 generates, on the memory 12, a table shown in
The representative position coordinate calculating section 24 handles a node group retrieved by the abbreviated display target node group retrieving section 22 as one node, and calculates representative position coordinates of node groups. The processor 10 regards an abbreviated display target node group obtained by the abbreviated display target node group retrieving section 22 as one node, and calculates the coordinate positions of the nodes. The example used in the embodiment will be described. Each of the node groups {a, b, c, d, e}, {g, h}, and {i, j, k} is regarded as one node, and two-dimensional coordinate values for placing the respective nodes are calculated. The calculated two-dimensional coordinate values are set as the representative position coordinates of the abbreviated display target node groups. In the calculation of the two-dimensional coordinate values, the technique of calculating coordinates of a node based on the dynamic model described in Kamada, T., & Kawai, S., ibid. is used.
The bipartite graph image generating section 26 generates an output image obtained by visualizing the network data, on the basis of the position coordinates of the nodes calculated by the representative position coordinate calculating section 24. A node which is not an abbreviation display target is processed in the same manner as in the case where the abbreviation is not performed, and hence its description is omitted.
The production of a display image of an abbreviated display target node group will be described with reference to
The graph display section 28 includes the display 16 of the link relationship display apparatus 1. The processor 10 outputs the image data stored in the video memory of the graphic interface 14 to the display 16, so that the generated bipartite graph image is displayed on the display 16.
Hereinafter, the operation of visualizing processing of network data by the link relationship display apparatus 1 of the embodiment of the invention will be described in detail.
According to the above-described link relationship display apparatus of the embodiment of the invention, even when the number of nodes to be displayed is increased, it is possible to perform the abbreviated display on a node group having a degree link coincidence which is equal to or larger than a predetermined ratio, with respect to the set one of the first node group and the second node group. Therefore, it is possible to show structural characteristics of the network in an easy-to-understand manner.
The invention is not restricted to the above-described embodiment.
For example, in the above-described embodiment, the nodes of the abbreviated display target node group are displayed with being obliquely superimposed. However, the display may be performed in other various ways. The nodes may be horizontally superimposed as shown in
The entire disclosure of Japanese Patent Application No. 2005-333039 filed on Nov. 17, 2005 including specification, claims, drawings and abstract is incorporated herein by reference in its entirety.
Number | Date | Country | Kind |
---|---|---|---|
2005-333039 | Nov 2005 | JP | national |